Astronomy:TW Hydrae association
The TW Hydrae association is a group of very young low-mass stars and substellar objects located approximately 25–75 parsecs (80–240 light years) from Earth. They share a common motion and appear to all be roughly the same age, 10±3 million years old. It is the youngest such association within 100 pc from Earth.[1] As of 2017, 42 objects (in 23 systems[2]) are assigned to the association confidently, and several dozens — uncertainly. Masses of its known members vary from 5 Jupiter masses to 2 solar masses, and their spectral types vary from A0 to L7.[1]
Some of the best studied members of this stellar association are TW Hydrae (nearest known accreting T Tauri star to the Earth), HR 4796 (an A-type star with resolved dusty debris disk; the most massive known group member), HD 98800 (a quadruple star system with debris disk), and 2M1207 (accreting brown dwarf with remarkable planetary-mass companion 2M1207b).
Included in the association is WISEA 1147, which is a brown dwarf.[3][4][5]
See also
- List of nearby stellar associations and moving groups
- β Pictoris moving group
- AB Doradus moving group
- Scorpius–Centaurus association
References
- ↑ 1.0 1.1 "BANYAN. IX. The Initial Mass Function and Planetary-mass Object Space Density of the TW HYA Association". The Astrophysical Journal Supplement Series 228 (2): 1–62 (look p. 26, 35). 2017. doi:10.3847/1538-4365/228/2/18. Bibcode: 2017ApJS..228...18G.
- ↑ Singular objects are also regarded as "systems" here.
- ↑ Newcomb, Alyssa (20 April 2016). "Lonely Planet Unattached to a Star Found in Deep Space". ABC News. https://abcnews.go.com/Technology/lonely-planet-unattached-star-found-deep-space/story?id=38542912. Retrieved 21 April 2016.
- ↑ "Lone Planetary-Mass Object Found in Family of Stars". NASA. 19 April 2016. http://www.nasa.gov/feature/jpl/lone-planetary-mass-object-found-in-family-of-stars. Retrieved 21 April 2016.
- ↑ Kennell, Joanne. "Astronomers Spot a Lonely Planet-Like Object Floating Freely in Space". The Science Explorer. http://thescienceexplorer.com/universe/astronomers-spot-lonely-planet-object-floating-freely-space. Retrieved 21 April 2016.
 |  |
