Object of the Week, April 30, 2023 - NGC 4666 & Friends - in Virgo
R.A.: 12h45m08.6s
Dec.: -00°27'43"
Size: 4.6'x 1.5'; Magnitude: 10.7
Discovered by William Herschel on February 22, 1784, NGC 4666 (UGC 7926, MCG 0-33-8, PGC 42975) is a type SABc spiral galaxy in Virgo, which indicates a weak bar around the nucleus with moderately wound spiral arms. It has an intermediate inclination of about 50°. NGC 4666 is a bright starburst galaxy with a high level of star formation, and has a large transfer of gas from the bright core into space, hence the “Superwind Galaxy”. It has had (2) supernova within the last decade, in 2014 and in 2019, the latter being determined to be 19 times as massive as our Sun!
As you might suspect, the Hubble picture is quite spectacular…
NGC 4666 Hubble.jpg
In the eyepiece of my f/5 25” Obsession NGC 4666 is big and bright with a bright core and it is quite mottled all over. It is a really nice view.
There are several “friends” in the immediate area, starting with NGC 4668 about 7 arcminutes to the SE, a mag 13 irregular dwarf galaxy (morphology SB(s)d) whose interactions with NGC 4666 sometime in the past is probably the cause of all that starbursting. It is easy enough to observe but offered nothing to me except for a faint somewhat elongated glow. There is a nice wide triple star about 3 arcminutes to the west that spices up the view.
Moving WSW from NGC 4666 about 20 arc minutes we come to NGC 4653, a face-on spiral, very faint and small. I did not detect much in the way of structure; it was just an even and mostly round glow.
NGC4653_-_SDSS_DR14.jpg
Moving another 10 arc minutes WSW we arrive at NGC 4642, another mag 13 edge-on spiral, fairly small and dim but clearly elongated, being about 3 times longer than it is wide.
Lastly, we have NGC 4632, who resides about 45 arc minutes NW of NGC 4666, the outlier of this collection of galaxies. NGC 4232 is the second-brightest of these galaxies at mag 12 or so, and it was elongated about 2:1 and was brighter in the middle, but no structure was noted.
I could only find one picture that showed all of these galaxies at once, and that was from this page but I labeled it here, for clarity...
ngc4653_4666_4632-Labeled.jpg
When we look at the distance to these galaxies, we find that NGC 4632, 4666 and 4668 are all about the same distance, about 55 million light years, whereas the distance to NGC 4653 and 4642 are more than twice that at about 131 million light years. So, it seems like the former 3 are probably an actual
physically associated group, but I have no idea if the other 2 are physically related to each other or not.
SkyTools shows many other galaxies in the general area but they are all up near mag 16-17... so if you are in this area on a perfect night with enough aperture you might give these guys a shot, too!
As always give it a go and let us know!
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