At around midnight, I switched over from shooting Messier 108 in the northern sky to spiral galaxy M90 (also known as NGC 4569) high in the south. Southern objects can be a problem because
- There are lots of tall trees to my south
- My mount is positioned just north of center of the observatory to shoot objects straight up in that part of the sky (like M108)
- I’m too lazy to move it
Targets that are high in the sky like M90 can pose problems for the top of my dome, especially for my Orion Starshoot guider that sits on top of the telescope. It’s one of the reasons I’m hoping to figure out my new Celestron Off Axis Guider as it will use the same image train as the Celestron SCT. That way, I’ll limit the time I’m actually shooting into the dome rather than the sky.
Photography beside a lake brings additional humidity concerns, and my dew heaters couldn’t keep up for long. By 1 am, the telescope lens had been frosted up enough (it still gets below freezing up here!) and half of my photos turned into a blurry mess. I might have to bring back out the dew sheild for spring targets.
Even with my capture issues aside, I was pleasantly surprised to see what came out of Deep Sky Stacker. Although not as sharp as my M108 capture that evening, the colours popped a lot more than the over exposed messes I’ve taken lately.
About Messier 90
Messier 90‘s two spiral arms are clearly visible and you can see lots of star forming activity towards the core. M90 is passing through the Virgo Cluster towards us, and the gravitational pull of those galaxies (including giant M87) has begun to strip the outer gas layers from Messier 90.
Capture details for Messier 97 (NGC 4569)
Frames: 19×120″ (gain: 300.00)
Integration: 0.6 hours
Avg. Moon age: 22.66 days
Avg. Moon phase: 44.59%
Bortle Dark-Sky Scale: 3.00
Astrometry.net job: 3421154
RA center: 12h 37′ 5″
DEC center: +13° 10′ 48″
Pixel scale: 0.719 arcsec/pixel
Orientation: 127.468 degrees
Field radius: 0.466 degrees