HR 4458

HR 4458
Location of 20 Crateris (circled in red)
Observation data
Epoch J2000      Equinox ICRS
Constellation Hydra
A
Right ascension 11h 34m 29.48644s
Declination −32° 49′ 52.8228″
Apparent magnitude (V) 5.97
B
Right ascension 11h 34m 30.47776s
Declination −32° 50′ 02.4048″
Apparent magnitude (V) 15
Characteristics
A
Evolutionary stage main sequence
Spectral type K0 V
U−B color index +0.325
B−V color index +0.80
B
Evolutionary stage white dwarf
Spectral type DC8
Astrometry
A
Radial velocity (Rv)−22.09±0.12 km/s
Proper motion (μ) RA: −670.230 mas/yr
Dec.: +822.399 mas/yr
Parallax (π)104.6133±0.0277 mas
Distance31.177 ± 0.008 ly
(9.559 ± 0.003 pc)
Absolute magnitude (MV)6.05
B
Proper motion (μ) RA: –701.802 mas/yr
Dec.: +828.928 mas/yr
Parallax (π)104.6570±0.0267 mas
Distance31.164 ± 0.008 ly
(9.555 ± 0.002 pc)
Absolute magnitude (MV)15
Orbit
Period (P)1,400+600
−510 yr
Semi-major axis (a)142+38
−37 au
Eccentricity (e)0.28+0.57
−0.22
Inclination (i)83.4+2.1
−7.1°
Details
HR 4458 A
Mass0.900+0.044
−0.045 M☉
Radius0.84 R☉
Luminosity (bolometric)0.368 L☉
Surface gravity (log g)4.59 cgs
Temperature5,241 K
Metallicity [Fe/H]−0.37 dex
Rotational velocity (v sin i)6.79 km/s
Age4.6–5.8 Gyr
HR 4458 B
Mass0.554±0.022 M☉
Luminosity (bolometric)0.000088 L☉
Surface gravity (log g)8.12 cgs
Temperature5,000 K
Age5.69 Gyr
Other designations
20 Crt, 289 G. Hya, CD−32°8179, GJ 432, HD 100623, HIP 56452, HR 4458, SAO 202583, LHS 308, LTT 4280, PLX 2678.00
B: VB 4, WD 1132−325
Database references
SIMBADA
B
ARICNSdata

HR 4458 (HD 100623) is a binary star system 31.18 light-years away in the equatorial constellation of Hydra. It has the Flamsteed designation 20 Crateris and the Gould designation 289 G. Hydrae; the former refers to the constellation Crater, since Flamsteed numbered the stars of Crater and the central portion of Hydra as a separate constellation from the other parts of Hydra. This object is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.97. It is moving closer to the Earth with a heliocentric radial velocity of −22 km/s.

The primary component is a K-type main-sequence star with a stellar classification of K0 V. It is around five billion years old with 90% of the Sun's mass and 84% of the Sun's radius. The star is radiating 37% of the Sun's luminosity from its photosphere at an effective temperature of 5,241 K. It has been examined for the presence of an infrared excess, but none was detected.

The secondary, designated VB 4, is a 15th-magnitude white dwarf of class DC8 sharing common proper motion with the primary. The orbital period of the pair is of 1,400 years, albeit with large uncertainty.

Notes

References

  1. ↑ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.
  2. 1 2 3 4 5 6 7 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 Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
  4. 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.
  5. 1 2 Holberg, J. B.; Oswalt, Terry D.; Sion, E. M. (2002). "A Determination of the Local Density of White Dwarf Stars". The Astrophysical Journal. 571 (1): 512–518. arXiv:astro-ph/0102120. Bibcode:2002ApJ...571..512H. doi:10.1086/339842.
  6. 1 2 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. S2CID 119476992.
  7. 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.
  8. ↑ Holmberg, J.; et al. (July 2009). "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics". Astronomy and Astrophysics. 501 (3): 941–947. arXiv:0811.3982. Bibcode:2009A&A...501..941H. doi:10.1051/0004-6361/200811191. S2CID 118577511.
  9. ↑ Reid, I. Neill; Hawley, Suzanne L.; Gizis, John E. (1995). "The Palomar/MSU Nearby-Star Spectroscopic Survey. I. The Northern M Dwarfs -Bandstrengths and Kinematics". The Astronomical Journal. 110: 1838. Bibcode:1995AJ....110.1838R. doi:10.1086/117655.
  10. 1 2 3 4 5 An, Qier; Brandt, Timothy D.; Brandt, G. Mirek; Venner, Alexander (October 2025). "Orbits and Masses for 156 Companions from Combined Astrometry and Radial Velocities, and a Validation of Gaia Non-single-star Solutions". The Astrophysical Journal Supplement Series. 280 (2): 61. arXiv:2508.08374. Bibcode:2025ApJS..280...61A. doi:10.3847/1538-4365/adfa99. ISSN 0067-0049.
  11. 1 2 Johnson, H. M.; Wright, C. D. (1983). "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.
  12. 1 2 3 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. S2CID 377244.
  13. 1 2 3 4 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. S2CID 119199829.
  14. ↑ 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. S2CID 43455849.
  15. 1 2 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. S2CID 27151456.
  16. ↑ Holberg, J. B.; Oswalt, T. D.; Sion, E. M.; McCook, G. P. (2016). "The 25 parsec local white dwarf population". Monthly Notices of the Royal Astronomical Society. 462 (3): 2295. arXiv:1606.01236. Bibcode:2016MNRAS.462.2295H. doi:10.1093/mnras/stw1357.
  17. ↑ Hollands, M. A.; Tremblay, P. -E.; Gänsicke, B. T.; Gentile-Fusillo, N. P.; Toonen, S. (2018). "The Gaia 20 pc white dwarf sample". Monthly Notices of the Royal Astronomical Society. 480 (3): 3942. arXiv:1805.12590. Bibcode:2018MNRAS.480.3942H. doi:10.1093/mnras/sty2057.
  18. 1 2 Bagnulo, S.; Landstreet, J. D. (2021). "New insight into the magnetism of degenerate stars from the analysis of a volume-limited sample of white dwarfs". Monthly Notices of the Royal Astronomical Society. 507 (4): 5902. arXiv:2106.11109. Bibcode:2021MNRAS.507.5902B. doi:10.1093/mnras/stab2046.
  19. ↑ "HD 100623". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved May 6, 2019.
  20. 1 2 Wagman, M. (August 1987). "Flamsteed's Missing Stars". Journal for the History of Astronomy. 18 (3): 215. Bibcode:1987JHA....18..209W. doi:10.1177/002182868701800305. S2CID 118445625.
  21. ↑ Gould, Benjamin Apthorp (1879). "Uranometria Argentina catalog of bright southern stars". Resultados del Observatorio Nacional Argentino en Cordoba. 1. Buenos Aires. Bibcode:1879RNAO....1.....G. Retrieved 2012-05-08.
  22. ↑ 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. S2CID 51814894.
  23. ↑ Rodriguez, David R.; et al. (2015). "Stellar multiplicity and debris discs: An unbiased sample". Monthly Notices of the Royal Astronomical Society. 449 (3): 3160. arXiv:1503.01320. Bibcode:2015MNRAS.449.3160R. doi:10.1093/mnras/stv483.