Astronomy:HD 168009
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Lyra[1] |
| Right ascension | 18h 15m 32.463s[2] |
| Declination | +45° 12′ 33.54″[2] |
| Apparent magnitude (V) | 6.307[3] |
| Characteristics | |
| Spectral type | G1 V[4] |
| U−B color index | 0.115[3] |
| B−V color index | 0.635[3] |
| Astrometry | |
| Radial velocity (Rv) | −64.9±0.1[5] km/s |
| Proper motion (μ) | RA: −77.290±0.018[2] mas/yr Dec.: −114.748±0.019[2] mas/yr |
| Parallax (π) | 42.9348 ± 0.0158[2] mas |
| Distance | 75.97 ± 0.03 ly (23.291 ± 0.009 pc) |
| Absolute magnitude (MV) | 4.52[3][6] |
| Absolute bolometric magnitude (Mbol) | 4.39±0.06[7] |
| Details[5] | |
| Mass | 0.99 M☉ |
| Radius | 1.14±0.04[7] R☉ |
| Luminosity | 1.43[8] L☉ |
| Surface gravity (log g) | 4.31 cgs |
| Temperature | 5,792±80 K |
| Metallicity [Fe/H] | −0.02 dex |
| Rotation | 5.985±0.019 d[9] |
| Rotational velocity (v sin i) | 3[6] km/s |
| Age | 8.1 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 168009 is a star in the northern constellation of Lyra. It has an apparent visual magnitude of 6.3,[3] placing it just above to below the normal limit of stars visible to the naked eye under good viewing conditions of 6-6.5. An annual parallax shift of 42.93 mas provides a distance estimate of 76 light years. It is moving closer to the Sun with a heliocentric radial velocity of −65 km/s.[5] In about 328,000 years from now, the star will make its closest approach at a distance of around 17 ly (5.1 pc).[11]
This is a solar analog,[3] which means its measured properties are similar to those of the Sun. However, it is much older than the Sun with an estimated age of around 8.1 billion years.[5] The spectrum matches a stellar classification of G1 V,[4] indicating this is an ordinary G-type main-sequence star that is generating energy through hydrogen fusion at its core. The level of chromospheric activity is low, making it a candidate for a Maunder minimum event.[5]
HD 168009 has about the same mass as the Sun, but is 14% larger in radius.[7] It has a similar metallicity to the Sun – what astronomers term the abundance of elements other than hydrogen and helium – and is spinning with a rotation period of six days.[9] The star is radiating 1.43[8] times the Sun's luminosity from its photosphere at an effective temperature of 5,792 K.[5] It has been examined for an infrared excess that may indicate the presence of a circumstellar disk of dust, but no statistically significant excess was detected.[12][13]
Planetary system
In 2020, a candidate exoplanet was detected orbiting this star. With a minimum mass of 0.03 |♃|J}}}}}} (9.5 M⊕) and an orbital period of 15 days, this would most likely be a hot mini-Neptune.[14] The planet existence was confirmed in 2021.[15]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥0.0300+0.0038−0.0037 MJ | 0.1192+0.0017−0.0018 | 15.1479+0.0035−0.0037 | 0.121+0.110−0.082 | — | — |
References
- ↑ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific 99 (617): 695. doi:10.1086/132034. Bibcode: 1987PASP...99..695R. Constellation record for this object at VizieR.
- ↑ 2.0 2.1 2.2 2.3 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G. Gaia EDR3 record for this source at VizieR.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Soubiran, C.; Triaud, A. (May 2004), "The Top Ten solar analogs in the ELODIE library", Astronomy and Astrophysics 418 (3): 1089−1100, doi:10.1051/0004-6361:20035708, Bibcode: 2004A&A...418.1089S.
- ↑ 4.0 4.1 Mahdi, D. et al. (March 2016), "Solar twins in the ELODIE archive", Astronomy & Astrophysics 587: 9, doi:10.1051/0004-6361/201527472, A131, Bibcode: 2016A&A...587A.131M.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 Lubin, Dan et al. (March 2012), "Frequency of Maunder Minimum Events in Solar-type Stars Inferred from Activity and Metallicity Observations", The Astrophysical Journal Letters 747 (2): 6, doi:10.1088/2041-8205/747/2/L32, L32, Bibcode: 2012ApJ...747L..32L.
- ↑ 6.0 6.1 Takeda, Yoichi et al. (February 2005), "High-Dispersion Spectra Collection of Nearby F--K Stars at Okayama Astrophysical Observatory: A Basis for Spectroscopic Abundance Standards", Publications of the Astronomical Society of Japan 57 (1): 13–25, doi:10.1093/pasj/57.1.13, Bibcode: 2005PASJ...57...13T.
- ↑ 7.0 7.1 7.2 Fuhrmann, Klaus (July 2011), "Nearby stars of the Galactic disc and halo - V", Monthly Notices of the Royal Astronomical Society 414 (4): 2893−2922, doi:10.1111/j.1365-2966.2011.18476.x, Bibcode: 2011MNRAS.414.2893F.
- ↑ 8.0 8.1 McDonald, I. et al. (2012), "Fundamental parameters and infrared excesses of Hipparcos stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–357, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode: 2012MNRAS.427..343M.
- ↑ 9.0 9.1 Hempelmann, A. et al. (February 2016), "Measuring rotation periods of solar-like stars using TIGRE. A study of periodic CaII H+K S-index variability", Astronomy & Astrophysics 586: 19, doi:10.1051/0004-6361/201526972, A14, Bibcode: 2016A&A...586A..14H.
- ↑ "HD 168009". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+168009.
- ↑ Bailer-Jones, C. A. L. (March 2015), "Close encounters of the stellar kind", Astronomy & Astrophysics 575: 13, doi:10.1051/0004-6361/201425221, A35, Bibcode: 2015A&A...575A..35B.
- ↑ Sierchio, J. M. et al. (April 2014), "The Decay of Debris Disks around Solar-type Stars", The Astrophysical Journal 785 (1): 13, doi:10.1088/0004-637X/785/1/33, 33, Bibcode: 2014ApJ...785...33S.
- ↑ Ballering, Nicholas P. et al. (September 2013), "A Trend between Cold Debris Disk Temperature and Stellar Type: Implications for the Formation and Evolution of Wide-orbit Planets", The Astrophysical Journal 775 (1): 14, doi:10.1088/0004-637X/775/1/55, 55, Bibcode: 2013ApJ...775...55B.
- ↑ 14.0 14.1 Hirsch, Lea A. et al. (December 2020), "Understanding the Impacts of Stellar Companions on Planet Formation and Evolution: A Survey of Stellar and Planetary Companions within 25 pc", The Astronomical Journal 161 (3): 134, doi:10.3847/1538-3881/abd639, Bibcode: 2021AJ....161..134H.
- ↑ 15.0 15.1 Rosenthal, Lee J. et al. (2021), "The California Legacy Survey. I. A Catalog of 178 Planets from Precision Radial Velocity Monitoring of 719 Nearby Stars over Three Decades", The Astrophysical Journal Supplement Series 255 (1): 8, doi:10.3847/1538-4365/abe23c, Bibcode: 2021ApJS..255....8R
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