It is one of our neighboring galaxies, located three million light-years away from the Milky Way, and in its bowels holds about 25 million stars. It is one of the most distant objects visible to the naked eye of the Earth and now the NASA Hubble Space Telescope has captured the most detailed and captivating image of the Triangular Galaxy so far.
The image of this spiral galaxy, also known as Messier 33 or NGC 598, has 665 million pixels and shows the central region and its inner spiral arms. To unite the pieces of this gigantic mosaic from February 2017 to February 2018, the Hubble Advanced Camera Research Instrument (ACS) needed to create 54 images and then group them together.
It is, therefore, the most comprehensive panoramic survey of what is the third largest galaxy of the Local Group of galaxies. It is also the smallest spiral. It measures only 60,000 light-years in diameter, compared to 200,000 light-years in the Andromeda galaxy or 100,000 light-years in the Milky Way. The distribution of its stars and the fact that, as the Hubble images show, contains a great deal of gas and dust, material from which stars are created suggests that it is a region of rapid formation of these stars.
Hubble takes a giant image of Triangulum Galaxyhttps: //t.co/JLMpvzofrS
Credit: @NASA , @ESA and M. Durbin, J. Dalcanton and B. F. Williams (University of Washington) pic.twitter.com/7nONS0t7JY
– HUBBLE (@ HUBBLE_space) January 7, 2019
Local group of galaxies
The Local Group is a group of more than 50 gravity-bound galaxies. The largest galaxy is Andromeda, followed by the Milky Way and the Triangle. The rest of the members of this group are dwarf galaxies, orbiting around one of the three largest.
"My first impression when looking at the Hubble images is that there is really a lot of star formation," says astronomer Julianne Dalcanton of the University of Washington in Seattle who led the research. "The intensity of the formation rate of stars is 10 times greater than that of the area investigated in the Andromeda galaxy in 2015," he adds.
In fact, the new stars, astronomers have discovered, are formed at an approximate rate of solar mass every two years. And it was the abundance of gas in the Triangle that led scientists to conduct such detailed research.
The Triangle, under conditions of dark sky without light pollution, can be seen with the naked eye, like a weak and nebulous object located in the constellation of the Triangle.
Observations made from the Triangular Galaxy, added to those of the Milky Way and Andromeda, are very valuable because they help astronomers better understand how the process of star formation and evolution is.