NGC 2903

2/27/26 - No clouds, giant moon (82%).  Because of the size and duration of the moon (all night), narrowband imaging is really necessary... but there are limited targets in view.  Noted M97 is at a favorable position. 

Seeing forecast for 02/27-28/2026 from meteoblue showing almost no clouds but large persistent moon.

Seeing forecast from clearoutside for 02/27-28/2026 showing favorable conditions overnight.

Starting around 20:00, launched a polar drift alignment in PHD2 running on the Odroid C4 desktop over RDC.  Started at ~28' and after two adjustments (to the left, pre-meridian flip) brought this down to 0.26'.  Ran an autofocus in the background with the venerable Meade zero-shift autofocus hanging off the Shoestring Astronomy controller. Reached a minimum HFR of 3.76 after six iterations.  Low temperatures were expected near freezing and so set the SVBony Sv405CC chiller at 0C.

After slewing to M97 and starting the focus routine, noted that it's still buried in trees and unlikely to emerge over time.  Switched sadly to NGC 2903.  Started crafting a scheduler with 2x80s UV/IR filter light frames followed by 20x120s dual narrow-band filter light frames... but after seeing an example UV/IR light frame, switched this to just 20x80s UV/IR lights for the duration.

Noted that guide errors from PHD2 were low (~1" RMS).

Ultimately, 145x80s light frames for NGC 2903 were collected through 02:35.  

Ekos Analyze tab for light frame collection with the UV/IR filter for NGC 2903 overnight on 02/27-28/2026 showing reasonable guide errors (~1"RMS) with about an hour break stemming from a failed meridian flip.

Weewx outdoor weather station measurements for temperature, dew point, wind and wind gust for 02/27-28/2026 showing temperatures just above freezing and no wind overnight.


Indi Allsky backyard camera measurements for 02/27-28/2026 showing no clouds and improving skies but significant sky background from the moon.  Pseudo sky quality metric (top) and star count (bottom).

Around 09:00, collected 20x80s dark frames as well as bias frames at 0C, with gain of 285 and offset 24 to match the light frames. Anticipate being able to use flat frames from the calibration collected on 02/14/2026.


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