Inter-University Research Institute Corporation
National Institutes of Natural Sciences

National Astronomical Observatory of Japan

NAOJ

2023

https://www.nao.ac.jp/en/
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Pulling Back the Veil of Stars

A menagerie of heavenly bodies photographed by Hyper
Suprime-Cam on the Subaru Telescope. This image captured aquickly-moving asteroid in our Solar System (dotted blue line
at the bottom-center), a few stars in our Milky Way Galaxy, andcountless distant galaxies billions of light-years away.

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Astronomy is one of humanity's oldest sciences. It
started with making calendars for farming and hunting,and has now grown to include the fundamental desire
held by everyone to “understand our place in the grandscheme of the Universe.” Modern perspectives on the
Universe, primarily the “Big Bang Theory” establishedin the latter half of the 20th century, laid the scientificfoundation to understand the unified dynamism ofmaterial evolution, explaining the Earth in the context
of the history of the Universe, life in the context of thehistory of the Earth, and humanity in the context of thehistory of life. And with the start of the new century wehave entered the age of investigating planets outside
the Solar System and examining the possibility of
extraterrestrial life. By observing various hitherto
unknown cosmic phenomena, NAOJ plays a role in"creating new views of nature" which will connect the
Universe, life, and ourselves together.

Cover Photo: ALMA Antennas and the Southern Milky Way
Back Cover Photo: Subaru Telescope and the stars of the northern sky
Production Staff: Masaaki Hiramatsu (Editor in Chief), Hiroyuki Takata, Maki Kubo, Ramsey Lundock (NAOJ Publications Office)Published by the National Astronomical Observatory of Japan ©2023 NAOJ

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Subaru Telescope
An Eye Scanning the Breadthand Depth of the Universe

NAOJ's optical-infrared Subaru Telescope located near thesummit of Maunakea in Hawai‘i boasts a world-class apertureof 8.2 meters. Making maximum use of this potential, theSubaru Telescope scans the breadth and depth of the night
sky to investigate the origin of cosmic structure.

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The summit region of Maunakea in Hawai‘i: the silhouetteof the Subaru Telescope enclosure floating above a sea ofclouds on a moonlit night.

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The Subaru Telescope illuminated by moonlight. A 3
meter long, 3 ton digital camera, Hyper Suprime-Cam(HSC), is mounted at the top of the telescope structure(prime focus). The Subaru Telescope is the only 8–10
meter class telescope in the world capable of mounting
a camera at its prime focus with a wide field-of-view.
The large light gathering power and sharp image
resolution enabled by the 8.2 meter primary mirror
combined with HSC’s wide field-of-view make theSubaru Telescope unique in its capabilities. HSC’s fieldof-view is nine times the area of the full moon, allowing
us to photograph countless galaxies in each frame andinvestigate the nature of the mysterious dark matter.

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Subaru Telescope Science 01

A corner of deep space photographedby HSC on the Subaru Telescope. The
contour lines in the image indicate the
distribution of dark matter elucidatedby measuring the gravitational
lensing effect.

Subaru Telescope

Investigating the Mysteriesof Omnipresent Dark Matter and Dark Energy
The Universe is filled with a mysterious substanceknown as “dark matter”; and a mysterious energy
known as “dark energy” is accelerating the expansionof the Universe. It is necessary to unveil the nature ofdark matter and dark energy in order to understand theevolution and the physics of the Universe. One way
to do that is by using gravity. By using gravitational
lensing, a phenomenon where gravity causes light tocurve, we can investigate the distribution of dark matter.
With its ultra-wide-field-of-view observation capability,
the Subaru Telescope excels at these observations.
Boasting 870 million pixels, Hyper Suprime-Cam(HSC) can capture a great number of galaxies in each
picture. By precisely measuring the distortion in thegalaxy images we can elucidate the 3D distributionof dark matter. In addition, by using the Prime Focus

Spectrograph currently under development capable ofobserving approximately 2400 objects simultaneously
to accurately measure the distances to many galaxies,
we can obtain the 3D distribution of dark matter athigh precision. Then, by comparing the 3D dark matter
distribution to theoretical models of structure formationand the expansion of the Universe we can determine
the characteristics of dark
matter and dark energy.
The galaxy cluster Abell 1689
photographed by HSC on the
Subaru Telescope. The gravity of
the cluster bends the light frombackground galaxies, causing theimages of those galaxies to appear
stretched.

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Subaru
Telescope
Gallery

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The Subaru Telescope is located in the summit region of Maunakea at an altitude

Telescope has greatly advanced Japanese astronomy. As of the end of 2021, itof 4139 meters. It is one of the best sites in the world for astronomy with many

has contributed to an outstanding total of 2476 papers and 164 doctoral theses. It

clear nights and stable air flow. Maunakea hosts 13 telescopes from 11 countries,

also appears from time to time in textbooks and various media outlets, making it

one of the largest collections of leading-edge astronomy observation facilities in

one of the widely recognized symbols of Japanese science.

the world. Through 20 years of observations since its first light in 1999, the Subaru

08★01 Star forming region S106 IRS4
★02 The Subaru Telescope★03 The galaxy IOK-1 (red object in the center of the inset) discovered
13 billion light-years away
★04 The snowy summit area of Maunakea (the Subaru Telescope
enclosure is visible on the right)★05 Three planets (red circles) orbiting the star HR8799★06 Subaru Telescope Control Room
★07 Starburst galaxy M82★08 The snowcapped summit of Maunakea seen from Hilo Bay★09 Jupiter's stratosphere imaged in mid-infrared (NAOJ/ NASA JPLCaltech)★10 Protoplanetary disk of the young star AB Aurigae★11 Close-up image of M31 (the Andromeda Galaxy)★12 Wide Field Corrector of Hyper Suprime-Cam★13 The Subaru Telescope enclosure with the laser beam for adaptive
optics (photograph: Dr. Sebastian Egner, Subaru Telescope, NAOJ)★14 Galaxy Cluster “Stephan’s Quintet”

Subaru Telescope Science 02

Subaru Telescope

Unlocking the Mysteriesof Galaxy Formation and Evolution
The Subaru Telescope, with its ability tosurvey large expanses of space with its
ultra-wide-field-of-view, has vigorously
conducted efficient searches for very
distant objects. The Strategic Programusing Hyper Suprime-Cam (HSC) tophotograph 400,000 galaxies has been
completed and now researchers areprocessing and analyzing the hugeamount of data. This will provide vital
clues for understanding the growth ofgalaxies. The wavelengths of light fromthe distant Universe are stretched by
the expansion of space. Observing
infrared light, with wavelengths longer

than visible light, allows us to observe
more distant objects. Currently we areplanning a wide-field, high-resolution
infrared camera to be mounted on the
Subaru Telescope. With it, we expect todiscover many newborn galaxies in theearly Universe. Follow-up observationsof the discovered objects using ALMAor the Thirty Meter Telescope (TMT) will
elucidate when the first stars formed
and the effects the newborn stars hadon their surrounding environment,
helping to solve the mysteries of galaxy
formation.

The farthest observed galaxy protocluster,z66OD, located 12.97 billion light years
away, as o bse r ve d by H SC o n t heSubaru Telescope. The member galaxesof the protocluster are indicated byboxes. The Subaru Telescope's ultrawide field of view is useful for searchingfor unknown distant objects, which could
be lurking anywhere. HSC's unrivaled
capabilities make the Subaru Telescope
an impor tant instrument in world
astronomy for exploring deep space.

Upgrading to Super Subaru Telescopewith “Subaru Telescope 2.0.”
Launched in 2022, Subaru Telescope 2.0 will break new ground in astronomy with next generation facility instruments.

The wide-field multi-object spectrograph,
Prime Focus Spectrograph (PFS), ism ounte d at t he pr ime fo c us of t heSubaru Telescope Science 03

Subaru Telescope

Discovery of Earth-like Exo-Planets
Over 5000 exo -planets have beend i s c ove r e d t o d a t e . T h e S u b a r u
Telescope is also displaying its strength
through observations of those exoplanets. In 2013, making the best use of
the Subaru Telescope’s high sensitivity,
it directly imaged the dimmest planet atthat time. Among exo-planets, Earthlike planets are garnering attention.
Direct imaging of these comparatively
small planets is difficult for 8-meterclass telescopes. But by using highdispersion spectroscopic observations
they can discover small planets throughthe wobble induced in the host star by
the orbital motion of the planet. At theSubaru Telescope we have installeda near-infrared Doppler instrument
to accurately measure line-of-sightvelocities to pursue the search for
Earth-like exo-planets. The discovered
exo -planets will be obser ved with
the Thirty Meter Telescope (TMT) to
analyze the atmospheric composition,and enable us to search for signs oflife, advancing the field of astrobiology.
(Refer to page 25.)

Subaru Telescope. It can simultaneously
observe up to 2,394 objects across its
1.3 degree diameter field-of-view. (top)One of the spectrograph modules in thetelescope dome. (bottom) The Prime
Focus Instrument, together with theWide Field Corrector, mounted at theprime focus of the telescope.
The exo-planet GJ 504b (dot in upper
right) discovered by the Subaru Telescope.
The bright light of the central star has
been artificially concealed, but someof the light still leaks out. GJ 504b is
the dimmest, coolest exo-planet everobserved. It is a giant planet with a mass
3~5 times that of Jupiter.

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ALMA

Atacama Large Millimeter/submillimeter Array

A radio eye exploring
the origins of the Universeand life

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Located in the Atacama Desert, ALMA is one of the world’s
highest capability radio telescope arrays, achieved throughan international collaboration including NAOJ, North America,
Europe, and other partners. The 66 individual antennas
function together as a single giant radio telescope. Its radio
observations show us a face of the Universe impossible tosee with visible light.

The ALMA array is deployed in the dry Atacama Desert at analtitude of 5000 meters. ALMA uses a technique called “radio
interferometry” to connect multiple parabolic antennas together
to act as a single, giant radio telescope. The 66 antennas can be
deployed across a range of up to 16 kilometers, achieving the sameimage resolution as a 16 kilometer diameter telescope would. The
resolution is equivalent to 120000/20 vision in terms of eyesight,
which corresponds to being able to see a penny in Los Angels
from San Francisco. With this overwhelming resolution ALMA cancapture clear images of the sites of planet formation.
[photo: Clem & Adri Bacri-Normier (wingsforscience.com) / ESO]

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The many parabolic antennas of ALMA. Built to withstand the harsh sunlightand temperature fluctuations of the desert, the antennas were developed by
combining the technological know-how of the various partners.

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ALMA Science 01

The disk of dust surrounding the youngstar HL Tauri, which is less than 1 million
years old, photographed by ALMA. The
dark spaces between the rings are thought
to be areas lacking dust to emit radio
waves. Some researchers speculate that
here, planets are already forming, andthat their gravity is creating the gaps bysweeping up the dust.
Credit: ALMA (ESO/NAOJ/NRAO)

ALMA

Unlocking the Mysteries of Star and Planet Formation
Newborn stars and planets still in the process of forming
lurk in the night sky. The diffuse clouds of interstellar
gas and dust are the material for stars and planets.
These clouds gradually compact, and in their centersstars and planets are born. These newborn stars are
hidden inside the parent clouds, where they cannot be
observed with visible light. But radio waves can escapefrom the clouds of gas and dust. ALMA collects theseweak radio waves to unlock the mysteries of star andplanet formation.
Disks comprised of gas and dust revolve around youngstars, with ages between 100 thousand and 10 million
years. These protoplanetary disks are the sites of planet
formation. ALMA's high angular resolution has revealed

concentric ring structures in the disks, as well as diskswith spiral or crescent shaped dust distributions. By
starting to image the sites of planet formation in detail,we are coming to understand the formation mechanismof the various planetarysystems in the Universe,
including our own Solar
System.

The spiral shaped protoplanetary
disk around the young star Elias
2-27 photographed by ALMA.
Credit: B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO)

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ALMA
Gallery
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★01 A sunspot photographed by ALMA

★02 ALMA Trilateral Agreement Signing Ceremony★03 ALMA Morita Array★04 ALMA image of the gas around the star U Antliae★05 Close-up of the center of spiral galaxy M77★06 ALMA Control Room

★07 A 7-meter antenna being transported to the Array Operations Site
★08 The surface of the Jovian moon Europa★09 Dust disk around TW Hydrae★12★10 Vicuna★11 Twenty sites of planetary system formation captured by ALMA
★12 Sunyaev-Zel’dovich effect in galaxy cluster RXJ1347.5-1145★13 Spiral Galaxy M74

Credit: ★04 ALMA (ESO/NAOJ/NRAO)/F.Kerschbaum ★05 ALMA (ESO/NAOJ/
NRAO), Imanishi et al., NASA/ESA Hubble Space Telescope and A.van der

Hoeven ★08 ALMA (ESO/NAOJ/NRAO), S. Trumbo et al.; NRAO/AUI NSF,

S. Dagnello; NASA/ESA Hubble Space Telescope ★09 S. Andrews (Harvard-

Smithsonian CfA), ALMA (ESO/NAOJ/NRAO) ★11 ALMA (ESO/NAOJ/NRAO),

S. Andrews et al.; NRAO/AUI/NSF, S. Dagnello ★12 ALMA (ESO/NAOJ/NRAO),
Kitayama et al., NASA/ESA Hubble Space Telescope ★13 NRAO/AUI/NSF, B.

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Saxton: ALMA (ESO/NAOJ/NRAO); NASA/Hubble ★All other images are credit:
ALMA (ESO/NAOJ/NRAO)

ALMA is located in the Atacama Desert in northern Chile. The Atacama Desert is said

wide enough to array 66 antennas is needed. Started with the joint site survey by the

to be one of the driest locations in the world, combined with the 5000 meter altitude, it isinternational team of researchers from the early 1990s, currently 22 countries anda harsh place to construct a telescope array. Because the radio waves ALMA observes

regions are participating in the operation of ALMA, including Japan, Taiwan, and South(around 1 mm on the border between millimeter waves and submillimeter waves) are

Korea in East Asia; the United States and Canada in North America; the European

absorbed by water vapor, an extremely dry location is needed. In addition an area

Southern Observatory representing its Member States; and the host country of Chile.

ALMA

ALMA Science 02

Searching for the Building Blocks of Life in the Universe
ALMA can catch the radio waves emitted
by various materials floating in space.
Researchers are particularly interested
in organic molecules connected to theorigin of life. What kinds of molecules
are found at the sites of planet formation
around young stars? Can the organic
molecules that become the seeds of life,
for example amino acids, be found here?
ALMA has discovered complex organic
molecules and simple suger moleculesaround newborn stars, as well as

elucidating the distribution of alcohol
molecules in protoplanetary disks. If
chemical reactions continue for thetens-of-millions of years it takes planets
to form around young stars, whatcomplexity of molecules can appear?
Through comparison with the resultsfrom space exploration missions like
Hayabusa2 in the Solar System, theplanetary system we know best, ALMA
will elucidate the evolution of theingredients for life.

One Unparalleled Instrument
through Global Collaboration,
ALMA Completely Changes
our View of the Universe!

Searching for the Youngest Galaxies
formed after the Big Bang
The Universe contains hundreds ofbillions of galaxies like our home MilkyWay, each containing hundreds ofbillions of stars. When and how werethese galaxies formed? How did they
evolve? To solve this mystery we needto investigate distant galaxies over 10
billion light-years away; in other words,
over 10 billion years back in time.
ALMA detected oxygen in the galaxy
MACS1149-JD1 located 13.28 billion
light-years from Earth. At the time, thiswas the record for the most distant (andtherefore earliest) galaxy where oxygen

surrounding young stars and foundvarious organic molecules including
methanol and acetaldehyde. Studies oforganic molecules at the sites of planet
formation will yield important clues about
the origin of life.

ALMA receivers developed at NAOJ.
From left to right: Band 4 (millimeter wave,
125~163 GHz), Band 8 (submillimeter
wave, 385~500 GHz), Band 10 (terahertz,
787~950 GHz).
Credit: ALMA (ESO/NAOJ/NRAO)

ALMAALMA Science 03

ALMA observed the protoplanetary disks

had been detected. Oxygen didn’t exist
in the cosmos right after the Big Bang. It
was produced by the nuclear reactionsin the cores of stars and then scatteredthrough space when those stars died.
So if we can detect oxygen, it meansthat many stars must have alreadybeen born and died before that. From
this discovery we learned that active
star formation must have started about
250 million years after the Big Bang.
ALMA has peered back into the era ofgalaxy formation in the earliest stagesof the Universe.

The wavelengths of light reaching us
from the distant Universe, in other words
the early Universe, have been stretchedby the expansion of space. The oxygenin the galaxy MACS1149-JD1 emitted
infrared light; but by the time that lightreached Earth it had been stretchedto radio wavelengths, which can beobserved by ALMA. Examining how muchthe wavelengths have been stretchedallows us to accurately determine thedistance to celestial objects.
Credit: ALMA (ESO/NAOJ/NRAO),
NASA/ESA Hubble Space Telescope, W.
Zheng (JHU), M. Postman (STScI), the
CLASH Team, Hashimoto et al.

15Thirty Meter Telescope

TMT

An Eye Searching Planets
for Extraterrestrial LifeThe Thirty Meter Telescope (TMT) is an optical-infrared telescope
under construction in the summit region of Maunakea by acollaboration of five countries, Japan (represented by NAOJ),
the United States, Canada, China, and India. With its 30 meter
primary mirror, it will achieve high sensitivity and spatial resolution
hitherto unknown to humans in the optical-infrared domain andsearch exo-planets for signs of life.

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An Artist’s Impression of TMT when completed on Maunakea. With its 30 meter
diameter mirror, it will have over 10 times the light collecting power of the Subaru
Telescope. With the aid of adaptive optics, in infrared observations it will achieve
angular resolutions about 5 times better than the James Webb Space Telescope.

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A computer model of TMT when completed. Half of thedome has been removed to make the telescope visible.
The 30 meter diameter primary mirror is comprised of 492
hexagonal mirror segments. The telescope will weigh 2,600
tons. (Credit: M3 Engineering)TMT Science 01
A prototype for the primary-mirror segments
developed in Japan. Notice the distinctive
hexagonal shape. Japan began mass
production of the mirror blanks in 2013 andmirror grinding in 2015. When completed,the mirror surface will be coated with silver.

TMT
Searching for Planets with Earth-like Environments
in Pursuit of Signs of Life
Numerous planetary systems have now been found inspace, including ones resembling the Solar System,and ones harboring terrestrial planets. With 10 times
the light gathering power of the current 8-meter classtelescopes, TMT will undertake hitherto impossible
observations of exo-planet systems. The ultimate goal
is to find terrestrial planets in the habitable zone where
the conditions are right for life, and look for evidence
that life actually exists on them. Because terrestrial exoplanets are small and dim, existing telescopes can’t
image them directly. With its high sensitivity, TMT willcapture the first image of a terrestrial exo-planet andenable spectroscopic analysis of the light reflected fromthe planet’s surface.
For exo-planets with orbits at special angles to the
Earth, TMT will also be capable of spectroscopic
analysis of the atmosphere of the planet. TMT has theability to detect the characteristic colors of plants, aswell as oxygen and ozone produced by plants, andorganic molecules of biological origin. TMT will explore
the universality of life in the Universe as yet unknown tohumankind.

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TMT

TMT Science 02

Determining the Nature of the “First Objects”
Born in the Universe
A scene from a computer simulation
depicting the birth of the first stars in
the cosmos. Actually observing the lightfrom these stars is one of the importantscience objectives of TMT.
Credit: Naoki Yoshida

A special glass with an extremely low
thermal expansion rate is used for TMT's
primary mirror segments, which comprisepart of Japan's contribution. As of March
2022, 356 mirror blanks have been
produced.
Credit: NAOJ/OHARA

When and how were the first stars andgalaxies in the Universe formed? This is
one of the biggest questions in modern
astronomy. ALMA and other telescopes
have already found signs that theearliest stars formed in the first 200~300
million years after the Big Bang. But
they haven't been able to capture theactual light from those stars. TMT with
its impressive 30 meter aperture andhigh sensitivity aims to catch the lightradiated by those first stars.

The first stars in the Universe weredazzling bright. When they died insupernova explosions, they ejected
elements heavier than hydrogen andhelium into their surroundings. In theseways they have had large influenceson the following evolution of the
Universe. TMT will catch the light fromfirst-generation stars and accurately
determine when they formed as well
as how their radiation and supernova
explosions affected the evolution ofgalaxies and the Universe.

TMT’s Giant Eye will Pierce
the Deepest Mysteries of the Universe.

A simulation of what the center of M31
will look like when observed by TMT (top)compared with an actual observation by
the Hubble Space Telescope (bottom).
TMT will deliver over 10 times better
resolution than the Hubble Space
Telescope.
Credit: T. Do/Dunlap Institutes/IRISTMT

TMT Science 03

Directly Measuring Dark Energy’s Effecton the Expansion of the Universe
Recent observations have revealed
that the expansion of the Universeis accelerating. Dark energy is the
hypothesized energy acting as the“repulsive force” to explain thisaccelerating expansion. But its true
nature is totally unknown and one of thelargest mysteries in modern physics.
To solve the mysteries of dark energy
we need to measure how the expansionof the Universe has changed over timeand learn the characteristics of dark

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energy. By measuring the redshifts ofmany far away galaxies at different
distances at some interval, for example
10 years, we can accurately measure
how much the expansion of the Universe
has accelerated (or decelerated) overthat time. TMT’s high light collecting
power will enable these kinds of highaccuracy observations. We expect TMT
to provide clues to understanding thetrue nature of dark energy.

Construction of TMTFive countries, Japan, the United States, Canada, China, andIndia, are participating in the TMT project. In 2014, the TMTInternational Observatory (TIO) was established to manage
the construction. Japan, represented by NAOJ, is obligatedto contribute approximately 20 percent of the construction
expenditures. NAOJ is responsible for design and constructionof the telescope structure, production of all of the mirror
blanks (574 including spares), and polishing for a portion ofthem (175), as well as development of instruments to achieve
the highest sensitivity and spatial resolution developed
through international collaboration. Also, instruments with awide array of observational capabilities are under development
in cooperation with domestic and international universities andresearch institutes.

Subaru Telescope

The summit region of Maunakea in Hawai‘i with TMT (artist’s
rendering) and other large telescopes including the Subaru Telescope.
Because the weather in the summit region of Maunakea is stable, allowing sharp
images to be taken, large telescopes belonging to countries around the world haveclustered here. TMT is scheduled to be constructed about 1 kilometer from theSubaru Telescope, at an altitude of 4012 meters. Because this is approximately
1000 meters higher than proposed sites for other extremely large telescopes, theobserving conditions are superior, especially in infrared.

21Uniting the Power ofSubaru Telescope, ALMA, and TMT① The Search for Life
Detailed observations of the increasing numberof exo-planets and protoplanetary disks, andgoals for 21st century astronomy. Together the
Subaru Telescope, ALMA, and TMT form asearching for life in the Universe are the largest

winning team in the “search for life.”

Finding
Habitable Exo-Planets

SubaruTelescope

The Subaru Telescope searches for exo-planetswith masses similar to Earth through high precision
spectroscopy to detect the wobble in the hoststar induced by the orbital motion of the planet.
The host star moves in reaction to the planet’s orbital
motion. Planets can be detected indirectly via spectroscopic
observations of the Doppler effect produced in the light fromthe host star.

Finding
Building Blocks for Life

ALMA

ALMA devotes its energies to observationsof formation sites of planets as the cradles oflife, and searches for organic molecules which
provide the building blocks for life.
The protoplanetary disk around the young star TW Hydrae
photographed by ALMA. The radius of a gap near the central
star (inset zoom-in) is comparable to Earth’s orbit. ALMA
detects the radio waves from various molecules in this kind ofplanet formation site.★01

Finding Life Signs

TMT

TMT will target exo-planets discovered by the
Subaru Telescope for detailed investigationsof the planets’ atmospheres through very highaccuracy spectroscopic observations to try tofind signs of life. This combined with ALMA’s
findings about the materials for life found in
protoplanetary disks will bring us closer tounderstanding the origin of life in the Universe.
If oxygen or an organic compound is found throughspectroscopic observations of the atmospheres of exo-planets,
the odds are high that life exists there.
Credit:★01 S. Andrews (Harvard-Smithsonian CfA) , ALMA (ESO/NAOJ/NRAO) ★02 ALMA (ESO/NAOJ/NRAO), NASA/ESA Hubble Space Telescope, W. Zheng (JHU), M. Postman (STScI), the CLASH Team, Hashimoto et al.

❸ Unveiling the mysteries of Dark Matter and Dark Energy
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The Subaru Telescope, ALMA , and TMT eachboast world leading per formance in theirrespective fields. When their power is combinedon common science themes, their capabilities to
produce exciting discoveries and revolutionize

our understanding of the Universe become evenhigher. NAOJ will operate these three telescopes
organically and efficiently aiming for long term
goals. Here let’s examine three concrete examples
of collaboration themes.

② The Search for the First Stars
One of the biggest problems in modern astronomy
is peering into the farthest corners of space toin the earliest Universe. The combination of the
Subaru Telescope, ALMA, and TMT provides

determine the true nature of the first stars formed

positive momentum to achieve this goal.

Search forVery Distant Objects
By searching for very distant objects in survey
observations by the Subaru Telescope’s ultrawide-field-of-view Hyper Suprime-Cam, we canfind targets for detailed follow-up observations
using ALMA or TMT.
Countless galaxies in the distant Universe photographedby Hyper Suprime-Cam on the Subaru Telescope. The
Prime Focus Spectrograph currently under development will
accurately determine their distances.

Determining
Chemical Composition
ALMA conducts high sensitivity follow-up
observations of very distant object candidates
discovered by the Subaru Telescope, catchingradio waves emitted by the atoms containedin those objects to determine their chemicalcomposition. This provides clues about theevolution of the earliest galaxies in the Universe.
★03

ALMA false color image (green zoom-in inset) showing theoxygen in the galaxy MACS 1149-JD1 located 13.28 billion
light-years from Earth.★02

Finding the First Stars
TMT will conduct high sensitivity follow-up
observations of very distant object candidates
observed by the Subaru Telescope, detecting
the characteristic light emitted by helium atoms
to elucidate when the first generation of stars
formed and what their characteristics were.
A scene from a computer simulation depicting the birth of thefirst stars in the Universe. Verifying the results of theoreticalstudies of the first stars through observations is anotherimportant theme.★04★03 ESO/B. Tafreshi (twanight.org) ★04 Naoki Yoshida

Despite the fact that dark matter and dark energy play criticalroles in the formation of celestial objects and the accelerating
expansion of the Universe, their true natures remain a mystery.
The Subaru Telescope elucidates the 3D distribution of dark
matter over wide areas through observations of gravitational
lensing based on ultra-wide-field images. In contrast, ALMA
uses its high resolution to measure the rotation speeds ofindividual galaxies and determine the dark matter distribution

within a galaxy. By combining these we can determine thecharacteristics of dark matter spanning a wide scale from tensof thousands of light-years to billions of light-years. As for darkenergy, investigating the distribution of dark matter found by the
Subaru Telescope will elucidate the role of dark energy in the
expansion of the Universe. In contrast, TMT will provide clues
to the nature of dark energy by directly measuring the change inthe expansion rate of the Universe.

23Division of Science
NAOJ advances astronomy research utilizing leading-edge observational facilities like the Subaru
Telescope, ALMA, and TMT. The NAOJ Division of Science is the driving force behind that research.

The NAOJ Division of Science is a newresearch unit established in April 2019.
Since it is independent of other projects,
researchers in the Division of Sciencecan focus on their astronomy researchwithout needing to manage the telescope
operations.
Under the keywords “fusion of theory
and observation”, “multi-wavelength
astronomy”, and “multi-messenger
astronomy”, members of the Division of
Science conduct research to advancemodern astronomy based on theirown original ideas, unimpeded by the
traditional divisions between observation

OpticalIR
Neutrino

GW

Div. of
Sci.

Radio

TheoryA diagram of the Division of
Science's goal of unified astronomy
utilizing various techniques.

wavelengths or research methods. As partof these activities, we promote an organic
fusion between the multi-wavelength
observational facilities of NAOJ andsimulation research using supercomputers.
Other important missions include
contributing to plans for future NAOJ
activities based on a broad perspectiveon astronomy, and cultivating young
researchers through training programs
including postgraduate education. Throughthese efforts, we aim to attract young
researchers from both inside and outsideof Japan and make NAOJ a global hub for
astronomy research.

Examples Combining Theoretical and Observational Research

Searching for the Cosmic Origins of Gold and Rare-Earth Metals

Credit:MasaomiTanakaMeasuring the Size of Planetary Seeds

Credit: Kataoka et al.
(2015) ApJ 809.

Magnitude

Optical light
Near Infrared lightDays after the detection of the gravitational wave

The origin of gold and rare-earth metals in the Universe
had been a longstanding mystery, but we now know thatthey are produced in “neutron star mergers.” A neutronstar is the object that remains after a massive star finishes
its life in a supernova. Theoretical research and simulation
studies using NAOJ’s supercomputer “ATERUI” predicted
the explosion caused by a collision of two neutron stars(upper image) and the brightness variations expectedin the formation of heavy elements after the explosion.
Comparing these predictions to the brightness variations
observed by the Subaru Telescope and other telescopes(lower graph) revealed evidence that elements including
rare-earth metals were in-fact produced.

24

Credit: ALMA (ESO/
NAOJ/NRAO),
Kataoka et al.

The theoretical prediction of the polarization of radio
emission from a protoplanetary disk (upper image, blackbars indicate the direction of the polarization, image
color indicates the degree of polarized emission) andthe polarized radio emissions from the protoplanetary
disk around the young star HD142527 observed by
ALMA (lower image, white bars indicate the directionof the polarization, image color indicates the strengthof polarized emission). Comparing the polarization
orientations obtained from observations to theoreticalmodels allowed us to extract information about the sizesof the dust grains which become the material for planets.

Pursuing Multi-messenger Astronomy
Multi-messenger astronomy has started, using not only the optical, infrared, or radio waves observed by the Subaru
Telescope or ALMA, but also gravitational waves and other signals to reveal multiple facets of the Universe.
Until the first half of the 20th century, humanity'sobservations of the heavens were limited to visible light.
Entering the latter half of the century “multi-wavelength”
astronomy utilizing radio waves, X-rays, infrared, andultraviolet light revolutionized our understanding of the
Universe.
Now, additional information has been added by signals
other than electromagnetic waves, such as neutrino andgravitational waves. In 2017, the American LIGO detector

The photo of the gravitational wave source GW170817 taken by HSC on the
Subaru Telescope and a visualization of the gravitational waves produced bya neutron star merger (upper right inset).

captured the gravitational waves from the merger of two
neutron stars for the first time in history. Comparing thesubsequent optical observations conducted by the Subaru
Telescope and other telescopes to theoretical predictions
elucidated the origins of gold and rare-earth metals forthe first time, throwing open the gates of multi-messenger
astronomy. With the addition of the Large-scale Cryogenic
Gravitational Wave Telescope KAGRA, further leaps are
expected.

KAGRA's vacuum duct (right). In the heart of
KAGRA we find large-scale optical suspension
systems developed at NAOJ. The mirror is coveredby the red protective filter (center).

Collaboration with the Astrobiology CenterWe pursue close cooperation with the Astrobiology Center (ABC) established by NAOJ’s parent
organization NINS (National Institutes of Natural Sciences) as a new research institute.
The Astrobiology Center was established in 2015 toadvance interdisciplinary studies of exo-planets andany life that may be hiding out in the Universe. It is aunique research institution that only NINS could create
with its institutes encompassing both life sciences andastronomy. Fueled by recent major breakthroughs in
exo-planet observations, it specializes in astrobiology,
the scientific search for “life in the Universe.” ABCcultivates new research fields created from the fusionof various related fields such as astronomy andbiology; engages in the search for planets outside of
the Solar System and the search for life, both insideand outside of the Solar System; and develops the
instruments for those searches. Having establishedthe “study of life in the Universe” as an importantresearch goal, cooperation between NAOJ and ABC
will become increasingly important.

An example of oxygen-generating
photosynthetic life (marimo). Researchis continuing to determine how
photosynthetic life affects the planet's
atmosphere; what could be a “biosignature”; and how can we best use
TMT in this search?

The Infrared Doppler Instrument (IRD, rightphoto), a near infrared very high precision
spectrometer for the study of exo-planets,
developed through collaboration between the
Astrobiology Center, NAOJ, and universities
was mounted on the Subaru Telescope in
2018. A large-scale observing program isunderway. This project discovered its firstexo-planet in 2022. This planet orbits a starcooler than the Sun, and could conceivably
have liquid water on its surface.

25

Technology Development
With its capability to develop cutting-edge observational facilities and instrumentson its own, NAOJ provides strong support for leading edge research.

❶ Large Telescopes for Optical-Infrared and Radio
Starting with the Nobeyama 45-m Radio Telescope, followed by the
Subaru Telescope, and ALMA, NAOJ has a history of developing large
telescopes with world-leading performance. Based on this experience,
NAOJ is now developing the 30 meter optical-infrared telescope TMT.
TMT will control its giant 2600 ton telescope structure with a high precisionbetter than one-thousandth of a degree and capture images with aresolution of a few hundred-thousandths of a degree.

❷ High Accuracy Optical Space Telescope
In cooperation with industry, we developed a space telescope withhumanity's highest angular resolution for solar observations and had it
installed on JAXA ISAS’s “Hinode” satellite. In order to achieve diffraction
limited performance, we developed
advanced technologies including adesign which lets out unnecessary
sunlight, the primary mirror support
structure, low expansion materials,
and a tip-tilt mechanism to prevent
image deterioration due to minuteSolar Observing Satellite Hinodevibrations in the satellite.

❸ Optical and Radio Sensors
We develop high sensitivity detectors to observe the weak light and radio
waves from space. In cooperation with industry we developed a CCD witha thicker silicon layer,vastly increasing its sensitivity to red light. We theninstalled 116 of the CCDs in Hyper Suprime-Cam on the Subaru Telescope
and for the first time produced a wide-field 3D map of dark matter.

NAOJ Technology Patents
Because astronomy observations require techniques spanning a wide
range of light and radio wavelengths, we can expect new applications
improving the standard of living. NAOJ makes efforts to acquire patents
for new technologies developed here. Through those patents, we aim toincrease Japan’s presence in the competitive arena of astronomy andrelated fields while also generating patent revenue.

NAOJ has specialized cleanroom
equipment for developing superconducting devices and has realized
steady production of superconducting
components with world-leading
performance. Here, we produced
ALMA receivers including its highest
frequency band (950 GHz). There
are only a few facilities in the worldthat can produce these kinds ofsuperconducting devices and receiversystems.

❹ Adaptive Optics to Correct for AtmosphericDistortion

When we observe heavenly bodies
from the ground, fluctuations in Earth’s
atmosphere cause the image toblur. Adaptive Optics is a technology
which greatly improves the angularresolution of a ground-based telescopeby correcting for the atmosphericfluctuations. NAOJ developed theadaptive optics system for the Subaru
Telescope, successfully improving theangular resolution by a factor of 10
thus far, enabling the discovery of new
exo-planets. The same technology
can be used for observing the Earthfrom space, transmitting light signals
to space, ophthalmology, or observing
living cells under a microscope.

As of September 28, 2022.

Notable Patents
Adaptive Optics Systems and Optics Equipment, Patent No.
6394850 (patented in Japan and the United States)

Optical Transmission Systems and Transmission Methods,
Patent No. 5291143 (patented in Japan and the UnitedStates)A technique to transmit signals across long distances by injecting a wide
range of signal frequencies from low frequencies to terahertz frequencies
into optical fibers, achieving a signal stability better than one second over
300,000 years.

26

Images of the same star taken
without adaptive optics (above)
and with adaptive optics (below).

❺ Photonic Techniques

Patents held by NAOJ: 21 domestic, 11 overseas

A system for improving the accuracy of adaptive optics which compensate
for fluctuations in the atmosphere, also capable of correcting for the
distortion in images taken with microscopes to enable hitherto impossibly
sharp images, with possible applications in precision measurement and life
sciences.

Superconducting device for
A L M A’ s h i g h e s t f r e q u e n c yreceiver.

The photonic technique to produce
terahertz frequency radio waves froman optical laser.

We are developing the technology
to control laser light to produce
signals from low frequencies toterahertz frequencies, with theaim of improving radio telescopes.
By using photonic techniques tocombine optical and radio we havesuccessfully generated a stablereference signal up to the terahertzband.

In this way, NAOJ is developing a variety of technologies for use
in astronomy. We accumulate the knowhow to optimize the overallcapabilities of the observational facilities by combining these techniques.
There are no other examples of these kinds of activities at Japanese
research institutes.

Future Plans
NAOJ plans to maintain its strong leadership position in world astronomy. Together with the Japanese and worldwide
research communities, we will open new doors in astronomy and plan next generation observational instruments.

What mysteries of the cosmos is astronomy poised toanswer in the 2020s and 2030s? What role should theJapanese astronomy community play internationally?
NAOJ is crafting long term plans to greatly advancethe level of world astronomy based on a dialog with theastronomy communities inside and outside of Japan.
“Small Project” and “Study Group” activities areunderway at NAOJ to form the foundation for concrete
future plans.
“Small Projects” are projects which have alreadyentered the development phase, including the “JASMINE
Project”, “RISE Project”, “SOLAR-C Project” (referto page 29), the “Subaru Prime Focus Spectrograph

Project”, and “Subaru Ground Layer Adaptive Optics(GLAO) Project.”“Investigation Groups” are groups planning large
projects which will carry forward future astronomy orgroups considering participation in large international
projects. In April 2019, two Investigation Groups were
established; the ngVLA (Next Generation Very Large
Array) Group and the SKA1 (Square Kilometer Array1) Group. The ngVLA plan led by the United States
will create a large-scale centimeter/millimeter-wave
interferometer. SKA1, advancing through cooperation
with various countries, is constructing large-scale, lowfrequency interferometers in Australia and South Africa.

Subaru Prime Focus Spectrograph Project

Subaru Ground Layer Adaptive Optics (GLAO) Project

The PFS fiber module. Actuators align each optical fiber to a different celestial
object so that the light from many targets can be fed into the spectrograph at
one time.

We aim to develop a new spectrograph to be installed on
the Subaru Telescope. By utilizing the Subaru Telescope’s
superior light collecting power and wide field of view,
PFS (Prime Focus Spectrograph) will allow simultaneous
spectral observations of up to approximately 2400
celestial objects across a wide field of view of 1.3-degree
diameter. Capable of spectra across a broad wavelengthband from optical through near infrared, it can efficiently
measure the distances to distant galaxies and investigate
the state of galaxies at different eras. PFS is being
developed through international collaboration among 12
institutions from 7 countries and regions led by the Kavli
Institute for the Physics and Mathematics of the Universe,
the University of Tokyo. NAOJ is to play a major role in
the installation and operation of the instrument.

By directing four laser beams into the sky and making the upper atmosphereglow, wide-field adaptive optics create artificial stars (laser guide stars),
which enable us to measure and compensate for the blurring by Earth’s
atmosphere. (Conceptual Image)

We aim to carry out an extensive upgrade of the Subaru
Telescope to keep the telescope on the cutting edgeof astronomy. By using multiple laser guide stars andwavefront sensors, GLAO compensates for the blurring
effect of the atmosphere across wide areas of the sky
in real time and allows us to conduct observations with
unprecedented depth and field of view, and with an image
sharpness comparable to the Hubble Space Telescope.
As part of the upgrade process, a deformable secondary
mirror is to be installed on the Subaru Telescope. It will
provide a sharp field of view of up to 20 arcminutes indiameter and, in infrared observations, a resolution of
about 0.2 arcseconds.

27

Various Projects and Centers Supporting
NAOJ’s Extensive Astronomy Research
NAOJ has various projects and centers
to conduct and support
a wide range of astronomy research.

Gravitational Wave Science ProjectCenter for Computational Astrophysics (CfCA)

The KAGRA vacuum duct.

ATERUI II

Observations of the Universe through gravitational waves started
in 2015 with the first direct detection of gravitational waves fromthe merger of two black holes. Now many gravitational wave
events have been observed, and multi-messenger astronomy
in combination with conventional telescopes is actively
pursued. Together with ICRR, KEK, and other institutes, weare participating in the development and operation of thegravitational wave telescope K AGR A. K AGR A will makeimportant contributions to the International GravitationalWave Observatory Network. New technologies are also being
developed at the TAMA300 interferometer in NAOJ Mitaka
Campus, producing world-leading results in quantum optics.

We promote the use of computer systems for simulation
including ATERUI II; the world’s fastest supercomputer for
astrophysics (theoretical peak performance of 3 Pflops),
research and development for simulation technology; andastronomy research using simulations. Our objective is toreveal aspects of the Universe that cannot be observed byany telescope through calculations based on the laws ofphysics. The project office has made many contributions to
our understanding of the large-scale structure of the Universe,
and the formation and evolution of celestial objects. We
strive to provide more realistic simulations and address theunsolved mysteries of the Universe.

28Solar Science Observatory
Using the solar observing
satellite “HINODE,” the Solar
Flare Telescope in Mitaka,and the Nobeyama Radio
Polar imeters, we obtain,
compile, and publish themulti -wavelength data of
The Solar Flare Telescope (left) and Solarsolar magnetic activity. By
Observing satellite “HINODE” (right)
observing the 3D structure
and time evolution of the magnetic field from the solar surface
to the upper solar atmosphere, research is progressing on
dynamic activity such as jets and waves that heat the solar
atmosphere as well as both the effects of sudden explosions
in the inner heliosphere and their origins. Also, cutting-edge
research and rocket and balloon experiments are conducted
for the development of next generation ground and spacebased solar observing instruments.

JASMINE Project
The JASMINE Projectworks to realize thesatellite “JASMINE” toreveal the Milky Way’s
central core structureand formation history bymeasuring the distances
and the motions of stars
JASMINEthrough high-precision
positional astronomy in
the infrared and to explore the evolution history of the MilkyWay. The satellite also aims to search for Earth-like habitable
exoplanets by detecting the dimming when a planet transits infront of a red dwarf star smaller than the Sun. JASMINE has
been selected as the JAXA-ISAS Competitive Middle-Class
Science Missions No.3.

SOLAR-C Project
The hot chromosphere andcorona above the solar
surface are awash with finejets and waves driven by themagnetic f ield. The nex tgeneration satellite SOLAR-C
can simultaneously observe
all temperature ranges,
from 20,000 degrees at theSolar-C Credit: NAOJ/JAXA
chromosphere to the over 2
million degree temperaturesthat appear in the corona during a flare, and will carry ourunderstanding of solar magnetic energy release regions intoa domain beyond the reach of the current solar observing
satellite “HINODE.” SOLAR-C development, led by Japan with
contributions from Europe and America, continues, aiming for alaunch in the late 2020’s.

RISE Project
Investigating the interior structureof Solar System bodies reveals
their origins and evolution. In
JAXA’s lunar explorer “KAGUYA,”the RISE Project measured
the Moon’s shape, investigated
the gravitational field on the far
side of the Moon precisely, andrevealed the topography of the
The shape of Ryugu observed by the
Hayabusa2 laser altimeter. ★
lunar surface, including the polar
regions. Recently, it has developed a laser altimeter for theAsteroid Explorer Hayabusa2 with collaborators, and oversaw
it’s operation and science observations. For future missions,
RISE is leading international collaboration to develop the
Ganymede laser altimeter for the European Jovian moons
explorer and heading a sub science team for the JapaneseMartian moons explorer.
★ Credit: NAOJ, JAXA, Chiba Institute of Technology,
the University of Aizu, Nihon University, Osaka University.

29

Mizusawa VLBI Observatory

Astronomy Data Center

VER A of Mizusawa VLBI
Obser vator y is a project
combining four 20-m radio
telescopes located at
Mizusawa, Iriki, Ogasawara,
and Ishigakijima to create ahuge virtual radio telescopewith a diameter of 2300 km.
The 20-m radio telescope at Mizusawa VLBI.
VERA maps our Milky Way
galaxy by measuring the distances to celestial objects withhigh accuracy. Aiming to improve the performance by adding
radio telescopes, we promote international collaborations
mainly with observatories in East Asia. We have built KaVA,
a network combining VERA and three KVN radio telescopes
located in South Korea, and we are establishing the East Asia
VLBI Network by adding antennas in China.

The Astronomy Data
Center provides
comprehensive
services related tothe collection anddisclosure of datacollected by NAOJ
and other domestic
and overseas
Computer array for astrophysical calculations.
facilities. In addition
to developing theanalysis software for Hyper Suprime-Cam, we operate theJapanese Virtual Observatory (JVO) through which anyone
can access observational data obtained by the Subaru
Telescope and ALMA to promote database astronomy.

Nobeyama Radio Observatory

Advanced Technology Center

The 45-m telescopeat Nobeyama Radio
Obser vator y pion e e r e d m i l l i m e t e rwave astronomy inJapan. Utilizing its
high sensitivity, weobserve radio waves
emitted from various
The Nobeyama 45-m Radio Telescope.
interstellar molecules.
We have especially
focused on detailed observations of molecular gas clouds instar-forming regions and investigations of unusual molecular
clouds near the center of the Milky Way. One of the fruits ofour research is a completed catalog showing the evolution of
the Orion molecular cloud complex.

The development of new
observation instruments
has stimulated advances
i n a s t r o n o my. T h e
Advanced Technology
Center is a base for thedevelopment of advanced
instrumentation for
astronomy in wide
Subaru Telescope’s HSC being test-assembled inranges of wavelengths,
the laboratory.
both ground-based andspace-based. We have developed Hyper Suprime- Cam (HSC)
for the Subaru Telescope, receivers for ALMA, a visible-lighttelescope and an X-ray telescope for Hinode, and optical
instruments for KAGRA. We also develop next-generation
instruments including instruments for TMT and new receivers
for ALMA.

ASTE Project

Public Relations Center

The ASTE telescope (Atacama
Submillimeter Telescope Experiment)
is a 10 -m diameter submillimetertelescope established in the Atacama
Desert (altitude 4860 m) in Chile in2002. Taking advantage of the widearea, broad-waveband capabilities
provided by a large-aperture, singled i s h s u b m i l l i m e t e r t e l e s c o p e, i t
10-m submillimeter antenna
provides a platform for advanced
research and development and pilot observations leading
to future observations with ALMA. It conducts wide-field,
submillimeter observations of molecular clouds in the Milky
Way and nearby galaxies using the 490 and 810 GHz bandreceivers, and observational research on distant galaxies
using the world’s first on-chip superconducting spectrometer.

We are committed to disseminating the latest f indings
in astronomy, publishing new
astronomical object reports andthe Ephemeris, and supporting
the activity of the IAU Officefor Astronomy Outreach. In
addition, we play a major rolein science communication
activities for astronomy
outreach through collaboration
with public obser vatories,
museums, and planetariums. Regular Stargazing Party using the 50We also operate the N AOJ cm Telescope.
Library which houses a number of valuable books related toastronomy.

30

Organization
The Project System clarifies the activities and plansof NAOJ in terms of projects, centers, and divisions,each with specific goals and timelines. The Project
System advances the sharing of resources throughout
the entire observatory; defines the responsibilities andcapabilities of project leaders and staff; and improves
the clarity and independence of research.

Projects

C Projects
Mizusawa VLBI (Very Long Baseline
Interferometry) Observatory

SKA1 Group

Nobeyama Radio Observatory
Solar Science Observatory
Subaru Telescope

Okayama Branch Office

Center for Computational Astrophysics
NAOJ ChilengLVA Group

ALMA Project
Advisory Committee for Research and Management
Director General
Vice-Director General (on General Affairs)

B Projects
Gravitational Wave Science Project

Kamioka Branch Office

TMT (Thirty Meter Telescope) Project Office

California Office

A Projects

Vice-Director General (on Finance)
Director of Engineering

JASMINE (Japan Astrometry Satellite Mission for INfrared Exploration)
Project

Director of Research Coordination

RISE (Research of Interior Structure and Evolution of Solar System Bodies)
Project

Executive Advisors to the Director General

SOLAR-C Project
ASTE Project3 Groups of Projects and 3 Centers

Subaru Prime Focus Spectrograph (PFS) project
Subaru Ground Layer Adaptive Optics (GLAO) projectAt NAOJ, projects are divided into 3 groups based on their roles.
C Projects group - the seven projects such as Subaru Telescope,

ALMA, the Supercomputer “ATERUI II,” Solar Observing Satellite
HINODE, etc., which have been completed as NAOJ facilities and areoperating. This project group is the main driving force of NAOJ, actively
supporting leading edge observations and research.

B Projects group - two project offices that are under construction
or being developed. The TMT Project is constructing the 30 metertelescope TMT. The Gravitational Wave Science Project is undertaking
gravitational wave observations using K AGRA, the Large-scale
Cryogenic Gravitational Wave Telescope.

A Projects group - projects pursuing small-scale development
plans. In April 2019, the “Subaru Prime Focus Spectrograph Project”
and the “Subaru Ground Layer Adaptive Optics Project” were added tothe already existing “JASMINE Project”, “RISE Project”, and “Solar-C
Project.”“Investigation Groups” are established to investigate observational
instrument development plans closely related to NAOJ’s future strategy.
Currently the ngVLA Group and SKA1 Group are active.
An additional two, the OISTER Network of optical-infrared telescopes inJapan and Japanese VLBI Network are being pursued in cooperation withJapanese universities.

The three centers extend across the framework of individual
projects and play key roles in equipment development,
technological research, data analysis, data archiving, and public
outreach activities. The centers provide the basic infrastructure of
NAOJ.

Centers
Astronomy Data Center
Advanced Technology Center
Public Relations Center

Division of Science

Collaborative
Projects

Inter-university Collaboration: Opticaland Infrared Synergetic Telescopes for
Education and Research (OISTER)
Inter-university Collaboration:
Japanese VLBI Network (JVN)

Administration Department
General Affairs Division Research Promotion Division
Financial Affairs Division Accounting Division
Facilities Division
Library
IT Security Office
Research Enhancement Strategy Office
Research Evaluation Support Office
Industry Liaison Office
Office of International Relations
Human Resources Planning Office
Safety and Health Management Office
Engineering Promotion Office
Graduate Education Office31

NAOJ Facilities
Our research facilies have been set up
throughout Japan and around the world in thebest observaonal environments to explore
the Universe.

NAOJ Mizusawa

Mizusawa VLBI Observatory (VERA)NAOJ Mizusawa has a long history since its founding as a part of the Internaonal Latude Observatories. It operates VERA to observe the MilkyWay, black holes, etc.
Center for Computational Astrophysics
NAOJ Mizusawa hosts ATERUI II, the world’s
fastest supercomputer dedicated to astronomy.
RISE Project
The RISE Project has contributed to instrument
development, observaon operaons, and spacecra orbit esmaon for KAGUYA and Hayabusa2,
and has been carrying out research and development for exploraon of the satellites of Mars andJupiter.

Japanese Branches

VERA Mizusawa Station

ATERUI IINAOJ Nobeyama

Nobeyama Radio Observatory
Nobeyama Radio Observatory raised Japaneseradio astronomy to the top er interna onally.
The 45-m Radio Telescope is one of the largest
millimeter radio telescopes in the world. It has
achieved epoch-making results, such as discovery of new interstellar molecules and detec onof the signature of a supermassive black hole ina galaxy. Nobeyama Campus is open daily to the
public.

GWSP Kamioka Branch,
KAGRA
KAGRA, a gravitaonal wave telescope constructedin the Kamioka Mine, aims to expand the field ofgravitaonal wave astronomy. The Kamioka
Branch of the Gravitaonal Wave Science Project supports the installaon and commissioningof KAGRA.

Subaru Telescope
Okayama Branch

Mizusawa

Open-use observa ons are conducted by NAOJ at the
3.8-m telescope of the Okayama Observatory, theAstronomical Observatory of the Graduate School of
Science, Kyoto University. Open-use observing opportuni es with the largest op cal and near-infrared
astronomy facility in Japan are provided.

Mizusawa VLBI
Observatory :Ibaraki Station

IbarakiMizusawa VLBI
Observatory :Yamaguchi Station

Kamioka

Nobeyama
MitakaOkayama

NAOJ Mitaka

As the headquarters of
NAOJ, Mitaka Campus
h o u s e s o ffi c e s o fvarious projects anddivisions, as well as
administrave offices.

Yamaguchi

Mizusawa VLBI Observatory :Ishigaki-jima Station (VERA)
Iriki
Ishigakijima Astronomical
Observatory
MURIKABUSHI is a 105-cm
telescope in Ishigakijima
Astronomical Observatory.

Mizusawa VLBI Observatory :Iriki Station (VERA)

32

Ishigaki Island
MURIKABUSHI

Chichijima,Ogasawara Islands

Mizusawa VLBI Observatory :Ogasawara Station (VERA)Overseas Branches
NAOJ Hawaiʻi

Subaru Telescope, NAOJ TMT Project

The Islandof HawaiʻiWith many clear nights and stable airflow, the summit region of
Maunakea (4200 meter altude) is well suited for astronomy observaons. Here, NAOJ constructed and operates the Subaru Telescope, andthe 30 meter opcal-infrared telescope TMT is being constructed
through internaonal collaboraon.

Maunakea

Hilo

Hilo Base Facility
The base facility of Subaru Telescope is located in
Hilo on the Island of Hawaiʻi. As the base for theunified operaon of the Subaru Telescope and
TMT, this facility has laboratories, a machine shop,
computer room, a remote observaon room, etc.

The Subaru Telescope (left)
An opcal-infrared telescope with a world-class 8.2 meter
aperture. Full-scale observaons started from FY 2000. In FY
2022, a new project called “Subaru Telescope 2.0” started toinvesgate the evoluon of the Universe and the origin ofelements with new core instruments.

TMT (right)
An extremely large opcal-infrared telescope being
constructed through internaonal collaboraon between
Japan, the United States, Canada, China, and India. With
more than 10 mes the light collecng power of the Subaru
Telescope, it aims to discover signs of life in the atmospheresof exo-planets and capture the light from the earliest stars in
the Universe.

NAOJ Chile
NAOJ Chile, NAOJ ALMA Project
The Atacama Desert in northern Chile, one of the driest
places on Earth, is an ideal locaon for short wavelength
radio wave (millimeter and submillimeter wave) observaon. ALMA and ASTE have been established here. The
NAOJ Chile office and the Joint ALMA Observatory Sanago
Central Offices are located in Sanago, the capital of Chile.

ALMA
ALMA, led by NAOJ, the Naonal Radio Astronomy Observatory (US), and the European Southern
Observatory, is a giant radio telescope array with 66 antennas operated on a 5000 meter elevaonplateau in Chile. NAOJ collaborates in East Asia with the Academia Sinica Instute of Astronomy andAstrophysics in Taiwan and the Korea Astronomy and Space Science Instute.
Credit: ESO
ASTE
ASTE observes submillimeter radio waves withwavelengths shorter than 1 millimeter. Establishedin the Atacama Desert with opmal condions for
submillimeter astronomy, it applies its strength toobservaons of the southern sky including the
Galacc center region, nearby star-forming
regions, and distant galaxies.

ALMA

Public Access to NAOJ facilities

Santiago
ALMA Operations Support Facility
The Operaons Support Facility is located 30 kilometers awayfrom the ALMA Array Operaons Site. It serves as the "basecamp" for ALMA with lodgings and a cafeteria for ALMA staff inaddion to the control room for remote operaon of ALMA
and laboratories where instrument maintenance is performed.
Credit: ESO

To widely disseminate our research results tothe public, the major facilities of NAOJ offer
visitors' areas, annual open house days, or
regular stargazing parties.

33

Top Level Researchwith NAOJ Facilities
NAOJ develops and operates large-scale research
fac ilities that would be dif f icult for individual
universities to maintain. By sharing these facilities
with researchers from universities in Japan, NAOJ
provides cutting-edge research environments tothem. In addition to sharing facilities, NAOJ provides
extensive user support to cultivate young researchers;
helps individual researchers improve the quality of
their research; promotes interdisciplinary research;and conducts collaborative research with researchersin Japan and abroad. We also give back to thecommunity through activities to support university
researchers and raise Japan’s international profile
including the compilation and publication of various
astronomy data and open-use analysis environments
by the Astronomy Data Center; collaborative research
and facility use in the Advanced Technology Center;and the dissemination of research results in Japanand overseas by the Public Relations Center.

Selected Resultsfrom the Subaru Telescope
Discovery of manysupermassive black holes
13 billion light-years away.

A supermassive black hole (red dot indicated by
the arrow) located 13.05 billion light-years away.

A research team led by Yoshiki
Matsuoka of Ehime University used
Hyper Suprime-Cam (HSC) mounted
o n t h e S u b a r u Te l e s c o p e a n d
discovered 83 supermassive black
holes 13 billion light-years away. The
study showed that a large number ofsupermassive black holes alreadyexisted in the very early phase of the
Universe.

Hot gas from galaxy
cluster collisions revealed
by multi-wavelength
observations.
A team led by Nobuhiro Okabe of
Hiroshima University combined
Subaru Telescope visible lightobser vations with X-ray andradio data to conduct a detailed
investigation of turbulence in galaxy
clusters, and found that cluster
collisions heat the surrounding gas
to more than 400 million degrees.

Composite image of galaxy cluster XLSSC 105.
The distributions of dark matter (blue), X-rays(green), and radio waves (red) are overlaid on a
Subaru Telescope image of the individual galaxies.
Credit: GBT/NSF/NAOJ/HSC-SSP/ESA/
XMM-Newton/XXL survey consortium

Little lithium produced inclassical nova

We regularly hold Users’ Meetings, in which we share the present state of ourtelescopes and their future plans to discuss how to yield better results

A team led by Akira Arai at Kyoto
Sangyo University used the Subaru
Telescope to investigate beryllium,
the precursor of lithium, in classicalConceptual image of lithium production in nova
nova V5 6 6 9 Sgr to investigate
V5669 Sgr.
production sites of lithium. The
Credit: Kyoto Sangyo University
amount of lithium produced in thisclassical nova is only a few precent of that seen in others, indicating a rangeof lithium production in classical novae.

Integrating NAOJ’s
Technologies into Society

34

A iming to ac hieve new break throughs inastronomy, NAOJ has developed and refined
its own technologies to create its world-leading
obser ving facilities. The “ technologies for

A CCD Camera for Spaceguard

Megapixel CCD with High IR Sensitivity

Based on the technology used in HSC
mounted on the Subaru Telescope,
NAOJ developed a CCD camera for the
1-m telescope at the Bisei Spaceguard
Center in cooperation with the Japan
Aerospace Exploration Agency and theJapan Space Forum. This camera has
been used to find and track asteroids
and space debris for 10 years and, by
ensuring the safe operation of satellites,
contributed to making our society moresecure.

In collaboration with Hamamatsu
Photonics K.K., NAOJ developed a CCD
with a 200-μm-thick depletion layer,
dramatically improving the infraredsensitivity. As this sensor has a high
X-ray sensitivity as well, it was also used
in JAXA’s Hitomi satellite. The same typeof sensor is used in transmission electron
microscopes (TEM). Its high sensitivity
in X-ray is also valuable in medicine andcan lighten the burden on patients by
reducing the dose of X-rays required.

A CCD camera mounted on the telescope fortracking space debris.
Credit: JAXA

A newly developed megapixel CCD (2048
× 4096 pixels and 30 mm × 60 mm lightreceiving surface).

Selected Resultsfrom ALMA

Published Papers
Statistics

Oxygen in galaxies morethan 13 billion light-years
away
A research team led by Akio Inoueat Osaka Sangyo University used
ALMA to detect oxygen in a distantgala x y 13.1 billion light-year saway, and then in a more distantone 13.28 billion light-years away.
With these discoveries, the record
for the most distant galaxy withoxygen was broken twice. These
results made great impacts on
the worldwide galaxy formation
research community.

False color image of MACS1149-JD1, a galaxy
located 13.28 billion light-years away. The oxygen
distribution is shown in green.
Credit: ALMA (ESO/NAOJ/NRAO), NASA/ ESA
Hubble Space Telescope, W. Zheng (JHU), M.
Postman (STScI), the CLASH Team, Hashimoto et al.

Most ancient galaxy withobserved spirals
A team led by Takafumi Tsukui, agraduate student at SO K EN DA I,
found a galaxy with spiral morphology
from ALMA data for 12.4 billion years
ago. The discovery of a spiral galaxy
only 1.4 billion years after the Big
Bang could help answer longstanding
questions in astronomy about how the
shape of a galaxy is determined.

Papers authored/coauthored by NAOJ
researchers
Papers authored byopen-use users

The number of papers published by
NAOJ researchers has been increasing
in tandem with the progression of thelarge projects. Through the openuse program, papers published byresearchers affiliated with universities
are also increasing.
Percentage of the top 10 % most cited
papers written by NAOJ researchers:
16.2 % Percentage of the top 1 %most cited papers written by NAOJ
researchers: 2.5 % Percentage ofinternational coauthorship: 79.6 %(2017 ~ 2021 Averages)

As of September 26, 2022.

Operation of Okayama 188-cm
Telescope and the Seimei telescope

BRI 1335-0417, a galaxy with spirals
12.4 billion years ago observed by
ALMA.
Credit: ALMA (ESO/NAOJ/NRAO), T.
Tsukui & S. Iguchi

Organic molecules at theedge of the Galaxy
A team led by associate professor
Ta k a s h i S h i m o n i s h i a t N i i g a t a
University observed the edge of the
Milky Way Galaxy with ALMA andfound chemically-rich molecular gas
Conceptual image of organic molecules aroundincluding complex organic molecules
a protostar in the extreme outer Galaxy.
around a newborn star. The ancient
Credit: Niigata University
environment is preser ved in theextreme outer Galaxy, indicating that organic molecules can be formed
efficiently even in the primordial environment.

The Subaru Telescope Okayama Branch Office has provided opportunities
for observations using the Okayama 188-cm Reflector Telescope andthe HIgh Dispersion Echelle Spectrograph (HIDES) for almost 20 years,
and contributed to the development of research on exo-planets in Japan,
including Japan's first detection of an exo-planet. At present, NAOJ is
responsible for the open-use operation of the 3.8-m “Seimei” telescope of
Kyoto University.

Collaboration with Universities
NAOJ operates observation facilities in collaboration with universities
and institutions both in Japan and abroad.
The Optical and Infrared Astronomy Research and Education Network(OISTER) aims to conduct immediate follow-up observations of transient
astronomical phenomena, such as supernovae, by organically connecting
mid-to-small-size telescopes.
The Japanese VLBI Network combines radio telescopes operated by NAOJ
and domestic universities to create a giant virtual radio telescope, throughwhich we study the dynamics of gas in star-forming regions and gas jets
blasting out from black holes.

astronomy” that we have developed in the process can be
repurposed to benefit our lives and society. We intend toutilize the technologies for astronomy to make our society
more secure, convenient, and healthy.

Earth-observing Instrument
onboard the International Space Station
The Superconducting Submillimeter-Wave
Limb-Emission Sounder (SMILES) was anobservational instrument installed on theInternational Space Station. Its mission was
to detect the radio waves emitted by trace
molecules in the Earth’s atmosphere andreveal the fluctuations in their distributions.
NAOJ played a major role in the developmentof the sub -millimeter wave (640 GHz)
receiver installed on the instrument.

↑
SMILES installed on the Japanese Kibo
module. Credit: NASA

Leading Astronomy Outreach
Initiatives Globally
The International Astronomical Union (IAU) Office for
Astronomy Outreach (OAO) is the IAU’s international
office for outreach located at NAOJ Mataka Campus, inTokyo. The OAO is a joint venture between the IAU, thelargest association of professional astronomers in theworld, and NAOJ. It’s responsible for leading the IAU’s
global communications and accessibility initiatives and forsupporting the international network of National Outreach
Coordinators (NOCs) located in more than 100 countries.
This successful collaboration is one of the many initiatives
for internationalization and diversity at NAOJ.

35

NAOJ makes an effort to educate graduate students who will become
leaders in the next generation. Through international education andresearch in cutting-edge research facilities, we aim to develop not only
world-leading researchers and innovative engineers but also individuals
who are able to contribute to wider society.

Graduate Course
Education

NAOJ accepts graduate students through the following
three programs.
❶ The Graduate University for Advanced Studies(SOKENDAI)SOKENDAI is a graduate university based on world classresearch institutions including NAOJ.

Number of Graduate Students (as of April 1, 2022)
Students from SOKENDAI (five-year doctoral course) ......32
Students from cooperative graduate schools......28
Visiting graduate students......14
NAOJ accepted students from the following graduate schools
in the last five years.
Tohoku University, Ibaraki University, University of Tsukuba, The University of❷ Cooperative Graduate School Program

Tokyo, Tokyo Institute of Technology, University of Electro-Communications,
Niigata University, Shinshu University, Nagoya University, Yamaguchi University,
Kyushu University, Kagoshima University, Osaka Prefecture University, Kyoto
Sangyo University, Tokyo City University, Nihon University, Japan Women's
University, Hosei University, Tufts University (in no particular order)❸ Visiting Graduate Students Program

Profile of NAOJ
■ Budget (FY 2021)

EngineeringStaﬀ 9038.0 ％

Administrative Staﬀ
(including Research
Support) 196

Total 516

4 4.6%■ Number of Employee (as of April 1, 2022)
ResearchandAcademic
Staﬀ 230■Industry-Academia Research■Industry-Academia Research

Income and Donation Income:
465■Miscellaneous Income: 28■Subsidy Income:
1,535■Facilities Maintenance

1 7.4 ％

Unit: 1 million yen

Grants: 1,444

Expenses and Donation
Expenses: 465

Total
Revenues:
13,434■Management Expenses
Grants: 9,962■Subsidy Expenses:
1,535■Facilities MaintenanceExpenses: 1,444

Total
Expenses:
13,434■Management Expenses:
9,962

History of NAOJ
Tradition and Innovation:
playing a part in Japan's natural science research
The origin of NAOJ dates back to the late Edo Era (more than 300 years ago) when the
Shogunate Tenmonkata started observations of celestial objects to create ephemerides.
NAOJ still carries on the compilation of ephemerides as a part of its duties. The Meiji Era
saw the inflow of knowledge about modern astronomy from the West, and as a result, theTokyo Astronomical Observatory and the Latitude Observatory were established in 1888
and 1899 respectively. Thereafter, Japanese astronomers developed various observing
instruments and conducted much research over the next 100 years. Then, in 1988, the Tokyo
Astronomical Observatory of the University of Tokyo, the Latitude Observatory, and a partof the Nagoya University Research Institute of Atmospherics were integrated to establish
NAOJ. Let’s briefly look back on the history of NAOJ which has always been a pioneer at theleading-edge of astronomy research.

The Astronomical Observatory in Asakusa in the Edo Era (From Treatiseon the Kansei Calendar).

36

Kansei Calendar enacted in 1798, Kansei Era 10.

Tenmon Bun’ya No Zu: Chart of the Constellations and the Regions they Govern
published by Harumi Shibukawa (the first
Shogunate Tenmonkata, also known as Yasui
Santetsu) in 1677, Enpō Era 5.

Latitude Observatory

1888

T h e To k yo A st r o n o m i c a l O b s e r vat o r y wasestablished. (Iikura, Azabu)

1899

The Latitude Observatory was established in
Mizusawa.

1924

The Mitaka campus was started to establish.

1925

Publication of “Chronological Scientific Tables (Rika
Nenpyo)“ began.

Rika Nenpyo
Since its first publication in 1925, wehave been publishing Rika Nenpyo foralmost 100 years in cooperation withmany other research organizations.
Also available in English.
https://official.rikanenpyo.jp/
posts/5905

Mitaka Campus in the earlyShowa Era

65-cm Refractor Telescope

1926

65-cm Telescope Dome completed.

1929

65-cm equatorial telescope was equipped.

1930

Solar Tower Telescope (The Einstein Tower) was
built.
Publication of Almanacs and “Calendar and Ephemeris“ began.
Norikura Solar Observatory began observations.

1946
1949

1962

Okayama Astrophysical Observatory began observations.
Dodaira Observatory began observations.

1969

Nobeyama Solar Observatory began observations.

1982

1992

Nobeyama 45-m Radio Telescope began observations.
The National Astronomical Observatory of Japan wasestablished.
Nobeyama Radioheliograph began observations.

1999

Subaru Telescope first light.

1960

1988

Solar Tower Telescope

Laser Interferometer Gravitational Wave Antenna“TAMA300“ began observations.
2000 Dodaira Observatory was closed.
1999

2000 Visitors’ Area opened at Mitaka Campus.
Laser Interferometer
Gravitational Wave
Antenna (TAMA300)

Mizusawa 20-m Radio Telescope

2001
2001

Agreement of ALMA project among Europe, theUnited States, and Japan.
VERA Stations began observations.

2004 NAOJ was incorporated as the National Astronomical
Observatory of Japan, National Institutes of Natural
Sciences, Inter-University Research InstituteCorporation.
2006 Ishigakijima Astronomical Observatory beganobservations.
2006 HINODE began solar observations.

2011

As a part of the Four-Dimensional Digital Universe(4D2U) project, the 3-dimensional dome theater wascompleted.
The Lunar Explore “KAGUYA” was launched andbegan observations.
Norikura Solar Observatory was closed after 60
years of service.
ALMA Early Science operation started.

2013

Regular ALMA observations started.

2014
2015

TMT International Observatory was established.
NAOJ participated as an initial member.
Nobeyama Solar Observatory was closed.

2018

Okayama Astrophysical Observatory was closed.

2018

Super Computer ATERUI II started operation.

2020

KAGRA began observations.

2007

2007
2010
ALMA

Nobeyama 45-m Radio Telescope
Subaru Telescope

37

NAOJ: Pioneering
the Future of Astronomy
There are three main themes in 21st-century astronomy: the search for extraterrestrial life;
understanding the beginning of the Universe; and understanding the nature of dark matter anddark energy. At present, major countries around the world are racing to construct large observing
facilities to tackle these subjects. In this era of international cooperation and competition, theNational Astronomical Observatory of Japan (NAOJ) actively conducts scientific research basedon the following three mission statements: developing and constructing large- scale cutting-edge
astronomical research facilities and promoting their open access aiming to expand our intellectual
horizons; contributing to the development of astronomy as a world leading research institute bymaking the best use of a wide variety of large-scale facilities; and bringing benefits to society throughastronomy public outreach.
Modern Japanese astronomy began when Harumi Shibukawa (Santetsu Yasui) completed an original
calendar, the Yamato-reki (also called Jokyo-reki), in 1684. The earliest forerunner of NAOJ was the
Astronomical Observatory in Asakusa of the Tenmonkata (Shogunate Astronomer) established in thelate Edo Era. In 1888, the Astronomical Phenomenon Observatory of the University of Tokyo, Navy
Meteorological Observatory, and the Geographical Bureau of the Home Ministry were integrated
to form Tokyo Astronomical Observatory of the University of Tokyo in Azabu (which was thenrelocated to the present location in Mitaka in 1924). Then, in 1988, Tokyo Astronomical Observatory
was combined with the Latitude Observatory and part of the Nagoya University Research Instituteof Atmospherics to establish NAOJ in its modern form. In this way, NAOJ has experienced Japan's
modernization throughout its long heritage, which can be seen if you walk around Mitaka Campus andview the number of beautifully preserved Registered Tangible Cultural Properties.
In 1999, after nine years of construction and more than a century after the dawn of modern Japanese
astronomy, NAOJ completed the Subaru Telescope, an 8.2-m optical-infrared telescope embodying
Japanese technology, near the 4200-m summit of Maunakea in Hawai‘i. Although this year marks
24 years since its first light, the Subaru Telescope is still expected to achieve significant results
throughout the 2020s with its ultra-wide-field-of-view unattainable on other large telescopes.
Following the Subaru Telescope, NAOJ contributed to construction of the Atacama Large Millimeter/
submillimeter Array (ALMA), composed of 66 antenna elements, on a 5000-m plateau in Chilein collaboration with North American, European, and East Asian partners. ALMA started its firstobservations in 2011 and has achieved significant accomplishments. NAOJ is now constructing theThirty Meter Telescope (TMT), an optical-infrared telescope with a 30 meter aperture, on Maunakea incollaboration with the United States, Canada, China, and India.
Besides these, NAOJ is a partner in KAGRA, the Large-scale Cryogenic Gravitational Wave Telescope
led by the University of Tokyo and serves as an international hub for multi-messenger astronomy. In
addition, ATERUI II, the world's fastest supercomputer for astrophysical calculations, is generatingsynergies between observations and theoretical/numerical simulations with its peak performance of
3 Petaflops. Other projects have also achieved glorious results, including not only the Hinode Solar
Observatory, which was developed in collaboration with JAXA, NASA, and other agencies, but also
the lunar orbiter SELENE (Kaguya), the space VLBI satellite HALCA, and two CLASP sounding rocket
experiments. NAOJ will continue our efforts on space missions by leveraging our scientific andtechnological assets.

38

Image from a simulation of dark matter halo structure and evolution.
(Simulation: Tomoaki Ishiyama, Visualization: Hirotaka Nakayama, NAOJ 4D2U Project.)During the development from the Subaru Telescope to ALMA, significant scientific discoveries haveseamlessly continued to be made, such as the discovery of the most distant galaxies in the Universe;
amazing images of protoplanetary disks in which exoplanets are forming; and the world's firstextensive 3D map of dark matter. In the near future we expect that the true nature of dark matter anddark energy will come to light, a detailed model of planet formation will be established, and valuable
insights into exo-planet environments that could harbor life will be obtained. These achievements will
enhance Japan’s international presence, stimulate an interest in science among the Japanese people,
especially the younger generation, and instill pride and confidence in them.
As an open-use institute for universities, NAOJ mediates different opinions within researchcommunities as well as developing large observational facilities that cannot be supported by individual
universities and promotes their open use. Nowadays, astronomy is rapidly becoming interdisciplinary
and its domain is expanding into basic physics, chemistry, and life science, and NAOJ serves as a
hub for such expanding research. Perusing an advanced science like astronomy needs a significant
budget for construction and operation. On the other hand, in view of Japan’s severe financial situation,
we must continuously review the merits of existing research facilities and leverage the technologicalassets of NAOJ to address issues that industry faces and contribute to national endeavors.
In the not-so-distant future, I believe, environments harboring life will be discovered on planets beyond
the Solar System. Then, finding alien civilizations will become the next frontier for astronomy. With
your continued support we can expect the field of astronomy, which has been nurtured for more than
three centuries in Japan, and NAOJ in particular, to be vigorous in the future.

NAOJ Director General

Dr. Saku Tsuneta
39Inter-University Research Institute Corporation
National Institutes of Natural Sciences

National Astronomical
Observatory of Japan
2-21-1 Osawa, Mitaka, Tokyo, 181-8588, Japan
Phone +81-422-34-3600
https://www.nao.ac.jp/en/40