The subject of this Hubble image is LEDA 56779, a spiral galaxy located 300 million light-years away in the constellation of Hercules.
This image from Hubble’s Advanced Camera for Surveys is likely the best of the spiral galaxy LEDA 56779. The brilliant object at right is a star in our Milky Way Galaxy. Image credit: NASA / ESA / Hubble / N. Grogin, STScI.
Also known as MCG+07-33-027 and SDSS J160216.63+425500.9, LEDA 56779 is currently experiencing an extraordinarily high rate of star formation – a starburst.
Normal galaxies produce only about one or two new stars per year, but starburst galaxies can produce a hundred times more than that.
As LEDA 56779 is seen face-on, its spiral arms and the bright star-forming regions within them are clearly visible.
In order to form newborn stars, the parent galaxy has to hold a large reservoir of gas, which is slowly depleted to spawn stars over time.
For galaxies in a state of starburst, this intense period of star formation has to be triggered somehow — often this happens due to a collision with another galaxy.
LEDA 56779, however, is special. While many galaxies are located within a large cluster of galaxies, this galaxy is a field galaxy, which means it is rather isolated.
Thus, the triggering of the starburst was most likely not due to a collision with a neighboring or passing galaxy and astronomers are still speculating about the cause.
In April 2005 a team of astronomers from Arizona State University and Johns Hopkins University discovered a Type Ic supernova – named SN 2005bk – in this galaxy.
This image of LEDA 56779 is a composite of separate exposures acquired by Hubble’s Advanced Camera for Surveys (ACS).
Two filters — a broad V-band (F550M) filter and a near-infrared (F814W) filter — were used to sample various wavelengths.
The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter.
