Hubble astronomers provide a beautiful look inside UGC 477, a type of galaxy known as a low surface brightness galaxy.
This Hubble image shows the low surface brightness galaxy UGC 477, which lies in the constellation of Pisces, about 115 million light-years away. Image credit: NASA / ESA / Hubble / Judy Schmidt, www.geckzilla.com.
UGC 477, otherwise known as LEDA 2699 and KPG 15a, is located in the constellation of Pisces, approximately 115 million light-years away.
The existence of low surface brightness galaxies was first proposed in 1976 and confirmed a decade later with the discovery of Malin 1, a giant low surface brightness spiral galaxy roughly 1.19 billion light-years away from us.
Low surface brightness galaxies like UGC 477 are more diffusely distributed than galaxies such as our Milky Way Galaxy and the Andromeda galaxy.
With surface brightness up to 250 times fainter than the night sky, these galaxies can be incredibly difficult to detect.
Most of the matter present in low surface brightness galaxies is in the form of hydrogen gas, rather than stars.
Unlike the bulges of normal spiral galaxies, the centers of these galaxies do not contain large numbers of stars.
Scientists suspect that this is because low surface brightness galaxies are mainly found in regions devoid of other galaxies, and have therefore experienced fewer galactic interactions and mergers capable of triggering high rates of star formation.
Low surface brightness galaxies such as UGC 477 instead appear to be dominated by dark matter.
However, due to an underrepresentation in galactic surveys their importance has only been realized relatively recently.
This image of UGC 477 was taken by Hubble’s Advanced Camera for Surveys (ACS).
It is based on data obtained through two filters: a near-infrared (F775W) filter and a blue (F475W) filter.
