CASTOR
The Cosmological Advanced Survey Telescope for Optical and uv Research

The Cosmological Advanced Survey Telescope for Optical and uv Researchhttps://www.castormission.org

CASTOR

松田有一、岩田生、早野裕、田中賢幸、小山佑世（国立天文台）

CASTORの概要
The Cosmological Advanced Survey Telescope for Optical and uv Research・2026年打ち上げを目指す口径1m紫外線可視 CASTOR
光広視野宇宙望遠鏡（500億円規模）
・3色同時撮像広視野カメラ（150-550nm、0.25平方度、0.15秒角分解能）はすばるとの親和性が高い
・カナダ（CAS）、アメリカ（JPL）、インド（ISRO）、イギリスによる国際プロジェクトであり、日本から望遠鏡や装置などでも貢献できる可能性もある

CASTOR vs. Hubble: Field of View
The Cosmological Advanced Survey Telescope for Optical and uv ResearchCASTOR (g)CASTOR (u)CASTOR (UV)CASTOR

HST/ACS

The CASTOR Primary Science Survey
The Cosmological Advanced Survey Telescope for Optical and uv Research

CASTORNG THE PRIMARY SURVEY

CASTOR’s Science Goals
The Cosmological Advanced Survey Telescope for Optical and uv Researchs becomea robustSURVEY
science where all predictions from the standard model
PRIMARYe discovery of dark energy at the end of the 1990s was a surprise, but it
暗黒エネルギー
系外惑星the debate on thehe Big Bang.
Nevertheless, this discovery re-activatedtant, Λ. The nature of dark energy is pointing to fundamental questions
ty in quantum physics. The situation with dark matter is similar to dark
has a longer history than dark energy, but its nature also remains
discovery.

••energy budget of the universe is of unknown origin, the Big Bang model
des an amazingly convincing picture of our universe — its past, current
esentPRIMARY
knowledgeSURVEY
can be succinctly summarized as follows (Planckuniverse with nearly zero curvature, which started 13.8 billion years ago
of general relativity. The mass energy density today is ~0.3, where 75%
ure 2-8 for LSST only. This plot is from Mandelbaum et al. (2018).
the remaining ~0.7 of the energy budget.

he stage IV level of precision on dark energy constraints can only be achieved whensing analysis with other probes: the green contours show the supernovae LSST Y10rong Lensing Y10 constraints. The resulting contours combining all LSST probes,), is the small dark ellipse at the center. To these constraints it will be possible tocillation with DESI and the cosmic microwave background constraints with CMB
sson here is the dark energy is best constrained by combining probes.

dark energy that are, at the moment, only theoretical propositions thatf fundamental physics. Dark energy is most commonly parameterized as
p=[w0 + wa (1-a)] ρCASTOR

Mission Design: Telescope and Structure
Telescope:

The Cosmological Advanced Survey Telescope for Optical and uv Research• Three Mirror Anastigmat (lightSystem QE

weighted Zerodur)

CASTOR

Support Structure:
Wavelength (nm)• Baseplate panel• Metering Struts• Top Plate Panel

PrimaryTop Plate Panel

BaffleMetering• M2 Tip/Tilt/Focus MechanismStruts• Baffle System(3 bipods

Secondary Mirror (M2)

Primary Mirror(M1)Baseplate
Tertiary Mirror (M3)
PanelMission Design: Launch and Orbit
The Cosmological Advanced Survey Telescope for Optical and uv Research
Astrosat launch,09/28/2015• Polar Satellite Launch Vehicle (PSLV): a possible ISRO contribution to CASTOR.
• 800 km sun-synchronous low-Earth orbit.
• dawn-dusk polar terminator orbit.

PSLV Accommodation

CASTOR