HD 4308

HD 4308
Observation data
Epoch J2000      Equinox ICRS
Constellation Tucana
Right ascension 00h 44m 39.26721s
Declination −65° 38′ 58.2777″
Apparent magnitude (V) 6.544±0.005
Characteristics
Evolutionary stage main sequence
Spectral type G6VFe-0.9
Apparent magnitude (B) 7.193
Apparent magnitude (V) 6.552
Apparent magnitude (J) 5.366±0.024
Apparent magnitude (H) 5.101±0.016
Apparent magnitude (K) 4.945±0.020
Astrometry
Radial velocity (Rv)+95.251±0.0162 km/s
Proper motion (μ) RA: +157.639 mas/yr
Dec.: −741.913 mas/yr
Parallax (π)45.3559±0.0178 mas
Distance71.91 ± 0.03 ly
(22.048 ± 0.009 pc)
Absolute magnitude (MV)4.83
Details
Mass0.95±0.05 M☉
Radius1.04±0.03 R☉
Luminosity1.03±0.01 L☉
Surface gravity (log g)4.38±0.02 cgs
Temperature5,714±61 K
Metallicity [Fe/H]−0.35±0.07 dex
Rotational velocity (v sin i)1.0±1.0 km/s
Age10.0+0.5
−1.0 Gyr
Other designations
CD−66°38, GC 897, GJ 31.5, GJ 9028, HD 4308, HIP 3497, SAO 248244, PPM 352003, LFT 71, LHS 1139, LPM 40, LTT 416, TYC 8847-598-1, GCRV 50662, 2MASS J00443925-6538581
Database references
SIMBADdata
Exoplanet Archivedata
ARICNSdata

HD 4308 is a single star with a planetary system in the southern constellation of Tucana. It has a yellow hue and is a challenge to view with the naked eye even under good seeing conditions, having an apparent visual magnitude of 6.54. This object is located at a distance of 72 light-years, as determined from parallax measurements. It is a population II star and is considered to be a member of the thick disk. The star is receding from the Sun with a radial velocity of +95 km/s.

Stellar properties

This is a Sun-like G-type main-sequence star with a stellar classification of G6VFe-0.9, where the suffix notation indicates an underabundance of iron in the spectrum. The age of the star is poorly constrained, with estimated ranging from 1.6 billion years up to 10 billion. It has 95% of the mass of the Sun but 104% of the Sun's radius. The star is radiating nearly the same luminosity as the Sun from its photosphere at an effective temperature of 5,714 K.

Planetary system

In 2005, a low-mass exoplanet was found in orbit around this star using the radial velocity method with the HARPS spectrograph. It is following a circular orbit close to its host star with a period of just 15.6 days. Unusual for a star with planets, HD 4308 has a metallicity lower than that of the Sun. Further radial velocity observations allowed two additional planets to be detected by 2025.

The HD 4308 planetary system
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination
(°)		 Radius
b ≥0.0442 MJ 0.115 15.56±0.02 0.00±0.01 — —
c ≥0.15±0.07 MJ — 850±25 0.47±0.34 — —
d ≥0.14±0.08 MJ — 1,500±60 0.37±0.30 — —

See also

References

  1. 1 2 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. XHIP record for this object at VizieR.
  2. 1 2 3 4 5 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  3. 1 2 3 4 5 6 Fuhrmann, K.; et al. (2017). "Multiplicity among Solar-type Stars". The Astrophysical Journal. 836 (1): 139. Bibcode:2017ApJ...836..139F. doi:10.3847/1538-4357/836/1/139.
  4. 1 2 Gray, R. O.; et al. (July 2006). "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample". The Astronomical Journal. 132 (1): 161–170. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637. S2CID 119476992.
  5. 1 2 Koen, C.; Kilkenny, D.; van Wyk, F.; Marang, F. (April 21, 2010). "UBV(RI)CJHK observations of Hipparcos-selected nearby stars". Monthly Notices of the Royal Astronomical Society. 403 (4): 1949–1968. Bibcode:2010MNRAS.403.1949K. doi:10.1111/j.1365-2966.2009.16182.x. hdl:10566/813.
  6. 1 2 3 Cutri, R. M.; et al. (June 2003). 2MASS All Sky Catalog of point sources. NASA/IPAC. Bibcode:2003tmc..book.....C.
  7. 1 2 Soubiran, C.; et al. (April 2013). "The catalogue of radial velocity standard stars for Gaia. I. Pre-launch release". Astronomy & Astrophysics. 552: 11. arXiv:1302.1905. Bibcode:2013A&A...552A..64S. doi:10.1051/0004-6361/201220927. S2CID 56094559. A64.
  8. 1 2 3 Bonfanti, A.; et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics. 575. A18. arXiv:1411.4302. Bibcode:2015A&A...575A..18B. doi:10.1051/0004-6361/201424951. S2CID 54555839.
  9. 1 2 Ge, Z. S.; et al. (December 2016). "Ages of 70 Dwarfs of Three Populations in the Solar Neighborhood: Considering O and C Abundances in Stellar Models". The Astrophysical Journal. 833 (2): 13. arXiv:1612.01622. Bibcode:2016ApJ...833..161G. doi:10.3847/1538-4357/833/2/161. S2CID 119190116. 161.
  10. 1 2 "HD 4308". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-11-05.
  11. ↑ Neves, V.; et al. (April 2009). "Chemical abundances of 451 stars from the HARPS GTO planet search program. Thin disc, thick disc, and planets". Astronomy and Astrophysics. 497 (2): 563–581. arXiv:0902.3374. Bibcode:2009A&A...497..563N. doi:10.1051/0004-6361/200811328. S2CID 7907201.
  12. 1 2 Udry, S.; et al. (2006). "The HARPS search for southern extra-solar planets V. A 14 Earth-masses planet orbiting HD 4308". Astronomy and Astrophysics. 447 (1): 361–367. arXiv:astro-ph/0510354. Bibcode:2006A&A...447..361U. doi:10.1051/0004-6361:20054084. S2CID 119078261.
  13. 1 2 Ferreira, Thiago; Yana Galarza, Jhon; et al. (December 2025). "Hidden Companions of the Early Milky Way I. New alpha-Enhanced Exoplanet Hosts". arXiv:2512.17072 [astro-ph.EP].