Celestial hemisphere:  Northern  ·  Constellation: Ursa Major (UMa)  ·  Contains:  NGC 3675  ·  PGC 2225399  ·  PGC 2226754  ·  PGC 2227347  ·  PGC 2229486
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Flocculant spiral NGC 3675, lowenthalm
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Flocculant spiral NGC 3675

Acquisition type: Lucky imaging
Getting plate-solving status, please wait...
Flocculant spiral NGC 3675, lowenthalm
Powered byPixInsight

Flocculant spiral NGC 3675

Acquisition type: Lucky imaging

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Description

Here is a nice little 10th magnitude flocculant spiral galaxy in Ursa Major. You can see numerous pale blue and pale pink star forming regions peeking out from behind the numerous bands of dust. The nucleus looks like its on fire. The galaxy is about 58 million light years away from us and is a member (at the very outer edge!) of a rich cluster of galaxies in Ursa Major that includes M106 as its brightest member and M109 as another famous member. The overall galaxy is about 4 by 7 arc minutes making it similar in size to our own galaxy at about 100,000 light years in diameter.

I notices a couple of blue stars that looked like they might be interest. The pale blue dim "star" at the upper left turns out to be the 19th magnitude quasar SDSS J112550.22+434443.2 with a redshift of z = 0.88364 making it about 7.8 billion light years away.

The other brighter intensely blue star at the very lower right corner of the image is 16th magnitude

2MASS J11262812+4321041. I assumed it must be a nearby white dwarf, but looking carefully at data on this star in SIMBAD I noticed that it ad a parallax of 0.0000204±0.1018 arc seconds. This has a pretty large error, working out to somewhere between 3.26/0.0001222 = ~27,000 light years out to 3.26/0.0000204 = ~160,0000 light years as the median measurement. That puts it well out into the halo of our galaxy, making its bright youthful color odd in that its quite far away from any star forming region where it could have formed recently. A bit of a mystery, with no papers discussing it that I can find. It looks to have a negative color index, making it likely a B star, with a lifetime of no more than 10 million years, which isn't a lot of time to get so far away.

I collected data on several nights with so-so seeing at bin 2 and then got another couple of images at bin 1 on nights when the seeing was better and combined them all for this image at an effective binning of bin 1. Each of the 7 images stacked here were 240 two second exposures live stacked in SharpCap.

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