Object of the Week December 7, 2014 - NGC 337 - Cetus

[Paul Alsing]

Object of the Week December 7, 2014 NGC 337 - Cetus
NGC 337 = MCG -1-3-53 = PGC 3572
Intermediate orientation spiral galaxy (SBcd)
R.A.: 00h 59m 50.1s
Dec.: -07°34'41" (2000)
Size: 3.0'x 1.8'
Mag: 11.55 V
Mag: 12.00 B

NGC 337, discovered on Sep. 10, 1785 by William Herschel, is classified as a spiral galaxy... but it looks like a jumbled mess to me! NGC 337 is a starburst galaxy in Cetus.

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Observing this untidy galaxy with my 25" dob, NGC 337 was reasonably bright, not too big, and at first glance it was just another little gray faint fuzzy. However, after peering at this 3:2 elongated fellow for a while, the entire surface became quite blotchy and dappled as the HII areas started to pop in and out. The more I looked the more I saw, with the biggest glowing clump being a curved portion pretty much through the galaxy's center. I tried various eyepieces and powers, and I always seem to prefer the higher powers, perhaps because of the improved contrast they provide.

A primary reason that I chose this object this time around is that NGC 337 has very recently hosted a supernova, Supernova 2014cx, discovered on September 2, 2014 by Koichi Itagaki. This Type II supernova is located 33".7 west and 21".7 north of the center of NGC 337, and was about mag 15.7 at discovery. Within a week it had brightened to mag 14.3, and by November 19th it had dimmed to about mag 15, which is the most recent report that I can find. I suspect it might still be visible now, although I have not had the opportunity... but it is on my list for observing in the next week or 2. I always enjoy observing supernovae because the are transient objects that no one will ever observe again... EVER!

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Less than 1/2 degree almost directly east of NGC 337 is NGC 337A (AKA MCG -1-3-65, PGC 3671), located at R.A.: 01h 01m 33.9s Dec.: -07° 35' 17". This nearly face-on spiral galaxy is twice the diameter of NGC 337, but it has a much lower surface brightness, and I could barely detect it on a good night from the desert east of San Diego, my usual-and-customary observing location. This graphic is from SkyTools, a great program, and the large circle is 30 arc-minutes in diameter...

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So, several target available in this area, so, as usual...

Give it a go and let us know!

[Uwe Glahn]

My notes with 16" from NGC 337:

structured; bright and large appearance; main bar N-S elongated; S end bends toward E with two peaks visible; at N end brighter peak to the W; very faint peak at the S end to the W; another faint peak N of the S bending with dark space between this faint peak and brighter main body

16", 257x, NELM 7m+, Seeing III
http://www.deepsky-visuell.de/Zeichnungen/NGC337.jpg

NGC 337A:

26' E of NGC 337; large but faint glow; concentrated to its middle; directly NW of a 13mag star

[Steve Gottlieb]

Howard Banich and I took a look at this unusual galaxy a year ago (November) in Jimi's scope. But as Uwe's indicates it doesn't take a huge scope to reveal quite a bit of detail. The structure was also quite impressive in my 17.5-inch, back in 2000.

48" (11/1/13): At 488x, NGC 337 appeared bright, fairly large, very irregular with a number of obvious clumps. Although the galaxy is generally elongated 3:2 or 5:3 NW-SE it contains a bright, elongated N-S central region that seems to be a bar. On the south end of the "bar" is a brighter elongated patch extending towards the WSW. Another brighter knot is at the north end of the bar, extending to the east. On the southeast flank of the galaxy is an elongated, fainter patch. The northwest side of the halo extends further out, giving an asymmetric outline, and one or two small knots are involved. A mag 11 star lies 5' E.

17.5" (12/26/00): fairly bright and large, elongated 3:2 NW-SE, ~1.8'x1.2', broad concentration. The appearance is asymmetric -- with a noticeably mottled or irregular surface brightness. Brighter knots within the halo are also clearly visible at moments. The visual impression matches well with the DSS image, which shows a chaotic structure with a number of large HII knots.

The first report of its unusual structure was made through Lord Rosse's 72-inch on 3 Oct 1856. The galaxy was called "pL, not vF. Its brightest part is a line running diagonally, and there is a knot at either end. Perhaps it shaped like an "S".

[Howard B]

Here's my quick sketch from the observation Steve mentions above with Jimi and his 48 inch scope in November 2013:

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My brief notes read: "Asymmetrical and very interesting galaxy with lots of crazy shapes and knots. 7mm (~700x) 21.39 SQM."