Star Dust


BetaPictorisDustThus far, Beta Pictoris is the only star which astronomers have detected a giant planet orbiting in a directly-imaged debris disk. The planet, which was discovered at the European Souther Observatory in 2009, goes around the star once every 18 to 20 years. It is being watch to see how a large planet distorts the massive gas and dust encircling the star. These observations should yield new information about how planets are born around young stars. Beta Pictoris is only about 20 million years old.

The images above were taken with Hubble’s Space Telescope Imaging Spectrograph in its coronagraphic imaging mode.  The coronagraph blocks out the glare of the central star so that the disk can be seen. The visible-light images trace the disk to within about 650 million miles of the star. The giant planet orbits at around 900 million miles.

Comparison of the 1997 and 2012 images shows that the distribution of the dust has not changed much over 15 years despite the fact that the entire structure is moving in orbit the star. This implies that the disk’s structure has been smooth and continuous, at least over the period between the Hubble observations.

One more thing … The Beta Pictoris disk is exceptionally dusty. That may have been caused by recent major collisions among unseen planet and asteroid-sized objects in the disk. One bright glob of dust and gas could be the result of the pulverization of a Mars-sized object in a giant collision. (Marvin was unavailable for comment.)

Image Credit: NASA / ESA