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,[1] 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 11.3774s[1] |
| Declination | −44° 39′ 40.338″[1] |
| Apparent magnitude (V) | 4.64[2] |
| Characteristics | |
| 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: −168.70[1] mas/yr Dec.: −265.69[1] mas/yr |
| Parallax (π) | 57.09 ± 0.72 mas[1] |
| Distance | 57.1 ± 0.7 ly (17.5 ± 0.2 pc) |
| Absolute magnitude (MV) | 3.57[5] |
| Details[6] | |
| Mass | 1.368±0.026[2] M☉ |
| Radius | 1.26[7] R☉ |
| Luminosity | 3.31 L☉ |
| Surface gravity (log g) | 4.29 cgs |
| Temperature | 6,704±63 K |
| Rotational velocity (v sin i) | 71.6[2] km/s |
| Age | 1.11±1.40 Gyr |
| Other designations | |
| 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,[6] 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[7] 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.[6]
Debris disk
editA 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.[12]
References
edit- ^ a b c d e f van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
- ^ a b c d e f g h i Desidera, S.; et al. (January 2015), "The VLT/NaCo large program to probe the occurrence of exoplanets and brown dwarfs in wide orbits. I. Sample definition and characterization", Astronomy & Astrophysics, 573: 45, arXiv:1405.1559, Bibcode:2015A&A...573A.126D, doi:10.1051/0004-6361/201323168, S2CID 55486025, A126.
- ^ a b Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
- ^ a b Hoffleit, D.; Warren, W. H. Jr., "HR 5825, database entry", The Bright Star Catalogue (5th Revised ed.), retrieved February 4, 2011
- ^ Reiners, Ansgar (January 2006), "Rotation- and temperature-dependence of stellar latitudinal differential rotation", Astronomy and Astrophysics, 446 (1): 267–277, arXiv:astro-ph/0509399, Bibcode:2006A&A...446..267R, doi:10.1051/0004-6361:20053911, S2CID 8642707
- ^ a b c Luck, R. Earle (March 2018), "Abundances in the Local Region. III. Southern F, G, and K Dwarfs", The Astronomical Journal, 155 (3): 31, Bibcode:2018AJ....155..111L, doi:10.3847/1538-3881/aaa9b5, S2CID 125765376, 111.
- ^ a b Rhee, Joseph H.; et al. (May 2007), "Characterization of Dusty Debris Disks: The IRAS and Hipparcos Catalogs", The Astrophysical Journal, 660 (2): 1556–1571, arXiv:astro-ph/0609555, Bibcode:2007ApJ...660.1556R, doi:10.1086/509912, S2CID 11879505.
- ^ a b "g Lup". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-07-01.
- ^ Halbwachs, J. -L; et al. (2018), "Multiplicity among solar-type stars. IV. The CORAVEL radial velocities and the spectroscopic orbits of nearby K dwarfs", Astronomy and Astrophysics, 619: A81, arXiv:1808.04605, Bibcode:2018A&A...619A..81H, doi:10.1051/0004-6361/201833377, S2CID 119437322.
- ^ Lopez-Santiago, J.; et al. (2006), "The Nearest Young Moving Groups", The Astrophysical Journal, 643 (2): 1160–1165, arXiv:astro-ph/0601573, Bibcode:2006ApJ...643.1160L, doi:10.1086/503183, S2CID 119520529.
- ^ Eisenbeiss, T.; et al. (August 2013), "The Hercules-Lyra association revisited. New age estimation and multiplicity study", Astronomy & Astrophysics, 556: 19, arXiv:1312.4045, Bibcode:2013A&A...556A..53E, doi:10.1051/0004-6361/201118362, S2CID 119275785, A53.
- ^ Kalas, Paul; et al. (January 2006), "First Scattered Light Images of Debris Disks around HD 53143 and HD 139664", The Astrophysical Journal, 637 (1): L57–L60, arXiv:astro-ph/0601488, Bibcode:2006ApJ...637L..57K, doi:10.1086/500305, S2CID 18293244.