Two Families Of Comets Found Around Nearby Beta Pictoris Star

October 23, 2014

Image Caption: This artists impression shows exocomets orbiting the star Beta Pictoris. Astronomers analyzing observations of nearly 500 individual comets made with the HARPS instrument at ESOs La Silla Observatory have discovered two families of exocomets around this nearby young star. The first consists of old exocomets that have made multiple passages near the star. The second family, shown in this illustration, consists of younger exocomets on the same orbit, which probably came from the recent breakup of one or more larger objects. Credit: ESO/L. Calada

Provided by Richard Hook, ESO

Biggest census ever of exocomets around Beta Pictoris

Beta Pictoris is a young star located about 63 light-years from the Sun. It is only about 20 million years old and is surrounded by a huge disc of material a very active young planetary system where gas and dust are produced by the evaporation of comets and the collisions of asteroids.

Flavien Kiefer (IAP/CNRS/UPMC), lead author of the new study sets the scene: Beta Pictoris is a very exciting target! The detailed observations of its exocomets give us clues to help understand what processes occur in this kind of young planetary system.

For almost 30 years astronomers have seen subtle changes in the light from Beta Pictoris that were thought to be caused by the passage of comets in front of the star itself. Comets are small bodies of a few kilometers in size, but they are rich in ices, which evaporate when they approach their star, producing gigantic tails of gas and dust that can absorb some of the light passing through them. The dim light from the exocomets is swamped by the light of the brilliant star so they cannot be imaged directly from Earth.

To study the Beta Pictoris exocomets, the team analyzed more than 1000 observations obtained between 2003 and 2011 with the HARPS instrument on the ESO 3.6-meter telescope at the La Silla Observatory in Chile.

[ Watch the Video: Artists Impression Of Exocomets Around Beta Pictoris ]

The researchers selected a sample of 493 different exocomets. Some exocomets were observed several times and for a few hours. Careful analysis provided measurements of the speed and the size of the gas clouds. Some of the orbital properties of each of these exocomets, such as the shape and the orientation of the orbit and the distance to the star, could also be deduced.

Continue reading here:

Two Families Of Comets Found Around Nearby Beta Pictoris Star

Related Posts

Comments are closed.