A STEP - Observatoire de la Côte d`Azur

A STEP - Observatoire de la Côte d`Azur

A STEP
Antarctica Search for Transiting
Extrasolar Planets
Technical design and
work packages
Telescope choice
IRAIT Telescope
Nasmyth focus adaptation
Excluded because of late
problems of IRAIT
Lots of dedicated systems
for optical photometry would
have been required
Telescope choice
Meade 16 telescope tube
Excluded because of
problems of antarctisation
of that telescope
No real advantage on
Newton telescope
Telescope choice
Minitrust optical design
Optical combination with 3 mirors
for wide field photometry with
active optics – no astigmatism and
achromatic
Excluded because of problems
with focal plane installation,
necessity of redesigning for
Antarctica, size of the central
obstruction and weight (45 cm
nominal design)
Telescope choice
Newton telescope vs Rictchey Chretien
Similar behaviours for fiels around 1 °, but increased
sensibility of RC to telescope tube dilatations
 Important PSF shape changes with differential
dilatations
 RC combination not optimal for slightly defocused
telescopes
Telescope choice
Newton 30 cm or 40 cm
CCD DW 436 (Andor)
Size 2048 x 2048
Pixel size 13.5 mm
1.74 arcsec on sky
According to telescope mount
possible payload
Specific prototype built with
Optique & Vision and ERI
Telescope tube built with an
INVAR structure and carbon fiber
cover
Newton 40 cm nominal
configuration
A STEP Characteristics:
CCD DW 436 (Andor)
Size 2048 x 2048
Pixel size 13.5 mm
1.74 arcsec on sky
Camera use:
Defocused PSF
PSF sampling: FWHM covering ~4 pixel
Time exposure: 10s
Readout time: 10s
Telescope mount:
German Equatorial Astrophysics 1200
With controlled heating
Pointing precision tolerated ~.5”
Data storage: ~500 GB /campaign
Data retrieval at the beginning of
Antarctic Summer for first campaigns
A STEP camera
CoRoT backup available CCDs
 Excluded because of work to
adapt and build CCDs environment
for A STEP
Andor DW436
See Alain presentation
-2048x2048 pixel
-Backwards illuminated CCD
-Limited intra-pixel fluctuations
(Karoff 2001)
-Excellent quantum efficiency in red
-USB2 with antarctisable connection
-Performances guaranted by
constructor
Telescope mount
Astrophysics 1200 or
New Astrophysics prototype if
available on time
See Karim presentation
Newton optical combination
Telescope tube:
INVAR structure
With Carbon fiber cover
4Mpixel DW436
CCD
Wynne
Corrector
Thermal enclosure for
focal instrumentation
Work packages and
early schedule
WP1 - Mechanical design
6 JB Daban
-F Fressin
-F Valbousquet
-K Agabi
-OCA groupe projet
-LUAN groupe projet
Design of telescope tube structure, telescope to mount
fixation
Early discussion on design with groupe projet (Sep ? Oct ?):
Karim, JB, Franck: list of needed specifications – Heike Anders,
Frederic tolerance on changes on PSF shapes for image substraction
Choice of the telescope size to be done according to
telescope mount at the end of October and realisation
Work packages and
early schedule
WP2 - Telescope and Camera software
-A Klotz
-A Blazit
-C Combier
-K Agabi – organizing discussion
-A le Van Suu
-C Carol
Study of telescope guiding and tracking software and
camera reading.
Computer interfaces/redundancy/security
Meeting between LUAN and OHP teams soon (Sep ? Oct ?)
to fix which software can be reused/adapted for A STEP
Work packages and
early schedule
WP-3 Camera thermal enclosure design and tests/
filter and field corrections – > subcategory of WP-1
-A Blazit
-JB Daban
-F Jeanneaux
-Y Fantei
-F Fressin
-K Agabi
 Design of enclosure for camera / wynne corrector /filter or
dichroïc, fixation on telesope tube
Work packages and
early schedule
WP-4 Optical combination – Camera tests
A Blazit V
P Assus
F Fressin
A Erikson + F Pont in reaction mode – F Valbousquet real input
 Zeemax simulations of the field – PSF shapes on every part
of the field.
Work packages and
early schedule
WP-5 - 2007 campaign tests
-D Mekarnia V
-FX Schmider
-E Fossat
-K Agabi + F Valbousquet V + V : optical experiments – small mirrors
including tulip mirror in zerodur September
 Logistic needs for A STEP : to be defined for September 11
Checking the availability of new “optical experiments” site at Dome
C, or preparing A STEP for Concordiastro site
Testing specific treatment on zerodur mirror at different places –
behaviour of frost - optical behaviour of mirrors Foucault test
 What do we send at Dome C in 2 months ?
 Additional tests on Astro 1200 ? Different payloads ?
Work packages and
early schedule
WP-6 Dome C specific problems: open questions
that require study groups
- Karim V
 How to do flat fields at Dome C ? Mandatory for good
photometric precision – frequency needed ?
 Necessity of a protection for bad condition days/summer ?
Availability of “flower domes” ?
 Electrical problems/overcharges – all electronic control
 Duplication ? Of camera ? Encoder (mount) Control
computer
 Who will run A STEP in 2007 ?
Work packages and
early schedule
WP–7 Data pipeline – Light curves extraction and analysis
-H Rauer V
-A Erikson
-F Pont
-T Guillot
-FX Scmider
-F Fressin
 What is reused from BEST data pipeline ? Design of the alarm
mode and photometric control. What has to be fixed before A STEP
departure for Dome C?
Need to drive A STEP on sky in France before computing the real
pipeline – define specific alarm mode too –
 Proposal: input from Heike – development as a team approach –
raise fundings – archiving A STEP data – Proposal fro A STEP/BEST
2 comparisons/summer/winter network - internal DLR funding
application by spring 2007
Work packages and
early schedule
WP-8 Target fields selection – survey strategy
-T Guillot
-FX Schmider
-F Pont
-H Rauer
-C Moutou
-M Deleuil
-S Aigrain
-F Fressin
 Need for preliminary observations – or data base on target fields ?
Specific needs for seismology targets ?
 Target field selection from Holger thesis
Starting discussion with Marseille field selectors for CoRoT
Work packages and
early schedule
WP-9 Data analysis – Follow up of candidates
-T Guillot
-FX Schmider
-F Pont
-H Rauer
-A Erikson
-F Bouchy
-F Fressin
-S Aigrain
-C Moutou
 What is necessary to fix soon ?
Work packages and
early schedule
WP-10 Future prospects – the best design for global transit search
-T Guillot
-H Rauer
-Y Fantei : internet site soon
-A Erikson
-F Pont
-FX Scmider
-F Fressin
 comparative simulations with CoRoTlux – experience from BEST-2 –
A STEP connection and CoRoT preliminary results
Necessity to propose different designs soon for visibility and
outreach ?
Developping webpage / internal and public ? Yan Fantei
Observatoire de la Côte d'Azur (Laboratoires Cassiopée et Gemini):
THE
A STEP
TEAM
Tristan Guillot
(PI)
Scientific preparation, operation supervision, preparation of
modelling tools, analysis of the results and scientific interpretation
Francois Fressin (IS)
Scientific and technical preparation, modelling tools, analysis of
the results and scientific interpretation
Alain Blazit
Responsible of the camera team; Developpement of test and
acquisition tools.
Jean Gay
Follow-up of the telescope conception; Technical preparation,
optical properties modelling
Yves Rabbia
Telescope environment, follow-up of the telescope conception
Jean-Pierre Rivet
Telescope environment, flat fielding system
Dominique Albanese
Camera control softwares & camera testing expertise
Laboratoire Universitaire d'Astrophysique de Nice:
François-Xavier Schmider
Scientific and technical preparation (telescope), Dome C logistics,
analysis of the results and scientific interpretation
Karim Agabi (PM)
Technical preparation, Dome C logistics, telescope design and
telescope control systems
Jean-Batiste Daban
Technical preparation, Dome C logistics, telescope design and
telescope control systems
Dome C logistics, analysis of the results and scientific
Schedule of A STEP