The 15 Best Visual Arp Objects

See Arp galaxies for yourself! Here are 15 Arp objects that you can easily see with a 10 inch (and in many cases smaller) telescope. These also reveal a peculiar feature. There are some brighter Arps that do not show their peculiarity and most are too faint for a 10 inch to show themselves at all. All 15 of these are listed in Burnham's Celestial Handbook and many are featured galaxies. Most are identified in the Bright Star Atlas and other magnitude 6 starcharts. Get out there with your telescope, observe, and draw them!

Messier 77, NGC 1068, Arp 37

Eastern Cetus, RA 02h 43m, Dec 00deg 1min

A definite Seyfert-type galaxy. The irregular shape can be seen even in a 4 inch at low to medium powers. M 77 is very close to the bright star delta in Cetus.

NGC 1097/1097A, Arp 77

Center of Fornax, RA 02h 46m, Dec -30deg 16min

An easy object even for a 4 inch but you will need a 10 inch to see 1097a. 1097 is elongated SE-NW with 1097A just 3.5' north of the NW end. This Arp requires medium to high power to see both.

Image courtesy of Al Kelly.

Messier 82, NGC 3034, Arp 337

Northern Ursa major, RA 09h 56m, Dec 69deg 41min

Easily visible with M 81, this galaxy has a very unusual shape and is a star party favorite. Arp 337 is very long and slim.

Image courtesy of Al Kelly.

NGC 3395 and NGC 3396, Arp 270

Eastern Leo Minor, RA 10h 50m, Dec 32deg 59min

This pair of galaxies appear to form an upside down V with the point facing north. 3396 which is the eastern galaxy has a bright nucleus while 3395 has a more even brightness and no distinct nucleus.

Messier 65, NGC 3623 and NGC 3628, Arp 317

Eastern Leo, RA 11h 19m, Dec 13deg 05min

This object is two of three galaxies in the same low power view. M 66 is also in the view. M 65 and NGC 3628 are long rectangular galaxies. 3628 goes E-W and 65 goes N-S.

NGC 3994/3995, Arp 313

Southeastern Ursa Major, RA 11h 57m, Dec 32deg 16min

3995 is the biggest galaxy in the field and 3994 is oval, much smaller and west of 3995. Another galaxy, 3991 is northwest of 3995 and is a smaller elongated galaxy parallel to 3995.

NGC 4038 and NGC 4039, Arp 244

Western Corvus, 12 01.88 -18 51.9

Known as the "Ringtail", this object requires a 10 inch to see the cashew nut shape of the two galaxies together. The north lobe is much brighter than the south lobe. The faint tails which give it its name are invisible visually. A 5.3 magnitude star is 2 degrees SSE of this pair just west of the Corvus trapezoid.

Image courtesy of Al Kelly.

NGC 4435 and NGC 4438, Arp 120

Northern Virgo, RA 12h 28m, Dec 13deg 0min

4435 is the smaller object NW of the center of the larger 4438. However the light is 4438 is concentrated in the center.

NGC 4485 and NGC 4490, Arp 269

Western Canes Venatici, RA 12h 31m, Dec 41deg 38min

4490 is the large elongated galaxy with 4485 NNW and appearing circular. Some can see the dark band just north of the nucleus of 4490 and along the major axis.

Image courtesy Al Kelly.

NGC 4631 and NGC 4627, Arp 281

Southern Canes Venatici, RA 12h 42m, Dec 32deg 32min

The 4631 is shaped like a bar similar to M 82. 4627 is barely visible in a 10 inch 2.7' NW of the brightest part of 4631.

Image courtesy of Al Kelly.

Messier 60, NGC 4649 and companion NGC 4647, Arp 116

Northern Virgo, RA 12h 43m, Dec 11deg 33min

These two galaxies look like two centers in the same galaxy if you use over 100X to view it in a 10 inch f/5 telescope.

NGC 5128, Arp 153

Center of Centaurus, RA 13h 25m, Dec -43deg 01min

One of the brightest galaxies in the sky. Centaurus A has a dark band running through it at 120 degrees that is visible even in a 6 inch telescope. It is easy to view due to its size of 18.2' X 14.5'.

Messier 51, NGC 5194 and companion NGC 5195, Arp 85

Northeast Canes Venatici, RA 13h 30m, Dec 47deg 12min

The Whirlpool Galaxy, two of the brightest apparently interacting galaxies. Dust lanes and the bridge that appears to connect the two is easily visible in an 8 inch or larger scope.

Image courtesy of Chuck Shaw.

NGC 5426 and NGC 5427, Arp 271

Southeastern Virgo, RA 14h 03m, Dec -06deg 04min

Both objects are visible in medium to high power with small and bright centers. They both have a granular appearance with 5427 on top of 5426 and appearing interconnected.

NGC 5560 and NGC 5566 and NGC 5569, Arp 286

Eastern Virgo, RA 14h 20m, Dec 03deg 56min

This object requires a 10 inch to see two of the galaxies. 5566 is the largest and brightest elongated galaxy. 5560 is NW of 5566 and is concentrated while 5566 has 3 or 4 bright knots for the nucleus. 5569 is .2' NE of 5566 and requires a larger scope to see.

This list was compiled by the hard-working observers of the Fort Bend Astronomical Society, under the skillful direction of Mike Brown. This page was developed by Dennis J. Webb, Updated August 10, 1997.

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