HD 139664
Star in the constellation Lupus
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HD 139664 is a single[9] star in the southern constellation of Lupus. It has the Bayer designation g Lupi; HD 139664 is the star's identifier from the Henry Draper Catalogue.[8] It has a yellow-white hue and is visible to the naked eye with an apparent visual magnitude of 4.64. The star is located at a distance of 57 light years from the Sun based on parallax, and it is drifting closer with a radial velocity of −7 km/s.[2] It is a member of the Hercules-Lyra association of co-moving stars.[10][2]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Lupus |
| Right ascension | 15h 41m 11.3768s[1] |
| Declination | −44° 39′ 40.342″[1] |
| Apparent magnitude (V) | 4.64[2] |
| Characteristics | |
| Evolutionary stage | main sequence[1] |
| Spectral type | F3/5V[3] |
| U−B color index | −0.03[4] |
| B−V color index | +0.413[2] |
| R−I color index | +0.20[4] |
| Astrometry | |
| Radial velocity (Rv) | −7.08±0.03[2] km/s |
| Proper motion (μ) | RA: −169.106[1] mas/yr Dec.: −266.391[1] mas/yr |
| Parallax (π) | 57.4759±0.1312 mas[1] |
| Distance | 56.7 ± 0.1 ly (17.40 ± 0.04 pc) |
| Absolute magnitude (MV) | 3.57[5] |
| Details | |
| Mass | 1.368±0.026[2] M☉ |
| Radius | 1.26[6] R☉ |
| Luminosity | 3.31[7] L☉ |
| Surface gravity (log g) | 4.29[7] cgs |
| Temperature | 6,704±63[7] K |
| Rotation | 0.719 d |
| Rotational velocity (v sin i) | 71.6[2] km/s |
| Age | 1.11±1.40[7] Gyr |
| Other designations | |
| g Lupi, CD−44°10310, CPD−44°7529, GC 21070, GJ 594, HD 139664, HIP 76829, HR 5825, SAO 226064, PPM 320883, LTT 6256, NLTT 40843[8] | |
| Database references | |
| SIMBAD | data |
This is an F-type main-sequence star with a stellar classification of F3/5V,[3] which indicates it is generating energy through core hydrogen fusion. The estimated age is poorly constrained at around one billion years,[7] but the age of the Hercules-Lyra association to which it belongs is 257±46 million years.[11] It has a moderately high rate of spin, showing a projected rotational velocity of 71.6 km/s.[2] The star has 1.37[2] times the mass of the Sun and 1.26[6] times the Sun's radius. It is radiating 3.31 times the luminosity of the Sun from its photosphere at an effective temperature of 6,704 K.[7]
Debris disk
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A debris disk has been imaged around this star using the coronagraphic mode of the ACS instrument on the Hubble Space Telescope. The disk appears to have a dust maximum at 83 AU from the star and a sharp outer boundary at 109 AU. These features may be caused by gravitational perturbations from planets orbiting the star.[13]