The sky around AM 2309-284 at true scale, north up and east left, with stars to magnitude 8. The circles show the field of a low-power eyepiece and of 10×50 binoculars.
AM 2309-284 is an elliptical galaxy in Sculptor, 80 million light-years away
AM 2309-284 (NGC 7507, PGC 70676, MCG-05-54-022) is an elliptical galaxy in the constellation Sculptor, 80 million light-years away. It shines at magnitude 10.0 and spans 2.8′ of sky, about 65,000 light-years across. It is a telescope object, 6 inches or larger, and it is highest in the evening sky in October.
Galaxy: a system of billions of stars, gas and dust held together by gravity, far outside the Milky Way. Spiral galaxies have a disk with arms; elliptical galaxies are smooth, round or oval swarms of older stars.
AM 2309-284 is AM 2309-284 in the Arp-Madore catalog
Halton Arp and Barry Madore listed it in A Catalogue of Southern Peculiar Galaxies and Associations (1987), from their search of the UK Schmidt southern sky survey plates. The number 2309-284 is its position: right ascension 23h 09m and declination -28.4°.
Finding AM 2309-284 from Fomalhaut
AM 2309-284 lies 3.3° east of Fomalhaut, the magnitude 1.2 star. Three fingers held at arm's length cover about 5°.
AM 2309-284 is highest in the evening in October
The chart gives its height above the horizon at 9 pm through the year, from 60°N to 40°S. It can be seen from the whole southern hemisphere and north to about 61°N, and never sets south of 61°S.
AM 2309-284 is 80 million light-years away
The light seen from AM 2309-284 tonight left it about 80 million years ago, long before modern humans existed. It ranks 182 of 490 by distance among the Arp-Madore galaxies on Go Astronomy with a measured distance. Distance source: Cosmicflows-4 (Tully et al. 2023), SBF.
