HD 38858

Last updated
HD 38858
Observation data
Epoch J2000.0       Equinox J2000.0
Constellation Orion [1]
Right ascension 05h 48m 34.94026s [2]
Declination −04° 05′ 40.7218″ [2]
Apparent magnitude  (V)+5.97 [3]
Characteristics
Evolutionary stage main sequence [2]
Spectral type G4V [4]
U−B color index +0.10 [3]
B−V color index +0.64 [3]
Astrometry
Radial velocity (Rv)+31.2 [5] km/s
Proper motion (μ)RA: +61.427 [2] mas/yr
Dec.: −229.291 [2] mas/yr
Parallax (π)65.7446±0.0307  mas [2]
Distance 49.61 ± 0.02  ly
(15.210 ± 0.007  pc)
Absolute magnitude  (MV)+5.06 [6]
Details
Mass 0.886 [7]   M☉
Radius 0.9331±0.0162 [7]   R☉
Luminosity 0.7943±0.0101 [7]   L☉
Surface gravity (log g)4.36±0.06 [4]   cgs
Temperature 5,660±20 [4]   K
Metallicity [Fe/H]−0.27±0.03 [4]   dex
Rotational velocity (v sin i)2.61 [8]  km/s
Age 6.2 [9]   Gyr
Other designations
BD−04°1244, FK5 1155, GJ 1085, HD 38858, HIP 27435, LTT 2380, SAO 132554
Database references
SIMBAD data
Exoplanet Archive data

HD 38858 is a star in the Orion constellation. It is a G-type main-sequence star, located at a distance of about 50 light-years. It has an apparent magnitude of 5.97, therefore can be seen to the naked eye only in sufficiently dark skies.

The last observation of this system for a dust disc or comet belt was in 2009 by the Spitzer Space Telescope; a belt was inferred at 102 AU. [9] It has an inclination of 48◦. [10]

The star exhibit a magnetic activity cycle remarkably similar to that of Sun, with the period of 10.8 years. [11]

Planetary system

The 74 exocomet belts imaged by ALMA's REASONS survey, showing belts of all shapes, sizes and ages (REASONS comboplot full nonames).jpg
Debris disk with the REASONS survey [12]

The exoplanet HD 38858 b was discovered in 2011 in orbit in its host star's habitable zone, a zone in which Earth-like conditions (namely the presence of liquid water) on a planet's surface are possible. [13] [14] The planet is likely a gas giant, a type of planet which astronomers believe is unlikely to support life as it is currently understood. However, the planet could have a rocky natural satellite capable of sustaining an Earth-like environment. [15]

The existence of this planet was disputed since 2015 though, attributing the planetary signal to the frequency-domain alias of the star magnetic activity cycle, although the existence of another planet on the 198-day orbit is suspected. [11]

The HD 38858 planetary system [16]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b(disputed [11] )32 [17] M🜨 1.0376±0.0189407.15±4.28570.27±0.17——
Disk102 AU ——

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 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 Johnson, H. L.; Iriarte, B.; Mitchell, R. I.; Wisniewskj, W. Z. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory. 4 (99): 99. Bibcode:1966CoLPL...4...99J.
  4. 1 2 3 4 J. Maldonado; C. Eiroa; E. Villaver; B. Montesinos; A. Mora (2012). "Metallicity of solar-type stars with debris discs and planets". Astronomy & Astrophysics. 541: A40. arXiv: 1202.5884 . Bibcode:2012A&A...541A..40M. doi:10.1051/0004-6361/201218800. S2CID   46328823.
  5. ↑ Nordström, B.; et al. (May 2004). "The Geneva-Copenhagen survey of the Solar neighbourhood: Ages, metallicities, and kinematic properties of 14,000 F and G dwarfs". Astronomy and Astrophysics. 418 (3): 989–1019. arXiv: astro-ph/0405198 . Bibcode:2004A&A...418..989N. doi:10.1051/0004-6361:20035959. S2CID   11027621.
  6. ↑ Radick, Richard R.; Lockwood, G. Wesley; Henry, Gregory W.; Hall, Jeffrey C.; Pevtsov, Alexei A. (2018). "Patterns of Variation for the Sun and Sun-like Stars". The Astrophysical Journal. 855 (2): 75. Bibcode:2018ApJ...855...75R. doi: 10.3847/1538-4357/aaaae3 .
  7. 1 2 3 Boyajian, Tabetha S.; et al. (July 2013). "Stellar Diameters and Temperatures. III. Main-sequence A, F, G, and K Stars: Additional High-precision Measurements and Empirical Relations". The Astrophysical Journal. 771 (1): 40. arXiv: 1306.2974 . Bibcode:2013ApJ...771...40B. doi:10.1088/0004-637X/771/1/40. S2CID   14911430.
  8. ↑ 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" (PDF). Astronomy and Astrophysics. 520: A79. arXiv: 1002.4391 . Bibcode:2010A&A...520A..79M. doi:10.1051/0004-6361/200913725. S2CID   43455849. Archived from the original (PDF) on 2017-09-22. Retrieved 2018-11-04.
  9. 1 2 Wyatt, M. C.; et al. (2012). "Herschel imaging of 61 Vir: implications for the prevalence of debris in low-mass planetary systems". Monthly Notices of the Royal Astronomical Society . 424 (2): 1206. arXiv: 1206.2370 . Bibcode:2012MNRAS.424.1206W. doi: 10.1111/j.1365-2966.2012.21298.x . S2CID   54056835. citing Lawler et al. 2009, and recalculating its distance.
  10. ↑ John E. Krist; Karl R. Stapelfeldt; Geoffrey Bryden; Peter Plavchan (2012). "Hubble Space Telescope Observations of the HD 202628 Debris Disk". Astronomical Journal. 144 (2): 45. arXiv: 1206.2078 . Bibcode:2012AJ....144...45K. doi:10.1088/0004-6256/144/2/45. S2CID   40040285.
  11. 1 2 3 Flores, M.; González, J. F.; Jaque Arancibia, M.; Saffe, C.; Buccino, A.; López, F. M.; Ibañez Bustos, R. V.; Miquelarena, P. (2018). "HD 38858: A solar-type star with an activity cycle of ~10.8 yr". Astronomy & Astrophysics. 620: A34. arXiv: 1809.05581 . doi:10.1051/0004-6361/201833330. S2CID   126153522.
  12. ↑ Matrà, L.; Marino, S.; Wilner, D. J.; Kennedy, G. M.; Booth, M.; Krivov, A. V.; Williams, J. P.; Hughes, A. M.; Burgo, C. del (2025-01-15). "REsolved ALMA and SMA Observations of Nearby Stars (REASONS): A population of 74 resolved planetesimal belts at millimetre wavelengths". Astronomy and Astrophysics. 693. arXiv: 2501.09058 . Bibcode:2025A&A...693A.151M. doi:10.1051/0004-6361/202451397.
  13. ↑ "The Extrasolar Planet Encyclopaedia — HD 38858 b". Extrasolar Planets Encyclopaedia . Retrieved 2020-03-06.
  14. ↑ Cain, Fraser (2015-06-29). "What is the Habitable Zone?". Universe Today. Retrieved 2020-03-06.
  15. ↑ "Should We Look For Life on Gas-Giants?". Futurism. Retrieved 2020-03-06.
  16. ↑ "hd_38858_b". Extrasolar Planets Encyclopaedia . 2015.
  17. ↑ Wyatt; m sin i is 0.0961±0.012 MJ / 30.55±4.11 (which Wyatt knew from most current cited paper Mayor, "HARPS XXXIV", 2011). Wyatt has likely factored in the inclination but did not state this outright in the arXiv version of the paper.
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