HR 4458
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hydra |
| Right ascension | 11h 34m 29.487s[1] |
| Declination | –32° 49′ 52.82″[1] |
| Apparent magnitude (V) | 5.97[2]/15 |
| Characteristics | |
| Spectral type | K0 V[3] + DC8[4] |
| U−B color index | 0.325[2] |
| B−V color index | 0.80[2] |
| V−R color index | 0.44 |
| R−I color index | 0.40 |
| Astrometry | |
| Radial velocity (Rv) | –22.21[5] km/s |
| Proper motion (μ) | RA: –671.54[6] mas/yr Dec.: 823.85[6] mas/yr |
| Parallax (π) | 104.61 ± 0.37[6] mas |
| Distance | 31.2 ± 0.1 ly (9.56 ± 0.03 pc) |
| Details | |
| HR 4458 A | |
| Radius | 0.84[7] R☉ |
| Luminosity (bolometric) | 0.368[8] L☉ |
| Surface gravity (log g) | 4.59[9] cgs |
| Temperature | 5,241[9] K |
| Metallicity [Fe/H] | –0.37[9] dex |
| Rotational velocity (v sin i) | 6.79[10] km/s |
| Age | 4.6–5.8[11] Gyr |
| Other designations | |
| WD 1132-325: VB 04 | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
HR 4458 (289 G. Hydrae) is a binary star system in the constellation Hydra. At a distance of 31 light years, it is the closest star system to the solar system within this constellation. The primary is K-type main-sequence star of class K0. It has a common proper motion companion at an angular separation of 16.2″. This is a white dwarf star with a classification of DC8.[4]
The primary has been examined for the presence of an infrared excess, but none was detected.[8]
References
- 1 2 Zacharias, N.; et al. (2013). "The Fourth US Naval Observatory CCD Astrograph Catalog (UCAC4)". The Astronomical Journal. 145 (2). 44. arXiv:1212.6182
. Bibcode:2013AJ....145...44Z. doi:10.1088/0004-6256/145/2/44.Vizier catalog entry - 1 2 3 Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV data. Bibcode:1986EgUBV........0M.
- ↑ Gray, R. O.; et al. (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): 161–70. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637.
- 1 2 Holberg, J. B.; et al. (November 2013). "Where are all the Sirius-like binary systems?". Monthly Notices of the Royal Astronomical Society. 435 (3): 2077–2091. arXiv:1307.8047. Bibcode:2013MNRAS.435.2077H. doi:10.1093/mnras/stt1433.
- ↑ Nidever, David L.; et al. (August 2002). "Radial Velocities for 889 Late-Type Stars". The Astrophysical Journal Supplement Series. 141 (2): 503–522. arXiv:astro-ph/0112477. Bibcode:2002ApJS..141..503N. doi:10.1086/340570.
- 1 2 3 van Leeuwen, F. (2007). "Validation of the New Hipparcos Reduction". Astronomy and Astrophysics. 474 (2): 653–64. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
- ↑ Johnson, H. M.; Wright, C. D. (183). "Predicted infrared brightness of stars within 25 parsecs of the sun". Astrophysical Journal Supplement Series. 53 (2): 643–711. Bibcode:1983ApJS...53..643J. doi:10.1086/190905.
- 1 2 Eiroa, C.; et al. (July 2013). "DUst around NEarby Stars. The survey observational results". Astronomy & Astrophysics. 555: A11. arXiv:1305.0155. Bibcode:2013A&A...555A..11E. doi:10.1051/0004-6361/201321050.
- 1 2 3 Ramírez, I.; et al. (September 2012). "Lithium Abundances in nearby FGK Dwarf and Subgiant Stars: Internal Destruction, Galactic Chemical Evolution, and Exoplanets". The Astrophysical Journal. 756 (1): 46. arXiv:1207.0499. Bibcode:2012ApJ...756...46R. doi:10.1088/0004-637X/756/1/46.
- ↑ Martínez-Arnáiz, R.; et al. (September 2010). "Chromospheric activity and rotation of FGK stars in the solar vicinity. An estimation of the radial velocity jitter". Astronomy and Astrophysics. 520: A79. arXiv:1002.4391. Bibcode:2010A&A...520A..79M. doi:10.1051/0004-6361/200913725.
- ↑ Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008). "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics". The Astrophysical Journal. 687 (2): 1264–1293. arXiv:0807.1686. Bibcode:2008ApJ...687.1264M. doi:10.1086/591785.
External links
- "CD-32 8179 / HR 4458 AB". SolStation. Retrieved 2007-06-06.
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