The NASA/ESA Hubble Space Telescope shot this stunning image of a barred spiral galaxy called NGC 4731.
This Hubble image shows NGC 4731, a barred spiral galaxy some 43 million light-years away in the constellation of Virgo. Image credit: NASA / ESA / Hubble / D. Thilker.
NGC 4731 is located approximately 43 million light-years away from Earth in the constellation of Virgo.
Otherwise known as IRAS 12484-0607, LEDA 43507 or UGCA 302, it is classified as a barred spiral galaxy.
“Barred spiral galaxies outnumber both regular spirals and elliptical galaxies put together, numbering around 60% of all galaxies,” the Hubble astronomers said.
“The visible bar structure is a result of orbits of stars and gas in the galaxy lining up, forming a dense region that individual stars move in and out of over time.”
“This is the same process that maintains a galaxy’s spiral arms, but it is somewhat more mysterious for bars: spiral galaxies seem to form bars in their centers as they mature, accounting for the large number of bars we see today, but can also lose them later on as the accumulated mass along the bar grows unstable.”
“The orbital patterns and the gravitational interactions within a galaxy that sustain the bar also transport matter and energy into it, fuelling star formation.”
“Indeed, the observing program studying NGC 4731 seeks to investigate this flow of matter in galaxies,” they added.
First discovered by the German-born British astronomer William Herschel on April 25, 1784, NGC 4731 has a diameter of about 80,000 light-years.
Together with the galaxy LEDA 43526, it forms the interacting pair of galaxies Holm 472.
NGC 4731 is also a member of the NGC 4697 group of galaxies, which is located near the Virgo supercluster.
“Beyond the bar, the spiral arms of NGC 4731 stretch out far past the confines of this close-in Hubble view,” the astronomers said.
“The galaxy’s elongated arms are thought to result from gravitational interactions with other, nearby galaxies in the Virgo cluster.”
The color image of NGC 4731 includes ultraviolet, near-infrared and optical observations from Hubble’s Wide Field Camera 3 (WFC3).
Six filters were used to sample various wavelengths. The color results from assigning different hues to each monochromatic image associated with an individual filter.
“The abundance of color illustrates the galaxy’s billowing clouds of gas, dark dust bands, bright pink star-forming regions and, most obviously, the long, glowing bar with trailing arms,” the researchers said.
Source : Breaking Science News