A gargantuan star, measuring 1,300 times the size of our sun, has been uncovered 12,000 light-years from Earth — it is one of the ten biggest stars known to exist in our galaxy. The yellow hypergiant even dwarfs the famous stellar heavyweight Betelgeuse by 50 percent. While its hulking mass may be impressive, astronomers have also realized that HR 5171 is a double star with a smaller stellar sibling physically touching the surface of the larger star as they orbit one another.
The Sagittarius Window Eclipsing Extrasolar Planet Search, or SWEEPS, was a 2006 astronomical survey project using the Hubble Space Telescope's Advanced Camera for Surveys - Wide Field Channel to monitor 180,000 stars for seven days to detect extrasolar planets via the transit method.
The stars that were monitored in this astronomical survey were all located in the Sagittarius-I Window, a rare transparent view to the Milky Way's central bulge stars in the Sagittarius constellation as our view to most of the galaxy's central stars is blocked by lanes of dust. These stars in the galaxy's central bulge region are approximately 27,000 light years from Earth.
The same phenomenon that causes a bumpy airplane ride, turbulence, may be the solution to a long-standing mystery about stars' birth, or the absence of it, according to a new study using data from NASA's Chandra X-ray Observatory.
Galaxy clusters are the largest objects in the universe, held together by gravity. These behemoths contain hundreds or thousands of individual galaxies that are immersed in gas with temperatures of millions of degrees.
This hot gas, which is the heftiest component of the galaxy clusters aside from unseen dark matter, glows brightly in X-ray light detected by Chandra. Over time, the gas in the centers of these clusters should cool enough that stars form at prodigious rates. However, this is not what astronomers have observed in many galaxy clusters.