About a week ago Tracey and I attended the DVAA Members Spring Field Trip at the Big Dipper Lodge (down the road a little bit from the Cherry Springs observing field). Even though the weather forecast wasn't looking good, except for a couple of brief hazy patches, we were treated to decent skies on Thursday night until high clouds started to roll in at around 2:30am (i.e. Friday early AM).
Being "galaxy season", I took advantage of the opportunity for dark skies to image Markarian's Chain that is part of the Virgo Cluster. This cluster is named for Armenian astrophysicist Benjamin Markarian, who discovered that this string of galaxies shares a common motion through space. Its center is about 70 million lightyears from Earth towards the Virgo constellation.
Because I wanted a moderate field of view to capture this area in one shot, I used my Tele Vue TV-85 refractor with a 0.8x reducer/flattener and a camera with an APS-C sized sensor. This combination of equipment yielded a 2.78º x 1.85º field of view which was enough to capture the whole group of galaxies... plus a whole lot more as you will see in the annotated images included as part of this post.
One of the annotated images shows only Messier and NGC-IC galaxies. In that image there are three Messier and 44 NGC-IC objects identified. The other annotated image includes 337 additional PGC galaxies from that catalog. I can't help be amazed by how much is out there and how much can be captured with relatively modest equipment, a relatively short exposure time of slightly over three hours, and from reasonably dark, somewhat hazy skies.
If you zoom in on the annotated image with the PGC galaxies listed you will see that even most of the tiny galaxies in that group are visible in this capture.
Here are the detailed stats about this image:
- Markarian's Chain
- FOV: 2.78º x 1.85º
- April 20-21, 2023 (~22:24 to 02:24 EDT)
- (North is left & East is down)
- 3hr, 10min Exp (38x5m)
- OTA: TeleVue TV-85, w/0.8x FR (480mm FL, 1.6 arcsec/pix)
- Camera: ZWO ASI2600MC-P (-20ºC, G=102), Internal IR Filter
- Mount: ZWO AM5
- Location: Cherry Springs, PA
- ~Bortle 2-3 (SQM ~= 21.65 Measured with SQM-L meter)
- Pre & Post Processing: PixInsight Ver 1.8.9
- Presentation Format: PS CS 5.1
Clear skies,
Gary