BD+20 2457
 Artistic rendering of star BD+20° 2457, how it appears at ≈4 Astronomical Units. | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Leo |
| Right ascension | 10h 16m 44.8635s |
| Declination | +19° 53′ 28.974″ |
| Apparent magnitude (V) | 9.75 |
| Characteristics | |
| Spectral type | K2II |
| B−V color index | 1.18 |
| Variable type | none |
| Astrometry | |
| Proper motion (μ) | RA: –35.20 mas/yr Dec.: –31.70 mas/yr |
| Parallax (π) | 5.00 ± 3.33 mas |
| Distance | 650 ± 330 ly (200 ± 100 pc) |
| Details | |
| Mass | 2.8 ± 1.5[1] M☉ |
| Radius | 49[1] R☉ |
| Luminosity | 624 L☉ |
| Surface gravity (log g) | 2.5 cgs |
| Temperature | 4127 ± 17[1] K |
| Metallicity | –1.00 ± 0.07 |
| Other designations | |
PPM 127264 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
BD+20°2457 is a 10th magnitude K-type bright giant star located between 320 to 980 light years away in the constellation of Leo. This star is very metal-poor, containing only 10% as enriched with elements heavier than hydrogen and helium as our sun, almost classifying this as a population II star. On June 10, 2009, two substellar objects BD+20°2457 b and c were discovered orbiting the star.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥21.42 MJ | 1.45 | 379.63 ± 2.01 | 0.15 ± 0.03 | — | — |
| c | ≥12.47 MJ | 2.01 | 621.99 ± 10.20 | 0.18 ± 0.06 | — | — |
See also
References
- ^ a b c d Niedzielski, A.; et al. (2009). "Substellar-mass Companions to the K-dwarf BD+14 4559 and the K-giants HD 240210 and BD+20 2457". The Astrophysical Journal. 707 (1): 768–777. arXiv:0906.1804. Bibcode:2009ApJ...707..768N. doi:10.1088/0004-637X/707/1/768.
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