1. The first light of the Corot telescope.
Data obtained by the CNES team
Data processed by L. Jorda, D. Blouin, P. Bernardi

2. Observing conditions. The first images have been obtained
in the vicinity of polaris
trhough a window of the
clean room.
The telescope was not isolated from the ground.
Room vibrations and strong turbulence enlarged the PSF.
The CCD temperature was around 20 C and the sky background was very high.
(~10000 e-)
CorotWeek 8 Toulouse

3. Exposure time
5 sec.
Polaris
mv = 2.02
Tycho
mv = 6.4
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4. CCD E1
Exposure time 8 sec
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5. of the the night, in blue at the end of the night.
Position of the
CCD on the sky
In red at the beginning
of the the night, in blue at the end of the night.
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6. PSF Observed PSF Variability of the PSF on time. Simulated
CorotWeek 8 Toulouse

7. Stars Identification
With a first guess of the line of sight the tycho catalog is projected onto the CCD
with the theoretical distortion model. Couples of catalog and measured stars with the same distance give the identification. After that the line of sight is computed.
CorotWeek 8 Toulouse

8. Test of the distortion model
Estimated Line of sight.
CCD/time
Alpha (deg)
Error alpha (deg)
Delta (deg)
Error delta (deg)
Rol
(deg)
Error rol (deg)
r m s distances
(pixel)
Max
distances (pixel)
A2/01:44:21
87,1251
0,0349
88,9510
0,0006
-67,1982
0,0232
0,6
0,7
A1/01:47:22
87,5936
0,0273
88,9507
-66,9531
0,0120
1.1
E1/00:21:00
66,4108
0,0194
88,9435
0,0004
-67,2207
0,003
0,4
E2/00:24:00
67,2458
0,0450
0,0008
-67,2670
0,0400 1
1.4
Estimated focal length.
Focal length
seismology X (mm)
Seismology Y (mm)
Exoplanet X (mm)
Exoplanet Y (mm)
Measured
1201.1±0.7
1203.6±0.8
± 0.08
± 0.04
Optical model
1201.3
1203.6
1199.3
1203.4
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9. Map of the fitting error on the four CCDs The errors are multiplied
by 70.
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10. The distortion model is OK and will be refined after the launch
Conclusions
The distortion model is OK and will be refined after the launch
The flux measurements indicate an atmospheric
absorption of one magnitude which is a reasonnable value
The focal length is the right one with a precision of
CorotWeek 8 Toulouse