Hubble captures what may be the largest spiral galaxy in our local universe

The Hubble Space Telescope, managed jointly by NASA and the European Space Agency (ESA), has taken a stunning new image of a barred spiral galaxy located some 232 million light-years from Earth, in the northern constellation of Perseus. Dubbed UGC 2885, or LEDA 14030, the spiral galaxy is 8,16,000 light-years wide — roughly 8 times the size of the Milky Way Galaxy. Astronomers also think it contains ten times the number of stars as the Milky Way. UGC 2885 has also acquired the nickname ‘Rubin’s Galaxy’ after astronomer Dr Vera Rubin, by Dr Benne Holwerda from the University of Louisville, who observed the galaxy with the Hubble telescope. [caption id=“attachment_7869951” align=“alignnone” width=“1280”] Galaxy UGC 2885 may be the largest one in the local universe. It is 2.5 times wider than our Milky Way and contains 10 times as many stars. This galaxy is 232 million light-years away, located in the northern constellation of Perseus.[/caption] “Dr Rubin measured the galaxy’s rotation, providing evidence for dark matter that makes up most of the galaxy’s mass,” Dr Holwerda said. His research into the size and features of UGC 2885 has been inspired largely by the work of Vera Rubin in the 1980s. Holwerda and his colleagues from Canada and the United States are studying the galaxy to understand what led to its enormous size. “It’s as big as you can make a disk galaxy without hitting anything else in space,” Holwerda said. “Did the monster galaxy gobble up much smaller satellite galaxies over time? Or did it just slowly accrete gas to make new stars?” Holwerda thinks the galaxy appears to be “puttering along, slowly growing.” UGC 2885 is situated in a fairly isolated locale, without many galaxies in striking distance to crash into and disrupt the shape of its disk. But it is close enough to Earth for Dr Holwerda and his co-authors to make some finer observations. For instance, the number of globular star clusters that appear in UGC 2885’s halo. “It is close enough for Hubble observations to resolve the globular cluster population,” the astronomers said.

Another thing the team hopes to study using UGC 2885 are scaling trends — how important physical properties like mass, size, luminosity and colour of galaxy clusters relate to others in the same galaxy or others. “[Many] scaling relations between the globular cluster population and parent galaxy have been observed, but these differ for disk and spheroidal galaxies [which are more massive],” said Holwerda. “This galaxy is an ideal test case of these scaling relations as it lies between spiral and massive ellipticals.” The team of astronomers are expected to present their findings on 8 January 2020 at the 235th Meeting of the American Astronomical Society in Honolulu, Hawai’i.