Arp 24 and NGC 3440 (Gary Imm)

Arp 24 and NGC 3440

This image captures 2 objects located in the constellation of Ursa Major at a declination of +57 degrees.

The object at bottom left is Arp 24. The large galaxy in Arp 24 is the magnitude 12.6 galaxy NGC 3445. This galaxy has an apparent diameter of 1.5 arc-minutes and is located 55 million light years away. It is 25,000 light years in diameter.

This is definitely a disturbed galaxy. The core is shifted towards the top. Many blue shades color the disk, which has an odd dark area running below the core. This dark dusty area appears to stretch to the left and connect with the small blue galaxy to the left, which is the magnitude 17 galaxy MCG+10-16-024. This edge-on galaxy appears to have a warped disk. Its distance data indicates it is at the same distance as NGC 3445, so it likely is a true companion. It is a dwarf galaxy, 12,000 light years in diameter.

The tiny yellow galaxy just above and left of NGC 3445is magnitude 15 galaxy 2MASS J10544551+5659589. No distance information is available for this object. Based on its crisp structural shape, it looks like a much more distant galaxy.

Arp 24 was classified by Dr. Arp into the category of Spiral Galaxies – One-Armed. This is surprising to me, since his Companion category would seem more relevant.

The object at top right is NGC 3440. This galaxy is further away at 130 million light years. It is 80,000 light years in diameter. The bright blue star formation regions above left of the core look very odd to me. Some sources say that these bright regions could be a small galaxy companion, although it doesn’t look like that to me.

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Description: Comparison to Original Arp Image

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Status	Advanced success
Started	...
Astrometry.net job	4363509
PixInsight job	L875R5KB6411Q0PSBXF83S9DH73HGQDG
PixInsight queue size	n/a
PixInsight stage	n/a

RA (center)	10h54m14s.119
RA (top/left)	10h55m25s.995
RA (top/right)	10h52m58s.199
RA (bottom/right)	10h53m02s.751
RA (bottom/left)	10h55m29s.552

Dec (center)	+57°03′29″.76
Dec (top/left)	+57°11′24″.27
Dec (top/right)	+57°10′40″.39
Dec (bottom/right)	+56°55′32″.90
Dec (bottom/left)	+56°56′16″.26

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