| Observation data Epoch J2000.0 Equinox J2000.0 |
|
|---|---|
| Constellation | Crater |
| Right ascension | 11h 22m 05.2898s |
| Declination | -24° 46′ 39.760″ |
| Apparent magnitude (V) | 9.11 |
| Characteristics | |
| Spectral type | K5Ve |
| Variable type | T Tauri |
| Astrometry | |
| Radial velocity (Rv) | 9.25 km/s |
| Proper motion (μ) | RA: -85.45 mas/yr Dec.: -33.37 mas/yr |
| Parallax (π) | 21.43 ± 2.86 mas |
| Distance | ~150 ly (~47 pc) |
| Absolute magnitude (MV) | 10.27 |
| Details | |
| Age | 10 million years |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 98800, also catalogued as TV Crateris (TV Crt), is a quadruple star system approximately 150 light-years away in the constellation of Crater (the Cup). The system is located within the TW Hydrae association. The system consists of "HD 98800 A" and "HD 98800 B" each of which contains two stars.
In 2007, a debris disk was discovered orbiting "HD 98800 B" consisting of two rings which indicates there may be an extrasolar planet orbiting within a distance of 1.5 to 2 astronomical units.
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The system consists of four T Tauri stars that are located within the TW Hydrae association. Within the system, there are two separate systems of binary stars. Each system (separately catalogued as "HD 98800 A" and "HD 98800B") consists of two stars. Although the four stars are gravitationally bound, the distance separating the two binary pairs is about 50 astronomical units (somewhat more than the average distance between the Sun and Pluto). Not much is known about each individual star, except that they are basically Solar twin stars.
Astronomers using the Spitzer Space Telescope's infrared detector discovered a debris disk around the "HD 98800B" binary system. The disk consists of two separate belts. The inner ring extends from a distance of 1.5 to 2 astronomical units from the barycenter of the central binary. The outer ring begins at approximately 5.9 astronomical units from the central binary, and extends out an undetermined distance. The gap between the two rings is ~3 astronomical units. The inner ring is thin, while the inner portion of the outer ring is dense.[1]
Project leader, Dr. Elise Furlan, concludes that the dust generated from the collision of rocky objects in the outer belt should eventually migrate toward the inner disk. But because the system is a double binary system, the dust particles do not evenly fill out the inner disk as expected.
Debris disks are thought to constitute a phase in planetary formation. Because of the gap within the debris disk, the possibility of a planet within the system becomes even more likely. The detected gap could be caused by a unique gravitational relationship between the disk and a possible planet already begun to form, carving out a clear space in the disk. However, the gap could also be gravitational resonance effects of the four stars.
Astronomers believe that planets form like snowballs over millions of years, as small dust grains clump together to form larger bodies. Some of these cosmic rocks then smash together to form Terrestrial planets (such as the Earth), or the cores of Jovian planets (such as Jupiter). Large rocks that don't form planets often become asteroids and comets. As these rocky structures violently collide, bits of dust are released into space.