spacetoday.net: space news from around the webin association with SpaceNews


Middleweight black holes discovered
Posted: Thu, Sep 19, 2002, 10:14 AM ET (1414 GMT)
Astronomers have found evidence for medium-size black holes in the centers of globular clusters. Hubble Space Telescope observations confirmed that a black hole with a mass 4,000 times that of the Sun is in the center of the globular cluster M15, while another 20,000 times as massive as the Sun is in the center of another cluster, G1. Astronomers measured the motions of individual stars and groups of stars around the centers of these clusters to measure the mass of these objects. These black holes are more massive than the stellar-mass black holes left over from supernovae, but much smaller than the supermassive black holes, billions of times as massive as the Sun, found in larger galaxies. Astronomers did note that the ratio of the mass of the black hole to the overall mass of the galaxy is the same for both globular clusters and larger galaxies — 0.5 percent — suggesting that some unknown physical principle may be at work.
<<previous article   next article>>
news in brief
China launches two navigation satellites
Posted: Sun, Jan 14 5:44 PM ET (2244 GMT)

Arianespace plans a record number of launches in 2018
Posted: Sun, Jan 14 5:43 PM ET (2243 GMT)

Orbital ATK wins Galaxy 30 order
Posted: Sun, Jan 14 5:42 PM ET (2242 GMT)

news links
Wednesday, January 17
Here's Why Space Starts At 62 Miles Up
Jalopnik — 6:48 pm ET (2348 GMT)
ASU engineer showcases NASA research for Congress
Arizona State Univ. — 6:47 pm ET (2347 GMT)


about spacetoday.net   ·   info@spacetoday.net   ·   mailing list