HD 89744
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Stern HD 89744 |
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Observation dates equinox : J2000.0 , epoch : J2000.0 |
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| Constellation | Big Bear | ||||||||||||||||||
| Right ascension | 10 h 22 m 10.56 s | ||||||||||||||||||
| declination | + 41 ° 13 ′ 46.3 ″ | ||||||||||||||||||
| Apparent brightness | 5.73 likes | ||||||||||||||||||
| Typing | |||||||||||||||||||
| B − V color index | +0.54 | ||||||||||||||||||
| U − B color index | +0.08 | ||||||||||||||||||
| Spectral class | F7 V | ||||||||||||||||||
| Astrometry | |||||||||||||||||||
| Radial velocity | (−5.6 ± 0.1) km / s | ||||||||||||||||||
| parallax | (25.36 ± 0.31) mas | ||||||||||||||||||
| distance | (129 ± 2) ly (39.4 ± 0.5) pc |
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| Visual absolute brightness M vis | +2.8 mag | ||||||||||||||||||
| Proper movement | |||||||||||||||||||
| Rec. Share: | (−119.41 ± 0.31) mas / a | ||||||||||||||||||
| Dec. portion: | (−138.31 ± 0.22) mas / a | ||||||||||||||||||
| Physical Properties | |||||||||||||||||||
| Dimensions | 1.4 M ☉ | ||||||||||||||||||
| radius | 1.1 R ☉ | ||||||||||||||||||
| Effective temperature | 6208 K | ||||||||||||||||||
| Metallicity [Fe / H] | +0.18 | ||||||||||||||||||
| Age | 8 billion a | ||||||||||||||||||
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Other names and catalog entries |
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HD 89744 is a main sequence star of the spectral class F7 about 130 light years from Earth. It lies in the constellation of Great Bear and has an apparent magnitude of 5.73 mag. HD 89744 is a member of the AB Doradus Movement Cluster .
The star has two companions. The closer, very likely substellar companion with the designation HD 89744 b could be an exoplanet . The outer companion, labeled HD 168443 B, could be a brown dwarf or a cool star.
Inner companion
HD 89744 b orbits the central star in almost 257 days on a strongly elliptical orbit with an eccentricity of approx. 0.7 and a major semi-axis of approx. 0.9 astronomical units (AU). The minimum mass of the object is about 8 Jupiter's masses, which means it could be an exoplanet or a brown dwarf.
External companion
HD 89744 B ( 2MASS J10221489 + 4114266 ) is either a massive brown dwarf or a low mass red dwarf. The object is at an angular distance of 62 ", 996 ± 0", 035 to the central star, which corresponds to a distance of about 2500 AU.
swell
- Mugrauer et al .: Astrometric confirmation of a wide low-mass companion to the planet host star HD 89744 ; in: Astronomische Nachrichten, Vol. 325, Issue 9, pp. 718ff. (2004), bibcode : 2004AJ .... 128.1733G