Stars and gas swirl around the supermassive black hole at the center of the Milky Way galaxy in this image, which combines views in several wavelengths. Red and green show radio waves from gas in giant clouds around the black hole, while blue, from the infrared Spitzer Space Telescope, shows stars. The black hole, which is about 4 million times as massive as the Sun, is too small to see with even the most powerful telescopes. The entire complex is about 27,000 light-years away, above the "teapot" of the constellation Sagittarius. [NRAO/AUI] We have a full feature on the Milky Way's black hole and the environment around it in the September/October 2011 issue of StarDate magazine.
Milky Way’s Heart II
MORRIS: For every star that we can see in our nighttime sky from Earth, if you were to be at the galactic center, on an equivalent Earth, every star we see would be replaced by a million stars there. So the 6,000 stars visible to the naked eye from a good desert site here on planet Earth would be replaced by 6 billion stars.
Mark Morris is an astronomer at UCLA who’s been studying the center of the Milky Way galaxy since the 1970s.
MORRIS: Some of those stars would be much closer, in all probability, than the stars we see in our nighttime sky, and therefore extremely bright. You might see stars approaching the brightness of the Moon. And the speeds that things move in the galactic center are quite high, so you would see these stars move. Not from night to night, or maybe not even from year to year, but during a human lifetime the sky would change dramatically.
The heart of the Milky Way is the most crowded region in the galaxy, with billions of tightly packed stars. Most of the stars are old, but some of them are quite young. They’re born in giant clusters that are far bigger than those out in our region of the galaxy. And at the very center of it all is a black hole that’s four million times as massive as the Sun; more about that tomorrow.
The black hole and the young stars around it put out tremendous amounts of energy, especially ultraviolet and X-rays. So a night under the stars on a planet at the galactic center would be spectacular — but deadly.
Script by Damond Benningfield, Copyright 2011
For more skywatching tips, astronomy news, and much more, read StarDate magazine.