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Upgrade plan of the MOA 1.8-m telescope. F. Abe MOA collaboration. 19 Jan. 2009, 13th Microlensing Workshop @ Paris. Discovery of Neptune. In 1846, a mathematician of Observatoire de Paris , Le Verrier predicted a new planet Independent prediction was made by Adams, UK - PowerPoint PPT Presentation
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Upgrade plan of the MOA 1.8-m telescope
F. Abe
MOA collaboration
19 Jan. 2009, 13th Microlensing Workshop @ Paris
Discovery of Neptune
• In 1846, a mathematician of Observatoire de Paris, Le Verrier predicted a new planet
• Independent prediction was made by Adams, UK
• Then, Neptune was discovered by Galle at Berliner Sternwarte as per their predictions
Urbain Jean Joseph Le Verrier
John Couch Adams
Predictions were essential
Discovery of OGLE 2005-BLG-390Lb
Beauliu, et al., 2006
Unpredictable
Discovery of MOA 2007-BLG-192Lb
Bennett, et al., 2007
Single lens light curve
MOA high-cadence observations
OGLE observations
Real time detection of anomalyOGLE 2007-BLG-368/MOA 2007-BLG-308
Sumi, et al., this WS
Short timescale events(MOA 2006-BLG-98)
Kamiya, et al., this WS
tE ~ 1day
Caused by very low-mass star(?):Free-floating planets (?)Brown dwarfs (?)
Current MOA telescope & CCD Camera
• Installed at Mt. John, Observatory, NZ in 2004
• Aperture: 1.8 m• FOV: 2.18
degree^2• Seeing > 1.5”• 1 observation/hour
4 corrector lenses2 degree image circle
Plan of upgrade to get wider FOV
Sako et al., 2008
Optical design (by A. Rakich): Requirements & compromise
• Requirements– FOV: as wide as possible– Primary mirror: use present mirror– No aspheric lens– No special low-dispersion glasses
• Compromise– Replace corrector lenses– Throw out short wavelength (U, B)– Circular effective area
New corrector lenses (4 degree)
By A. Rakich
f/2.964 deg~ 12 deg^2
f/2.912 deg.
BK7BK7 BK7 BK7 BK7
FQ
Vessel Window
3-4 layer coating
All spherical surfaces
Spot diagram (I)
30μm ~ 1.16”
4degreeImage circle~12deg^2
Spot diagram (V)
Target FOV: ~ 10 deg^2
Possible CCD layout
Image circle4 degree in diameter
CCD chip3cm x 6cm0.33°x 0.66°
Total: 52 chips11.3 deg^2
5-6 observations/hourFactor 5 improvement
Honeycomb scan
Honeycomb survey (example)
1 2 3
6 45
7 8 9
Seamless survey can be made without overlap
CCD chips & Electronics
• Current CCDs– E2V CCD4882– 2k X 4k, 3cm x 6cm– Back illuminated– QE: > 90% (500nm), ~30%
(900nm)
• Astronomical Research Camera Gen III
• Hamamatsu CCDs– S10892-01– 2k X 4k, 3cm X 6cm– Back illuminated, full de
pletion (developed by LBNL)
– QE: ~90% (600-850nm) >80% (900
nm)– Factor 2 improvement
• Astronomical Research Camera Gen III
for SUBARU HSC
Time schedule
R&D, cost estimate
Proposal
Lenses
Observations
2009 2010 2011 2012
Oct 30 Apr 1
Camera
Blanks
CCDsetc.
Polishassemble
AssembleTests
Tests Science
InstallationJuly
High quality alert: ~ 2013
Summary• High-cadence observations using wide FOV are
essential in new generation microlensing planet search
• MOA Group is planning to upgrade existing 1.8-m telescope to get ~ 10 deg^2 FOV
• Design of the new optics has been done. • Technical studies of the CCD camera are going t
o start to solve several problems• After several technical studies and cost estimat
e, we will submit the first proposal in this October.
• If it’s approved, observation will be started in the 2012 bulge season
Merci de votre attention