The sky around NGC 7421 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.
NGC 7421 is a spiral galaxy (Sbc) in Grus, 84 million light-years away
NGC 7421 (ESO 346-017, PGC 70083) is a spiral galaxy (Sbc) in the constellation Grus, 84 million light-years away. It shines at magnitude 12.0 and spans 2.4′ × 1.9′ of sky, about 58,600 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.
NGC 7421 is AM 2254-373 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 2254-373 is its position: right ascension 22h 54m and declination -37.3°.
Finding NGC 7421 from Fomalhaut
NGC 7421 lies 7.7° south of Fomalhaut, the magnitude 1.2 star. Three fingers held at arm's length cover about 5°.
NGC 7421 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 53°N, and never sets south of 53°S.
NGC 7421 is 84 million light-years away
The light seen from NGC 7421 tonight left it about 84 million years ago, long before modern humans existed. It ranks 185 of 422 by distance among the galaxies on Go Astronomy. Distance source: Hubble flow, v=1801 km/s, H0=70.
Objects within 6° of NGC 7421
No other Messier, Caldwell or Herschel 400 object lies within 6°.
