The NASA/ESA Hubble Space Telescope has produced a spectacularly detailed image of an isolated dwarf irregular galaxy called NGC 1156.
This Hubble image shows NGC 1156, a dwarf irregular galaxy located 25 million light-years away in the constellation of Aries. The color image was made from separate exposures taken in the ultraviolet, visible and near-infrared regions of the spectrum with Hubble’s Wide Field Planetary Camera 2 (WFPC2) and Advanced Camera for Surveys (ACS). It is based on data obtained through five filters. The color results from assigning different hues to each monochromatic image associated with an individual filter. Image credit: NASA / ESA / Hubble / R.B. Tully / R. Jansen / R. Windhorst.
NGC 1156 is a Magellanic-type dwarf irregular galaxy some 25 million light-years away in the constellation of Aries.
Otherwise known as IRAS 02567+2502, LEDA 11329 and UGC 2455, it has a diameter of 13,000 light-years.
It was discovered on November 13, 1786 by the German-born British astronomer William Herschel.
NGC 1156 has a boxy shape, a larger than average core, and bright blue patches, implying an active star-formation stage.
It is one of the highly isolated and less-disturbed galaxies. Its nearest neighbors are UGC 2684 and UGC 2716, located more than 10 degrees away from NGC 1156.
“NGC 1156 has a variety of different features that are of interest to us,” Hubble astronomers said.
“A dwarf irregular galaxy, it’s also classified as isolated, meaning no other galaxies are nearby enough to influence its odd shape and continuing star formation.”
“The extreme energy of freshly formed young stars gives color to the galaxy, against the red glow of ionized hydrogen gas, while its center is densely-packed with older generations of stars.”
The new image of NGC 1156 features data from a galactic gap-filling program titled ‘Every Known Nearby Galaxy.’
The astronomers noticed that only three quarters of the galaxies within just over 30 million light-years of Earth had been observed by Hubble in sufficient detail to study the makeup of the stars within them.
They proposed that in between larger projects, Hubble could take snapshots of the remaining quarter.
“Gap-filling programs like this one ensure that the best use is made of Hubble’s valuable observing time,” they said.
source: sci.news
