Visual observation of Astra satellites
Equipment & Conditions:
- 1m telescope from C2PU (D=1.0m, F=3.4m, 1.820 arcsec/pixel)
- Exposure time 50ms, 100x acquisitions without NUC or with offset correction
- Messier 11, Messier 15, NGC 7331
Astra group:
- ASTRA 1N 9.9 (magnitude J)
- ASTRA 2A 10.3 (magnitude J)
- ASTRA 2F 10.0 (magnitude J)
Courtesy of Alain Klotz, Michel Boër, Jean-Pierre Rivet and Philippe Bendjoya
Results:
Readout noise (132±6) electron/pixel
Dark current (121,000±1,000) electron/pixel/sec at 15°C
Linearity <0.5%
With a 1m telescope, magnitude J=14.6 can be achieved in 5s (100 x 50ms)
Extrapolations:
With -40°C cooling 1.2 magnitudes would be gained on the detection limit
With a 30cm telescope 1.4 magnitudes would be lost on the detection limit