00:00The Milky Way has a decidedly fewer number of red giant stars than expected, and for
00:07years it's left astronomers wondering why exactly that is.
00:11But now researchers from the Polish Academy of Sciences believe they may have the answer.
00:15In a paper recently published in the Astrophysical Journal, they have outlined how Sagittarius
00:19A star, or the galactic center of the Milky Way where a supermassive black hole resides,
00:24may be the reason for those missing giant reds.
00:26The scientists outline how Sagittarius A star may have produced an immense stream of gas
00:30that pulled the outer layer from the red giants when it was born.
00:33So how do they know?
00:34Well, the Milky Way has two extremely large bubbles that give off gamma rays both above
00:38and below the galaxy's central plane.
00:40This means that about 4 million years ago when the black hole came to be, something
00:44very large was gobbled up by it.
00:46At that time it would have emitted an energetic stream of gas, powerful enough to superheat
00:50the outer layers of the red giants as they passed through the jet thousands of times
00:54during orbit, turning the cool red giants hot and blue.
