Image 1: NGC3184, the “Little Pinwheel” Galaxy
On the evening of May 6/7 the intention was to image galaxy clusters or fields of many small galaxies. One option that came up was this galaxy which I’d never seen before. The galaxy field was disappointing (or non-existent) but the little pinwheel is of interest. The equipment wasn’t good for such a small galaxy so I’ll try later when I have the proper setup. The image I did get seems okay.
The Little Pinwheel Galaxy appears in the constellation Ursa Major, the Great Bear or big Dipper. It is called the Little Pinwheel because it resembles M101, known as the “Pinwheel” galaxy. It is around 40 million light-years away from us, well outside the Milky Way galaxy. The galaxy appears white here, but it is actually slightly blue from all the very bright and hot stars in it. Bright blue stars have very short lives before they explode, so we see a lot of recent star formation in this galaxy.
I don’t have any information on how big this galaxy is in terms of solar masses, but given it’s apparent size (7.4 by 7 arcmin) and distance I’d guess that it is half the size of our Milky Way galaxy or smaller.
NGC3184 The Little Pinwheel Galaxy, Lac Teeples, 2024-05-07. 64 minutes of data in 64 second subframes. Celestron RASA-8, ASI6200MC. No filter.
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