Changes

Algol (view source)

Revision as of 17:18, February 11, 2010

1,512 bytes removed , 17:18, February 11, 2010

Line 42: Line 42:

For an [[terrestrial planet|Earth-like]] world to have liquid [[water]] on its surface, it would have to be around 14 AU from the three stars, or the equivalent of an orbit between [[Saturn]] and [[Uranus]]. The hypothetical world would have an orbital period of over 27 years. Because the system itself is very young, it is unlikely such a planet would have time to cool to the point of holding water.

−

~~==Algol Paradox==~~

−

~~===Old Universe View===~~

−

The '''Algol paradox''' came about because according to cosmological theories which suggest the universe is billions of years old, the theory of [[Stellar Evolution|stellar evolution]] predicts stars in a binary star system form at about the same time, and the more massive star will evolve more quickly then the less massive one. The paradox is a result of Algol A being more massive star of the binary pair, yet still a main sequence star, while the less massive Algol B has already reached the subgiant stage in its evolution.

−

Old-universe astronomers believe the paradox is explained though Algol B losing much of its [[mass]]. As Algol B swelled up into the subgiant stage, its companion star, being so close, would produce [[tide|tides]] in Algol B. Matter from Algol B's now swollen outer shell exceeded its '''Roche lobe''' (the volume where the star's gas is gravitationally bound). These outer gases would then be pulled away by the tidal forces into an accretion stream of matter that moves towards Algol A, giving Algol B a teardrop shape pointing towards its companion. As a result Algol B is losing mass at some two hundred millionths of a solar mass a year. Over time, the once massive star been reduced to 79 percent of the Sun's mass.<ref>http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1995BaltA...4...64P</ref>

−

~~===Young Universe View===~~

−

~~For those who reject the notion that the universe is billions of years old, there is no paradox.~~

[[Category:Astronomy]]

JacobB

Automoderated users, edit

3,552

edits