Messier 31
Descubre Foundation, CAHA, DSA, OAUV, Vicent Peris (OAUV), Jack Harvey (SSRO), Gilles Bergond (CAHA)

Telescope

Calar Alto 1.2 meter and 3.5 meterZeiss telescopes.

Camera

LAICA (on the 3.5 meter); 2Kx2K, 24 um pixel SITe (on the 1.23 meter)

Filters

3.5 meter: ALHAMBRA filters centered on 458, 489, 551 and 664 nm. 1.23 meter: Baader RGB.

Exposure Time

3.5 meter: 2 hours. 1.23 meter: 45 minutes (5 min subexposures).

Processing

PixInsight Core 1.7.