The Sun is moving through Pisces this month, so the constellation's stars are hidden in the Sun's glare. One of those hidden stars is known as BP Piscium, and it's a bit of an oddball. It appears to be an old star that's giving birth to new planets.
The star itself is about twice as massive as the Sun. Its composition and gravity indicate that it's late in life, so it's puffed up like a big balloon.
But a research team led by astronomers at UCLA found that most of the energy that we receive from BP Piscium appears to come from a giant disk of dust that encircles the star. The disk absorbs energy from the star and re-radiates it in the form of heat.
Disks like these are the birthplaces of planets. But planets should form around young stars -- not old, bloated ones like BP Piscium. The planets of our own solar system, for example, formed when the Sun was just an infant.
The astronomers who studied BP Piscium and a similar star suggest that it started life with a small companion star in a close orbit. But as BP Piscium aged, it puffed up and engulfed its smaller sibling. This destroyed the other star, leaving a big cloud of gas and dust. This material has since formed a disk, which is growing thicker.
There's no evidence of planets around BP Piscium, but the disk could be giving birth to some -- a new generation of planets for a geriatric star.
We'll talk about planets in another star system tomorrow.
Script by Damond Benningfield, Copyright 2008
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