- Beta Pictoris moving group
The Beta Pictoris Moving Group is a young
moving group located relatively nearEarth . A moving group, inastronomy , is a group ofstars that share a common motion through space as well as a common origin.The Beta Pictoris Moving Group is an important object for astronomical study due to its relative proximity to the
Solar System as well as the young age of its component stars in terms of stellar evolution. The starBeta Pictoris is known to have a large disk of gas and dust, possibly aprotoplanetary disk . There is also some evidence of a younggas giant planet around the star. [ [http://www.extrasolar.net/planettour.asp?StarCatId=&PlanetId=58 Extrasolar Visions - beta Pictoris b ] ]The age and distance of the group makes it a prime candidate for the search for
extrasolar planets as well as the study of how stellar systems might form.Constituents
The Beta Pictoris Moving Group consists of 17 stellar systems, comprised of a total of 28 individual component stars, including identified brown dwarves. The core of the group is located some 115
light-year s from Earth, and has an average estimated age of between 10 and 30 million years.The majority of the group is made up of cool, dim K and M class stars. Most are not visible to the naked eye. Beta Pictoris is an important exception, however there are a few other visible components of the group, including :
*
Eta Telescopii
*51 Eridanus
*HD 203
*HD 146624
*HD 165189
*HD 172555 The group covers a region of space largely confined to the
Southern Hemisphere , and lies in the constellations Eridanus, Lepus,Pictor ,Scorpius , andTelescopium .Discovery
An early estimated age for the star Beta Pictoris at about 10 million years proved problematic due to the star's apparent isolation in space. According to current theory regarding
stellar evolution , extremely young stars of this age should be located near other young stars that formed from the same region in space. It is not until significantly later that gravitational interactions with other stars causes stellar 'siblings' to disperse.It was not until 1999 that the situation was resolved by the discovery of a pair of dim
red dwarf stars were discovered to have a similar velocity and age to β Pictoris, lending credence to the estimated age of the star. [cite journal|author = Barrado y Navascués, David; Stauffer, John R.; Song, Inseok; Caillault, J.-P.|title = The Age of beta Pictoris|journal = The Astrophysical Journal|date =August 1 1999 |volume = 520|issue = 2|pages = L123–L126|url = http://adsabs.harvard.edu/abs/1999ApJ...520L.123B|accessdate = 2007-05-14|doi = 10.1086/312162]Further work published in 2001 identified a total of 17
stellar systems with a similar motion and age as the Beta Pictoris moving group, named for the primary member of the association. [http://www.journals.uchicago.edu/doi/full/10.1086/337968]References
Wikimedia Foundation. 2010.