Image Credit & Copyright: NASA/ESA Hubble Space Telescope & Luca Limatola.
Dwarf galaxies are hidden gems of the local universe. When I say hidden, in this case I actually mean it as these objects are usually just too dim to observe readily. Except of course, for the Large and Small Magellanic Clouds which if you live in the southern hemisphere you can view any time. The difference is that the LMC & SMC are relatively close while objects like ESO 540-31 here are a whopping 11 million light years distant in the southern constellation Cetus (The Whale).
It’s a tiny member of the Sculptor group of roughly 20 members. This group of galaxies is the closest group to our “Local Group” with its core at a current distance of 12.7 million light years as we see it. Its closest member to the Milky Way is NGC 55 which is only 5 million light years away, just at the border between the two groups. Although the objects in this group are too faint to be viewed with the naked eye, its objects are pretty spectacular.
NAME: ESO 540-31, UGCA 15 and DDO 6.
WHAT S IT?: Dwarf elliptical galaxy.
HOW FAR AWAY IS IT?: 11 million light years.
HOW BIG IS IT?: Roughly 6800 x 3800 light years in diameter and contains a few hundred million stars.
WHERE IS IT? (General): Constellation Cetus (The whale) and a member of the Scuptor Group of galaxies. Also referred to as the Sculptor Filament, NGC 253 Group or the South Galactic Pole Group.
ESA Hubble page for this image: http://www.spacetelescope.org/images/potw1336a/
SIMBAD data for this object: http://simbad.u-strasbg.fr/simbad/sim-id?Ident=ESO+540-31
ESA page for this image: http://www.esa.int/spaceinimages/Images/2013/09/ESO_540-31
ESA Science page for this object: http://www.esa.int/Our_Activities/Space_Science/A_flock_of_stars
ESA Hubble Picture of the Week 2013 (Sept 9): http://www.spacetelescope.org/images/potw/archive/year/2013/
Atlas of the Universe: Sculptor Group: http://www.atlasoftheuniverse.com/galgrps/scl.html
Messier SEDS Sculptor Group: http://messier.seds.org/xtra/ngc/sclgr.html