HD 23079
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Reticulum |
| Right ascension | 03h 39m 43.09600s[1] |
| Declination | −52° 54′ 57.0174″[1] |
| Apparent magnitude (V) | 7.12[2] |
| Characteristics | |
| Spectral type | F9.5V[3] |
| B−V color index | 0.583±0.009[2] |
| Astrometry | |
| Radial velocity (Rv) | +0.648±0.0004[4] km/s |
| Proper motion (μ) | RA: −192.838 mas/yr[1] Dec.: −92.021 mas/yr[1] |
| Parallax (π) | 29.8633±0.0194 mas[1] |
| Distance | 109.22 ± 0.07 ly (33.49 ± 0.02 pc) |
| Absolute magnitude (MV) | 4.47[2] |
| Details | |
| Mass | 1.01±0.02[5] M☉ |
| Radius | 1.08±0.02[5] R☉ |
| Luminosity | 1.372±0.005[5] L☉ |
| Surface gravity (log g) | 4.37±0.02[6] cgs |
| Temperature | 6,003±36[5] K |
| Metallicity [Fe/H] | −0.12±0.01[2] dex |
| Rotation | 15.0±2.6[6] days |
| Rotational velocity (v sin i) | 1.281±0.160[7] km/s |
| Age | 5.1±1.0[5] Gyr |
| Other designations | |
| Tupi, CD–53°738, GC 4401, HD 23079, HIP 17096, SAO 233208, LTT 1739[8] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HD 23079, also named Tupi, is a star in the southern constellation of Reticulum. Since the star has an apparent visual magnitude of 7.12,[2] it is not visible to the naked eye, but at least in binoculars it should be easily visible. Parallax measurements give a distance estimate of 109 light-years from the Sun. It is slowly drifting further away with a radial velocity of +0.65 km/s.[4]
This object is an inactive F-type main sequence star with a stellar classification of F9.5V;[3] in between F8 and G0. This indicates it is generating energy through core hydrogen fusion. The star is similar to the Sun, but is slightly hotter and more massive.[9] It is about 5.1 billion years old[5] and it is spinning slowly with a projected rotational velocity of 1.3 km/s.[7] The metallicity of this star is below solar, meaning the abundance of elements other than hydrogen and helium is lower than in the Sun.[2]
Nomenclature
[edit]This was one of the systems selected to be named in the 2019 NameExoWorlds campaign during the 100th anniversary of the IAU, which assigned each country a star and planet to be named. This system was assigned to Brazil. The approved names were Tupi for the star and Guarani for planet b, named after the Tupi and Guarani indigenous peoples of Brazil.[10][11]
Planetary system
[edit]In October 2001, a giant planet orbiting the star was announced, detected by the radial velocity method.[12] The orbit of this object is similar to that of Mars, and the presence of such a large planet would have a strong impact on an Earth-like planet in the habitable zone of this Star.[9] Any Earthlike planet would have to exist either as an exomoon or Trojan planet of HD 23079 b.
With additional observations, the discovery of a second planet, HD 23079 c, was announced in 2025. This is a sub-Neptune mass planet orbiting closer to the star, with a period of only 5.75 days.[6]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| c | ≥8.1±0.8 M🜨 | — | 5.74894+0.00022 −0.00021 |
0.07+0.09 −0.05 |
— | — |
| b / Guarani | ≥2.66±0.05 MJ | 1.586±0.003[13] | 735.7±0.4 | 0.072+0.012 −0.011 |
— | — |
References
[edit]- ^ a b c d 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.
- ^ a b c d e f 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. S2CID 119257644.
- ^ a b 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.
- ^ a b Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d e f 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.
- ^ a b c d Delisle, J.-B.; Faria, J. P.; et al. (September 2025). "Architecture of planetary systems with and without outer giant planets I. Inner planet detections around HD 23079, HD 196067, and HD 86226". Astronomy & Astrophysics. arXiv:2509.26232.
- ^ a b Soto, M. G.; Jenkins, J. S. (July 2018). "Spectroscopic Parameters and atmosphEric ChemIstriEs of Stars (SPECIES). I. Code description and dwarf stars catalogue". Astronomy & Astrophysics. 615: 28. arXiv:1801.09698. Bibcode:2018A&A...615A..76S. doi:10.1051/0004-6361/201731533. A76.
- ^ "HD 23079". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-12-24.
- ^ a b Eberle, J.; Cuntz, M.; Quarles, B.; Musielak, Z. E. (October 2011). "Case studies of habitable Trojan planets in the system of HD 23079". International Journal of Astrobiology. 10 (4): 325–334. arXiv:1104.3092. Bibcode:2011IJAsB..10..325E. doi:10.1017/S1473550411000176. S2CID 118568335.
- ^ "International Astronomical Union | IAU". www.iau.org. Archived from the original on 2022-12-05. Retrieved 2020-01-02.
- ^ "Approved names". NameExoworlds. Retrieved 2020-01-02.
- ^ Tinney, C. G.; et al. (2002). "Two Extrasolar Planets from the Anglo-Australian Planet Search". The Astrophysical Journal. 571 (1): 528–531. arXiv:astro-ph/0111255. Bibcode:2002ApJ...571..528T. doi:10.1086/339916.
- ^ Wittenmyer, Robert A.; et al. (2020). "Cool Jupiters greatly outnumber their toasty siblings: occurrence rates from the Anglo-Australian Planet Search". Monthly Notices of the Royal Astronomical Society. 492 (1): 377–383. arXiv:1912.01821. Bibcode:2020MNRAS.492..377W. doi:10.1093/mnras/stz3436. S2CID 208617606.
External links
[edit]- "Notes for star HD 23079". Extrasolar Planets Encyclopaedia. Archived from the original on November 6, 2007.
- "NLTT 11572 – High proper-motion star". SIMBAD.
