NGC2997 is a remarkable object, very faint, very large, very gradually then very suddenly bright middle and 4 arcsec nucleus --
J. L. E. DreyerSurface Brightness: 14.1 mag/arcmin2 after atmospheric extinction
Contrast Index: 0.38
Size: 8'38" x 6'54"
LRGB = 37x120s (per filter) 50% subs at G139 O10 and remaining 50% at G139 O50. This offset of 50 seems to be hard coded in ZWO's ASI Studio, which I was constrained to use to run the cooler after temperature sensor on asi1600 stopped working - the 0C problem. Unfortunately APT, my preferred option, couldn't cope with the failed temperature sensor and kept shutting down the cooler abruptly. Mix of offsets has bloated and saturated brighter stars. Given an option I wouldn't use different offsets (or gains) within the same filter.
HA = 62x120s 50% subs at G139 O10 and remaining 50% at G139 O50
Data collection on 3-Apr-21, 4-Apr-21, 29-May-21, 30-May-21
Weather: April 16C 69% humidity, May 2C 85% humidity (dew heaters on main and guiding scopes)
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