Astronomers find S4716, the quickest star in the entire Universe so far
By: Tina Wu
S4716 orbits around the Sagittarius A black hole, which measures 23.5 million kilometers across. This means that this star has to travel 73,826,400 kilometers around the black hole. With its super speed of nearly 8,000 kilometers per second, it can finish one orbital period in four years.
How was S4716 found?
This star was found by astronomers working at the University of Cologne and Masaryk University. They used five different telescopes to observe the star, including the NIR2, the OSIRIS, both in Hawaii, and the SINFONI, NACO, and GRAVITY, from the European Southern Observatory. Four of the five telescopes had to be joined together to get a better look at the star. They propped the instrument up in Chile, and spotted the unusually fast star, which was 215 million light-years away from Earth. Surprisingly, this was the closest to Earth it has ever been spotted.
What have Astronomers discovered about this nimble star?
They have examined this star for around 20 years, and discovered that the S4716 is almost 100 astronomical units (AU) away from Sagittarius A. By astronomical standards, one AU (149,597,870 kilometers) is actually pretty small.
The lead author of the study, Dr. Florian Peissker, says that “For a star to be in a stable orbit so close and fast in the vicinity of a supermassive black hole was completely unexpected and marks the limit that can be observed with traditional telescopes.”
Astronomers also discover that the S4716 is in a star cluster named Sagittarius A*. A star cluster contains a bunch of tightly-crammed stars. The cluster S4716 is comprised of 100 more speedy stars just like it.