Author: Akira Kawamura
Translated by Katsuro Nakajima

Cooperated with IYA2009 Japan Committee

CONTENTS
Telescope Assembly … 2Telescope:Basics and Use … 4
Observation of the Moon … 5Moon Map … 6
Observation of Planets … 8
Let’s look at various astronomical objects … 10
What is International Year of Astronomy? … 12

PRECAUTIONS

Warning!
Never direct the telescope at the
Sun ! You will be in danger of
becoming blind. Never try peering
at the Sun through a lens either.

HOSHI no TECHOUSUNTelescope Assembly
Lenses contained in plastic bag●List of componentsⓃObjective lens※Please make sure all listed components are present. Conﬁrm that
there are two identical, ring shaped main-tube holders.
ⒼEye-contact pieceⒸMain-tube holderⒽSight diaphragmⒾO-ring for
objective lens
ⒹNut lockLens-containing bagⒺEye-piece tube-topⓂEye-piece lens-3ⓀEye-piece lens-1ⓁEye-piece lens-2ⒻEye-piece tube-bottom

Tapes & sheetscontained in plastic envelopeⒿNut for tripodⒷMain tube-right half

ⓍSupport paper-boardⓄAdhesive sheet②ⓄAdhesive sheet①ⓅLight-shield tape①ⒶMain tube-left half②③●How to Assemble〜

Assemble step by step following the numbered instructions given below.

ⓀEye-piece lens-1ⓁEye-piece lens-2ⓂEye-piece lens-3ⒽSight diaphragm

Fit Ⓚ:Eye-piece lens-1, Ⓛ:Eye-piece lens-2, Ⓜ:Eye-piece lens-3
and Ⓗ:Sight diaphragm into Ⓕ:Eye-piece tube-bottom. While
doing so, please note the directions concerning Ⓚ:Eye-piecelens-1 and Ⓜ:Eye-piece lens-3, so that they are assembled inaccordance with the magniﬁed drawing shown below.

Magniﬁed Drawing of Eye-piece lenses※Pay attention to direction of lensesⒽSight diaphragmⓁEye-piece lens-2
Groove② Either side may face
Groove①ⒻEye-piece tube-bottomⓀEye-piece lens-1

Face the ﬂat surface
toward the outside andﬁt it into Groove①.

ⓂEye-piece lens-3

Place concave side of this lens against
surface of Ⓛ:Eye-piece lens-2 and ﬁt
them into Groove② together.

ⒺEye-piece tube-topⒼEye-contact piece
Fit Ⓔ:Eye-piece tube-top
with Ⓕ:Eye-piece tubebottom, by jointing protrusions to holes respectively.
Then, ﬁt Ⓖ:Eye-contact
piece secured onto Eye-lens
holder. Now, Eye-piece tube
module has been assembled.

Push Ⓖ: Eye-contact piece sliding
over Eye-piece tube too ﬁt in its full
depth, with grooves aligned withbumps.

ⒻEye-piece tube-bottom
2

Fix Ⓘ:O-ring for objective lens (black rubber ring) around the rim of Ⓝ:
Objective lens. Ⓧ:Support paper-board will help you ﬁx O-ring. Place
Support paper-board on plastic bag, from which Objective lens has beentaken. Holding Objective lens inside the hole in the Support paper-board,
expand O-ring with ﬁngers of both hands (as shown by drawing) and ﬁt it
around rim of Objective lens. After the ring is well ﬁxed, remove Objective
lens from the paper-board being careful to keep the lens surface free ofﬁnger-prints or scratches.
ⒾO-ring for
objective lens※Attention to the direction of lensMagniﬁed drawing
thicker

Eye-pieceⓃObjective lensⒾO-ringⓃObjective lensⓃObjective lenso groovee
Fit intoⓍSupport paper-board

Fit Ⓝ:Objective lens intoⒷ:Main
tube-left half, and then, mountthe previously assembled Eyepiece tube module letting its
screw ﬁt into the casing. Further,place Ⓙ:Nut for tripod underneath the Main tube body.

ⒿNut for tripod

Deposit nut
into the cavity

Unite Ⓐ:Main tube-left half and Ⓑ:Main tube-right half
into one piece, having protrusions ﬁt into hollow holes Eye-piece tube module
respectively. Cover both ends of the Main tube ﬁrmly
with Ⓒ:Main tube holder-1 and 2. Finally, ﬁt Ⓓ:Nut lock
into the groove around Ⓙ: Nut for tripod to complete
the assembly.

ⒸMain-tube holder

Push it ﬁrmly onto the tube.

ⒷMain tube-right half

ⒸMain-tube holder

Ⓙ

d

ipo

r tr

fo
Nut

grooveⒹNut lock

rts
pa
o
tw ce
e ie
th e pite onUnnto
iPush it ﬁrmly
onto the tube

Fit into grooveⒶMain tube-left half

ⒹNut lock※When completed up to this point, please test the telescope s ability to view distantobjects. Adjust eye-piece tube by rotating it, until an inverted image of the object comes
into focus. However, if no image comes into focus, either disposition of eye-piece lenses
or direction of objective lens must be wrong. In this case, we recommend reassembling
the kit from the beginning, carefully consulting the instructions.

Telescope

As a last step, stick Ⓟ:Light-shield tape-① over the joint-seamline at the top and ② and ③ over the joint-seam line at the bottom,
both front and back. Wrap around the main tube with Ⓞ:Adhesive
sheet ①& ②.

Inverted image kept in focusⓅLight-shield tape①ⓄAdhesive sheet ①ⓅLight-shield tape②ⓄAdhesive sheet ②

Assembly completedⓅLight-shield tape③3

TELESCOPE：Basics and Use
The telescope is said to have been invented
about 400 years ago, or in the early 17th Century,in the Netherlands. Being aware of telescopesthat could see distant views at magnification,
Galileo Galilei, an Italian scientist, observed
astronomical objects for the first time in history
in 1609, using a telescope he himself fabricated.
The astronomical telescope you have assembled
here is one designed in accordance with the
Kepler system, of 15 times magnification, amagnification almost equivalent to Galileo’s
but which is now significantly superior in
performance. With this telescope, you will beable to observe astronomical objects in the same
way as Galileo did.
The view you see through the telescope iscalled the image, which appears inverted, upside–
down and left–to–right. While this may seem alittle inconvenient, the universe has neither top
nor bottom and, therefore, the inverted image isquite acceptable as it is for the purpose.

The magnifying power of this astronomical
telescope is 15. This means that you can see
an object across a given distance, as if you
were seeing it from a point as close as 1/15th
the distance. However, 15 times magnification,
also brings with it 15 times as much magnified
blurring or shaking of the image in the scope.
Therefore, when you look at an astronomical
object using hand–held telescope, the object iseasily shaken out of sight and lost from the scope.
Such being the case, it is important that you holdyourself steady by sitting on chair or leaning
on a wall or tree, when you use the telescope.
Otherwise, the most effective method is to set thetelescope on a tripod. The astronomical telescopethat you have assembled now is provided witha screwed nut for a tripod, which is embeddedin the bottom of the main tube. When you set
the telescope onto even a small tripod and lookthrough it without touching it with your hands,
then you can see a very stable image of the object.

7mm

Telescope

Telescope

Erect image(by naked-eye)Inverted image(by astronomical telescope)Out-of-focus image▲ Focusing
Prior to using the telescope for astronomical observation, it should be adjusted to focus
properly. Focus by rotating the eye-piece tube module to adjust. For a person with normal
eye-sight, the astronomical focusing will be best, when the eye-piece tube protrudes fromthe main tube end by approximately 7 millimeters at its shoulder. (See the drawing.) If theeye-piece tube module protrudes further, it will focus on a less distant object.

TargetingdeviceSitting on chairUse, setting ona tripod (for camera)

Holding on the back of chair

Leaning on treeor structure4▲ Sight ing a speci f ic
astronomical object
First, aim at an astronomical
object by naked eye with thetargeting device which sticks
out on top of the main tube as
shown in the drawing. While
holding the telescope steady,slowly shift the observing eye
to the eye-piece tube. Now,
you will see the aimed-for object in sight.

Observation of the Moon

▲When the lunar age
is approx.3, the Moon
appears in the western sky after sunset.

▲When the lunar age
is approx.7, the Moon
appears in the southern sk y after sunset
a n d g o e s d ow n a t
midnight.

waxing moontenof the Moosunlight

crescentmovemshapes seenfrom the Earthn

The most familiar astronomical object to
us will be the Moon, which orbits around theEarth. The Moon's glow is reflected sunlight.
Its brightness is as much as – 13 degrees ofluminance, which is bright enough to reada book by moonlight. The Moon is 3,476
kilometers in diameter or nearly one-quarterthe diameter of the Earth, and its distancefrom the Earth is approximately 380,000
kilometers on average. The figures on the
Moon’s surface is visible even with the naked
eye. The area that appears dark is called
the sea or Lunar mare. But there exists nowater like there does on the Earth. Usingan astronomical telescope, you may look at
various lunar features such as craters, whichlook like holes on the surface, or ranges ofmountains and valleys.
The Moon is an astronomical object thatwaxes and wanes. Along the waning edge isan area that provides a particular advantage
for observation, where the sunlight comesfrom an angle, allowing the uneven lunar
surface to appear clearly in a stereoscopic
image.
The Moon takes about a month to orbit
the Earth. The positional relationship of theMoon–Earth–Sun varies every day. Whenthe Moon comes in the same direction fromthe Earth to the Sun, it is a new moon, thatis, the lunar age being zero. The lunar age
increases by one day, every day. About halfa month following the new moon, it will be afull moon with the lunar age reaching 15.

full moon

the Earth

new moon

the Moonshapes seenfrom the Earthwaning moon

▲ How does the Moon look?
When the Moon comes in the same direction to the Sun from the
Earth, we say it is a “new moon”. At the time of the new moon,
the Earth faces the dark side of the Moon which does not reflect
the sunlight. So, the new moon is invisible. The period from a newmoon to the next new moon is approximately one month. In thecase of the Moon, the cycle of its rotation is equal to cycle ofits revolution going around the Earth. Therefore, we are always
looking at the same side of moon.

▶ Photo of theMoon at the lunar
age 8, taken by
Ku n i h i ko Ka w a moto in Hofu City,
Yamaguchi Pref.
（N i ko n Co o l p i x
775)▲When the lunar age is approx. 15, it is full moon andwill reach the highest pointof the sky at midnight.

5▲ When the l una r ag e
is approx. 21, the Moon
appears at midnight andkeeps rising until it reaches southern sk y aroundthe time of sunrise.

▲ When the lunar
age is approx. 28,
the Moon appears
in the eastern sk y
before sunrise.

Moon Map
Sea・Lake・Baya

H Oceanus Procellarum(Ocean of Storms)
I Mare Nubium(Sea of Clouds)
J Mare Humorum(Sea of Moisture)
K Bay of the center
L Mare Vaporum(Sea of Vapors)
M Sea of Cold
N Sinus Iridum(Bay of Rainbows)
O Seething Bay

A Mare Crisium(Sea of Crises)
B Mare Fecunditatis(Sea of Fecundity)
C Mare Nectaris(Sea of Nectar)
D Mare Tranquillitatis(Sea of Tranquillity)
E Mare Serenitatis(Sea of Serenity)
F Mare Imbrium(Sea of Rains)
G Lake of Dreams

1
4

C

Mountains・Valleys
a
b
c
d
e
f
g

Vallis Rheita
Rupe Altai
Montes Pyrenaeus
Montes Taurus
Rima hyginus
Montes Haemus
Caucasus Mountains

2h Montes Alpsi Montes Apenninus
j Montes Carpathiank Rupes Rectal Montes Riphaeusm Alpine Valley

c

B

East
D

Craters
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19

Petavius
Langrenus
Macrobius
Fracastorius
Catharina
Cyrillus
Theophilus
Posidonius
PliniusManilius
Delambre
Maurolycus
Clavius
Maginus
Tycho
Stofker
Aliacensis
Werner
Walter

20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37

A

Regiomontanus
PurbachDavy
Arzachel
Alphonsus
Ptolemaeus
Herschelarchimedes
Autolycus
Aristillus
Cassini
Plato
Timocharis
Eratosthenês
Copernicus
KeplerAristarchus
Grimaldi

3

d

8

G

6

South
13
14
12

16

15

19
17

b

20

I

21

18

J

k
23

5
6

24

7

22

l

25
26

37

11

West

K

e

9

10

34
O

L

33

i

f

28

8

27
29

G

g

36

F

30

h
M

H

j

32
E

35

m

N
31

North
7

Illustrated by KAGAYA

Observation of Planets
In the starry space, there are other planets likethe Earth which are going around the Sun. These
planets glow reflecting the sunlight. We know ofthe existence of 8 planets of the Sun, consistingof Mercury, Venus, Earth, Mars, Jupiter, Saturn,
Uranus and Neptune, named in the order of theirorbits from the Sun.
Observing such planets every night, you willfind that those planets are rambling across theconstellations. This is because the Earth andother planets are moving along their own orbits

around the Sun, and as a result, their positional
relationships are also varying. Five planets arevisible to the naked eye: Mercury, Venus, Mars,
Jupiter and Saturn. Using the astronomical
telescope that you have assembled, you will
be able to see how Venus waxes or wanes in
its appearance and also to see four satellites
of Jupiter orbiting around it. These satellites
are called Galilean moons because they werediscovered by Galileo. You will also be able to see
the rings of Saturn.

Orbits of the Superior Planets

Orbits of the Inferior Planetsand the access of Mars

2007
2010
Halleyʼs comet

SaturnJupiterthe SunDirection to
the vernal
equinox pointMars

The closest approachto the Earththe Earth

2012

2005

Venus

2020

Mercury
the Sun

UranusDirection to
the vernal
equinox point

2014

Neptune

2018
2016

The closest approachto the Earth＊See orbits of Mars and the Inferior Planets in the next drawing.

▲ Venus
Venus is called the Evening
Star or Morning Star, too. Itbrightly glows in the western
sky after sunset and as wellin the easter n sk y befo resunrise. You can see how it
waxes or wanes, with theastronomical telescope thatyo u h a ve a s se m b l ed. B e
careful not to follow it in the
direction of the sun, since its
direction is near the Sun’s.

▲ MarsMars travels along an orbit immediate outside theEarth’s. Mars glows orange
approaching the Ear th
ever y t wo years and t womonths. With a larger telesco pe, yo u ca n obse r ve
a pattern over its surface.
How it approaches the
Ea r th i s i l l us t rated i n thedrawing, above right.

▲ Satellites of Jupiter
The four satellites of Jupiter,
which are called Galilean
moons, can be viewed by
the telescope you have assembled. Those satellites,from innermost to outermost,are called, Io, Europa, Ganymede and Callisto, and aregoing to change their relative positions as time goeson.

8

▲ Jupiter
Jupiter is the largest planet
within the Solar System andappears to have stripes overits surface. We can see theshape of Jupiter is like a vertically deflated globe. However, the Great Red Spot orsuch details cannot be seen
without a larger telescope.

Mars
Month to approach
the Earth

Jupiter

Constellations

2007 Dec. Gemini2010 Jan. Cancer
2012 Mar. Leo
2014 Apr. Virgo
2016 May Libra
2018 July Capricornus

SaturnConstellations Month in opposition Constellations

Month in opposition

2007 Jun. Ophiuchus
2008 July Sagittarius
2009 Aug. Capricornus
2010 Sep. Pisces2011 Oct. Aries
2012 Dec. Taurus

2007 Feb. Leo
2008 Feb. Leo
2009 Mar. Leo
2010 Mar. Virgo
2011 Apr. Virgo
2012 Apr. Virgo▲ Saturn
Saturn is a beautiful planet
known for its rings. The rings
will be visible even with thetelescope you have assembled, but you will need alarger telescope for observing it in more detail.

▲ The best time to see those planets which travel along orbits outside the Earth’s (superior planets) is when they come in an opposite direction from the Earth to the Sun, that is, in opposite
each other. Mars, going along its own orbit, approaches the Earth every 2 years and 2 months.

Leo2008 7/1
8/1

2009
Virgo

2010

4/1

2/1
2009/1/1
5/1

7/1

2/1 3/1

2011/1/1

12/1

6/1

10/1

9/1

3/1

5/1 6/1
4/1

7/1
11/1
12/1 8/1

2/1
9/1

10/1

6/1
3/1

5/1

4/1

2008/1/1

Moving of Saturn

11/1
8/1
12/1
9/1
10/1
2010/1/1

11/1

Pegasus
9/1

8/1

7/1

6/1
10/1 6/1
11/1
12/1
2011/1/1

2010

AquilaPisces

5/1
4/1

8/1
3/1

Cetus

2/1

7/1

3/1

6/1

9/1
10/1

Moving of Jupiter

2009

5/1

11/1
2010/1/1 12/1

Aquarius

4/1

3/1

7/1 6/1

5/1
4/1
2009/1/1
8/1
12/1 9/1
10/1
11/1
2/1

2008
3/1

Capricornus

Piscis Austrinus
9

2/1
2008/1/1

12/1

Sagittarius

Let’s look at various astronomical objects.
There are numerous, various astronomical objects in thestarry sky. Using a telescope, you will be able to view suchobjects in more details than with the naked eye. Some of theastronomical objects you should see at will be introduced
below.

● The best to look at during April-June★ Let’ s try looking at The Milky Way.
While it looks like a belt of faint, milky light to thenaked eye, you will see through the telescope anaggregation of innumerable stars.

Ursa Major

GeminiCancer★Mizar and Alcor
Mizar and Alcor are a double star, visible
even to the naked eye. One who cannot see well should be able to see themclearly with this telescope.

★Open cluster Plaesepe（M44）this is an open cluster seen in the center of the fourstars composing the back of Cancer’s crab shell.
You will see many stars with this telescope, while
they are barely visible to the naked eye.

● The best to look at during July-September

CygnusLyra
HerculesSagitta★Globular cluster M13
The M13 is in a shape aggregated like aball. This telescope will allow you to view it
as a dimly lit, glowing mass.

★Albireo
AquilaWhile it appears as a single star to thenaked eye, youwill be able to distinguish the two bright yellow andpale blue stars of Albireo through the telescope.

10

Let’s look at various astronomical objects.
● The best to look at during October-December
Cassiopeia

PerseusAndromeda★ Double cluster h-x,
(NGC 869・NGC 884）
This is a double cluster
consisting of twin clusters,
which are somewhat visible to the naked eye. But
it will be clarified throughthis telescope that theya re an agg regation ofnumerous stars.

★ Andromeda nebula（M31 )T he M31 l ook s l i ke the M i l k yWay, where we belong, beinga huge aggregation of morethan 200 billion stars. With thistelescope, you will be able toview the glow shaped like anoval stain.

Triangulum● The best to look at during January-March

Geminis★Great Nebula of Orion（M42）
The M42 is visible as a dimly lit,
glowing mass. Primarily it is anaggregation of hydrogen gas
andnew stars are still being
Monocerosborn within the nebula.

Taurus

Orion★Open clusterPleades M45
The M45 is an open cluster thateven the naked eye will be able
to see as several stars gathered
togethe r. They a re relatively
young stars of 60 to 100 million
years.

11

What is International Year of Astronomy?
The year 2009 is the 400th year since1609 when Galileo Galilei, an Italianscientist, opened a door to the universe
for the first time using an astronomical
telescope. UNESCO, or the United Nations
Educational, Scientific and Cultural
Organization, has designated the year 2009as International Year of Astronomy (IYA in
abbreviation), accordingly.
Across the world, people will look up at thestarry night sky, contemplating the existenceof the Earth and human beings living, in▲ Galileo Galilei（1564 〜 1642）（Illustrated: Tetsuya Takabe） the universe, and discover whatever theycan. That is aim of the International Year of Astronomy.
The Maxim for this year will be “THE UNIVERSE; YOURS TO DISCOVER”
Galileo made many important discoveries in the fields of physics andastronomy. In particular, he performed significant scientific research, directing
his telescope toward the starry sky and observing various astronomical objects.
He built many telescopes of different magnifications. Beginning from1609, he observed the Moon, the Sun, planets of the solar system including
Venus, Jupiter and Saturn, star clusters or nebulae, the Milky Way and otherphenomena, in successfully solving enigmas of the universe, one after another.
Above all, he discovered, through observation of Jupiter and Venus, the proof
for the heliocentric theory that concluded that the Earth like other planets
orbited around the Sun which was positioned at the center of the solar system,
on idea that aroused a tremendous sensation at the time.

▲ Telescope made by Galileo Galilei.
（Illustrated: Tetsuya Takabe）▶ Sketch of asurface of the
Moo n d ra w n
by Galileo.

Warning !
Never look at the Sun
through a telescope,
because you could
critically damage orlose your eyesight !!!
Star-watching guidebook ©HOSHI NO TECHOU/Akira Kawamura, 2008
Supported by Hidehiko Agata, Hiroyuki Takata（NAOJ）
12

SUN