Supermassive black holes Reference Libraries

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Supermassive Black Hole
2004-10-19 04:45:42

Supermassive Black Hole -- A Supermassive black hole is a black hole with a mass in the range of millions or billions solar masses. A supermassive black hole has some interesting properties differing from his low-mass cousins: -- The average density of a supermassive black hole can be very low, and actually can be lower than water's density. This happens because the black hole...

Seyfert Galaxy
2004-10-19 04:45:42

Seyfert Galaxy -- Seyfert galaxies are spiral or irregular galaxies containing an extremely bright nucleus, most likely caused by a supermassive black hole, that can sometimes outshine the surrounding galaxy. The light from the central nucleus varies in less than a year, which implies that the emitting region must be less than one light year across. They are named for the astronomer Carl...

2004-10-19 04:45:42

Quasar -- A quasar (from quasi-stellar radio source) is an astronomical object that looks like a star in optical telescopes (i.e. it is a point source), but has a very high redshift. The general consensus is that this high redshift is cosmological, the result of Hubble's law and that their redshift indicates that they are typically very distant from Earth; we observe them as they were...

Word of the Day
  • A transitional zone between two communities containing the characteristic species of each.
The word 'ecotone' comes 'eco-' plus a Greek root meaning 'tension'.