Star in the constellation Hydra From Wikipedia, the free encyclopedia
HD 86264 is a single[9] star with an exoplanetary companion in the equatorial constellation of Hydra. It is too faint to be readily visible to the naked eye with an apparent visual magnitude of 7.41.[2] The distance to this star, as determined by parallax measurements, is 219 light-years, and it is drifting further away with a radial velocity of +7.4 km/s.[1] A 2015 survey ruled out the existence of any stellar companions at projected distances above 30 astronomical units.[9]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Hydra |
| Right ascension | 09h 56m 57.83878s[1] |
| Declination | −15° 53′ 42.4291″[1] |
| Apparent magnitude (V) | 7.41[2] |
| Characteristics | |
| Spectral type | F7V[3] |
| Apparent magnitude (B) | 7.920[2] |
| Apparent magnitude (J) | 6.505±0.019[2] |
| Apparent magnitude (H) | 6.344±0.038[2] |
| Apparent magnitude (K) | 6.224±0.023[2] |
| B−V color index | 0.510±0.011[2] |
| Astrometry | |
| Radial velocity (Rv) | 7.39±0.13[1] km/s |
| Proper motion (μ) | RA: −14.313±0.024 mas/yr[1] Dec.: −65.057±0.024 mas/yr[1] |
| Parallax (π) | 14.8646 ± 0.0214 mas[1] |
| Distance | 219.4 ± 0.3 ly (67.27 ± 0.10 pc) |
| Absolute magnitude (MV) | 3.23[2] |
| Details | |
| Mass | 1.46±0.01 M☉[4] 1.36+0.04 −0.05 M☉[5] 1.42[6] M☉ |
| Radius | 1.53±0.02 R☉[4] 1.88[6] R☉ |
| Luminosity | 4.02±0.04[4] L☉ |
| Surface gravity (log g) | 4.13±0.04[5] cgs |
| Temperature | 6,616±39[4] K |
| Metallicity [Fe/H] | 0.26±0.03 Dex[7] +0.202[6] dex |
| Rotational velocity (v sin i) | 12.8±0.5[6] km/s |
| Age | 0.8±0.2 Gyr[4] 2.78+0.47 −0.70 Gyr[5] 2.24[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
This is an F-type main-sequence star with a stellar classification of F7V.[3] It is about two billion years old with a modest level of chromospheric activity and is spinning with a projected rotational velocity of 13 km/s.[6] The star is larger and more massive compared to the Sun, and it has a higher metallicity – the abundance of elements with a higher atomic number than helium.[6] It is radiating four times the luminosity of the Sun from its photosphere at an effective temperature of 6,616 K.[4]
In August 2009, it was announced that an exoplanet was found in an eccentric orbit around this host star.[6] The extended habitable zone for this star ranges from 1.50 AU out to 5.06 AU. The planet orbits between 0.86 AU and 4.86 AU, crossing nearly all of the habitable zone.[10] An estimate of the planet's inclination and true mass via astrometry, though with high error, was published in 2022.[11]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥7 ± 1.6 MJ | 2.86 ± 0.07 | 1475 ± 55 | 0.7 ± 0.2 | — | — |
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