A STEPA STEP Antarctica Search for Transiting Antarctica Search for Transiting

Extrasolar PlanetsExtrasolar Planets

Technical design and work packages

Telescope choice

IRAIT Telescope Nasmyth focus adaptation

Excluded because of late problems of IRAITLots of dedicated systems for optical photometry would have been required

Telescope choice

Meade 16 telescope tube

Excluded because of problems of antarctisation of that telescopeNo 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

CCD DW 436 (Andor)Size 2048 x 2048Pixel size 13.5 m1.74 arcsec on sky

Telescope choice

Newton 30 cm or 40 cm

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

CCD DW 436 (Andor)Size 2048 x 2048Pixel size 13.5 m1.74 arcsec on sky

Newton 40 cm nominal configuration

A STEP Characteristics:

Camera use:Defocused PSFPSF sampling: FWHM covering ~4 pixelTime exposure: 10sReadout time: 10s

Telescope mount:German Equatorial Astrophysics 1200With controlled heatingPointing precision tolerated ~.5”

Data storage: ~500 GB /campaignData 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

Telescope tube:INVAR structure With Carbon fiber cover

Thermal enclosure for focal instrumentation

Wynne Corrector

4Mpixel DW436 CCD

Newton optical combination

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 VP AssusF 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):

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 BlazitResponsible of the camera team; Developpement of test and acquisition tools.

Jean GayFollow-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 SchmiderScientific 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 DabanTechnical preparation, Dome C logistics, telescope design and telescope control systems

Eric FossatDome C logistics, analysis of the results and scientific interpretation

Lyu Abe Quality control, tests and installation

Cécile Combier Telescope and camera control softwares

François Jeanneaux Mechanical study of the camera environment

Yan Fantei Temperature regulation system, camera control system

Observatoire Astrophysique de Marseille Provence (LAM & OHP):

Claire MoutouScientific preparation, follow-up of transit candidates, photometric reduction

Magali Deleuil Scientific preparation, follow-up of transit candidates

Marc FerrariConsulting on optical properties of the telescopes, tests and optical simulations

François Bouchy Scientific preparation, follow-up of transit candidates

Antoine Llebaria Image processing, stellar photometry

Michel BoerResponsible for providing a telescope control system based on TAROT, scientific interpretation

Hervé Le Corroler Scientific interpretation

Alain Klotz Telescope and camera control software, scientific interpretation

Auguste Le van Suu Computer interfaces, telescope control system

Jérome Eysseric System engineer

Claudine Carol Computer engineer

Observatoire de Genève:

Frédéric PontScientific preparation, specifications, analysis of the results, follow-up of transit candidates, scientific interpretation

Deutsches zentrum für Luft und Raumfart:

Anders EriksonAdaptation of the data reduction pipeline; Experience with running the transit surveys BEST (OHP) and BEST II (La Silla)

Heike RauerScientific preparation, specifications, analysis of the results, comparison of BEST II / A STEP data

THEA STEP TEAM

Schedule of A STEP