Team of Indian astronomers discovers gigantic hydrogen ring around a galaxy far far away

“The optical image of the galaxy AGC 203001 showed no signs of any stars, which is astounding. One of the reasons could be that hydrogen gas is very low in density and its vast expanse could make it unconducive for star formation,” said Yogesh Wadadekar, senior scientist and co-author of the research published on Thursday in the Monthly Notices of the Royal Astronomical Society.


Star-less and off-center hydrogen ring around a galaxy.


A team of astronomers from the TIFR-National Centre for Radio Astrophysics (NCRA) has discovered a rare ring of hydrogen gas surrounding a lenticular galaxy, that is located about 260 million light-years away from Earth. Interestingly, radio emissions from AGC 203001 galaxy originate from a time when dinosaurs thrived on Earth and were observed in December 2017, thanks to the advanced telescopes now available for sky-gazing.

This discovery made use of the Pune-based Giant Metrewave Radio Telescope (GMRT) and Canada-France-Hawaii-Telescope (CHFT) in Mauna Kea, Hawaiian Islands.

Astronomers highlight that the detection of such a galaxy with a hydrogen ring is rare, more so because there were no stars within it. Generally, condensed hydrogen gas acts as a primary source for star formation in any galaxy.

“The optical image of the galaxy AGC 203001 showed no signs of any stars, which is astounding. One of the reasons could be that hydrogen gas is very low in density and its vast expanse could make it unconducive for star formation,” said Yogesh Wadadekar, senior scientist and co-author of the research published on Thursday in the Monthly Notices of the Royal Astronomical Society.


The newly-discovered ring is only the second of its kind ever detected and has a diameter of about four times that of the Milky Way.

Besides stumbling upon such a galaxy with gaseous hydrogen mass settled outside the disc, lead author of the study, Omkar Bait, added that the size of AGC 203001 was as big as the Milky Way.