Celestial hemisphere:  Southern  ·  Constellation: Eridanus (Eri)  ·  Contains:  NGC 1241  ·  NGC 1242  ·  NGC 1243
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Arp 304, Gary Imm
Arp 304, Gary Imm

Arp 304

Getting plate-solving status, please wait...
Arp 304, Gary Imm
Arp 304, Gary Imm

Arp 304

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Description

This Astrobin Debut Object is a pair of spiral galaxies located in the constellation of Eridanus at a declination of -9 degrees. This object was classified by Dr. Arp into the category of Double Galaxies.

NGC 1241 is the larger magnitude 12 galaxy, 200 million light years away. This galaxy spans 2.2 arc-minutes in our apparent view, which corresponds to a Milky Way-sized diameter of 130,000 light years. NGC 1242 is the small magnitude 14.6 galaxy, 210 million light years away. It spans 0.8 arc-minutes and has a diameter of 50,000 light years.

Both galaxies look disturbed so they are likely interacting to some degree, even though the distance calculation shows them to be too far apart. These galaxies may be closer together than the above distances show - the redshift calculation may be affected by their rotation around each other.

The smaller galaxy is an unusual 3-armed galaxy, although it was too small to make Arp's Three-Armed galaxy category.

The larger galaxy is a bit of a mess. It looks like it started out as a grand design spiral galaxy with 2 strong arms and an outer ring, but now another star stream “arm” has formed. This arm extends upward towards NGC 1242.

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