HD 28185

Last updated
HD 28185
Observation data
Epoch J2000.0       Equinox J2000.0
Constellation Eridanus
Right ascension 04h 26m 26.323s [1]
Declination −10° 33′ 02.95″ [1]
Apparent magnitude  (V)+7.80 [2]
Characteristics
Evolutionary stage Main sequence/subdwarf
Spectral type G6.5IV-V [3]
B−V color index 0.750±0.010 [2]
Astrometry
Radial velocity (Rv)50.40±0.14 [1]  km/s
Proper motion (μ)RA: 84.070±0.018  mas/yr [1]
Dec.: −59.637±0.016  mas/yr [1]
Parallax (π)25.4868 ± 0.0207  mas [1]
Distance 128.0 ± 0.1  ly
(39.24 ± 0.03  pc)
Absolute magnitude  (MV)4.67 [2]
Details
Mass 1.0±0.1 [4]   M☉
Radius 1.15±0.03 [4]   R☉
Luminosity 1.18±0.01 [4]   L☉
Surface gravity (log g)4.33±0.03 [4]   cgs
Temperature 5,609±41 [4]   K
Metallicity [Fe/H]0.19±0.01 [2]   dex
Rotation 30 days[ citation needed ]
Age 4.8±4.4 [4]   Gyr
Other designations
BD–10°919, HD  28185, HIP  20723, SAO  149631, GSC  05317-00733 [5]
Database references
SIMBAD data

HD 28185 is a yellow dwarf star similar to the Sun located 128 light-years away from Earth in the constellation Eridanus. The designation HD 28185 refers to its entry in the Henry Draper catalogue. The star is known to possess one long-period extrasolar planet.

Contents

Characteristics

According to measurements from the Gaia spacecraft, HD 28185 has a parallax of 25.4868 milliarcseconds, [1] which corresponds to a distance of 39.24 parsecs (128.0 light-years ). Since the star is located further than 25 parsecs from Earth, it is not listed in the Gliese Catalogue of Nearby Stars. With an apparent magnitude of 7.81, the star is almost never visible with the naked eye, though it can be seen using binoculars.

HD 28185 is similar to the Sun in terms of mass, radius, and luminosity. The star is on the main sequence and is generating energy by fusing hydrogen in its core.[ citation needed ] The spectral type of G6.5IV-V implies HD 28185 is cooler than the Sun. Like the majority of extrasolar planet host stars, HD 28185 is metal-rich relative to the Sun, containing around 173% of the solar abundance of iron. The star rotates slower than the Sun, with a period of around 30 days, compared to 25.4 days for the Sun.

Based on the star's chromospheric activity, HD 28185 is estimated to have an age of around 2,900 million years. On the other hand, evolutionary models give an age of around 7,500 million years and a mass 0.99 times that of the Sun. [6] The higher luminosity and longer rotation period favour an older age for the star.

Planetary system

In 2001 an extrasolar planet similar in size to Jupiter designated HD 28185 b was discovered in orbit around the star with a period of 1.04 years. [6] [7] Unlike many long-period extrasolar planets, it has a low orbital eccentricity. [8] The planet experiences similar insolation to Earth, which has led to speculations about the possibilities for habitable moons. [9] [10] In addition, numerical simulations suggest that low-mass planets located in the gas giant's Trojan points would be stable for long periods. [11] The planet's existence was independently confirmed by the Magellan Planet Search Program in 2008. [12]

The star also shows evidence of a long-term radial velocity trend, which may indicate the presence of an additional outer companion. [13] In 2022, the presence of an outer companion, likely a brown dwarf, was confirmed using a combination of radial velocity and astrometry. [14]

The HD 28185 planetary system [14]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(years)		 Eccentricity Inclination Radius
b 7.07+1.29
−0.79  MJ 		1.035+0.042
−0.046		1.056+0.0001
−0.0002		0.055+0.004
−0.003		55.65+11.11
−12.00 ° 		—
c19.639+2.266
−2.137  MJ 		13.176+0.518
−0.689		47.688+0.802
−1.841		0.120+0.021
−0.022		57.650+8.146
−5.747 ° 		—

See also

Related Research Articles

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<span class="mw-page-title-main">HD 28185 b</span> Gas giant orbiting HD 28185

HD 28185 b is an extrasolar planet 128 light-years away from Earth in the constellation of Eridanus. The planet was discovered orbiting the Sun-like star HD 28185 in April 2001 as a part of the CORALIE survey for southern extrasolar planets, and its existence was independently confirmed by the Magellan Planet Search Survey in 2008. HD 28185 b orbits its sun in a circular orbit that is at the inner edge of its star's habitable zone.

Eta2 Hydri is a star in the southern constellation of Hydrus. The name is latinized from η2 Hydri and often catalogued as HD 11977. It is visible to the naked eye with an apparent visual magnitude of +4.68, and is one of the least variable stars known. The distance to Eta2 Hydri is approximately 221 light-years based on parallax measurements, but it is drifting closer to the Sun with a radial velocity of −18 km/s.

HD 102195 is an orange-hued star in the zodiac constellation of Virgo with a confirmed exoplanet companion. With an apparent visual magnitude of 8.07, the star is too faint to be seen with the naked eye. The distance to HD 102195 can be estimated from its annual parallax shift of 34.06 mas, yielding 95.8 light years. It is moving further away from the Earth with a heliocentric radial velocity of 1.85 km/s. This is a high proper motion star and a possible member of the η Cha stellar kinematic group.

HD 40979 is a triple star system in the northern constellation of Auriga. The combined brightness of this group lies below the typical limit of visibility to the naked eye at an apparent visual magnitude of 6.74. It is located at a distance of approximately 108 light years from the Sun based on parallax. The system is receding with a radial velocity of +32 km/s. It has a relatively high rate of proper motion, traversing the celestial sphere at the rate of 0.182″ per year.

HD 187085 is a yellow–hued star in the southern constellation of Sagittarius. It is too faint to be visible to the naked eye, having an apparent visual magnitude of +7.225. The star is located at a distance of approximately 1,010 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +18 km/s.

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HD 99109 is an orange-hued star with an exoplanetary companion in the constellation of Leo. It has an absolute visual magnitude of +9.10, which is too faint to be visible to the naked eye. The distance to this system is 179 light-years based on parallax, and it is drifting further away with a radial velocity of +33 km/s. The star is one and half degrees away from the celestial equator to the south.

HD 142022 is a binary star system located in the southernmost constellation of Octans. It is too faint to be visible to the naked eye, having an apparent visual magnitude of 7.70. The distance to this system is 112 light-years based on parallax, but it is drifting closer to the Sun with a radial velocity of −10 km/s.

HD 213240 is a possible binary star system in the constellation Grus. It has an apparent visual magnitude of 6.81, which lies below the limit of visibility for normal human sight. The system is located at a distance of 133.5 light years from the Sun based on parallax. The primary has an absolute magnitude of 3.77.

HD 162020 is a star in the southern constellation of Scorpius with a likely red dwarf companion. It has an apparent visual magnitude of 9.10, which is too faint to be visible to the naked eye. The distance to this system is 102 light-years based on stellar parallax. It is drifting closer to the Sun with a radial velocity of −27 km/s, and is predicted to come to within ~18 light-years in 1.1 million years.

HD 24040 is a star with two orbiting exoplanets in the equatorial constellation of Taurus. The star is too faint to be viewed with the naked eye, having an apparent visual magnitude of 7.50. Based on parallax measurements, it is located at a distance of 152 light years. However, it is drifting closer to the Sun with a radial velocity of −9.4 km/s.

BD+14 4559 is a star with an exoplanetary companion in the northern constellation of Pegasus. During the 2019 NameExoWorlds campaign, the star was named Solaris by Poland after a 1961 science fiction novel about an ocean-covered exoplanet by Polish writer Stanislaw Lem. With an apparent visual magnitude of 9.78, the star is too faint to be viewed with the naked eye. The system is located at a distance of 161 light-years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −44 km/s. It is a high proper motion star, traversing the celestial sphere at an angular rate of 0.234″ yr−1.

HD 164604 is a single star in the southern constellation of Sagittarius constellation. It has the proper name Pincoya, as selected in the NameExoWorlds campaign by Chile, during the 100th anniversary of the IAU. Pincoya is a female water spirit from southern Chilean mythology who is said to bring drowned sailors to the Caleuche so that they can live in the afterlife. A 2015 survey ruled out the existence of any additional stellar companions at projected distances from 13 to 340 astronomical units. It is known to host a single super-Jupiter exoplanet.

References

  1. 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.
  2. 1 2 3 4 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.
  3. ↑ Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Bubar, E. J.; McGahee, C. E.; O'Donoghue, A. A.; Knox, E. R. (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.
  4. 1 2 3 4 5 6 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.
  5. ↑ "HD 28185". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2023-12-14.
  6. 1 2 Santos, N.; et al. (2001). "The CORALIE survey for southern extra-solar planets VI. New long-period giant planets around HD 28185 and HD 213240". Astronomy and Astrophysics . 379 (3): 999–1004. arXiv: astro-ph/0106255 . Bibcode:2001A&A...379..999S. doi:10.1051/0004-6361:20011366. S2CID   59061741.
  7. ↑ "Exoplanets: The Hunt Continues!" (Press release). Garching, Germany: European Southern Observatory. April 4, 2001. Retrieved December 27, 2012.
  8. ↑ Butler, R. P.; et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal. 646 (1): 505–522. arXiv: astro-ph/0607493 . Bibcode:2006ApJ...646..505B. doi:10.1086/504701. S2CID   119067572.
  9. ↑ Mullen, L. (2001). "Extrasolar Planets with Earth-like Orbits". Archived from the original on 29 September 2006. Retrieved 22 July 2006.
  10. ↑ Jones, Barrie W.; Sleep, P. Nick; Underwood, David R. (2006). "Habitability of Known Exoplanetary Systems Based on Measured Stellar Properties". The Astrophysical Journal . 649 (2): 1010–1019. arXiv: astro-ph/0603200 . Bibcode:2006ApJ...649.1010J. doi:10.1086/506557. S2CID   119078585.
  11. ↑ Schwarz, R.; Dvorak, R.; Süli, Á.; Érdi, B. (2007). "Survey of the stability region of hypothetical habitable Trojan planets". Astronomy and Astrophysics . 474 (3): 1023–1029. Bibcode:2007A&A...474.1023S. doi: 10.1051/0004-6361:20077994 .
  12. ↑ Minniti, Dante; et al. (2009). "Low-Mass Companions for Five Solar-Type Stars From the Magellan Planet Search Program". The Astrophysical Journal . 693 (2): 1424–1430. arXiv: 0810.5348 . Bibcode:2009ApJ...693.1424M. doi:10.1088/0004-637X/693/2/1424. S2CID   119224845.
  13. ↑ Chauvin, G.; Lagrange, A.-M.; Udry, S.; Fusco, T.; Galland, F.; Naef, D.; Beuzit, J.-L.; Mayor, M. (2006). "Probing long-period companions to planetary hosts. VLT and CFHT near infrared coronographic imaging surveys". Astronomy and Astrophysics . 456 (3): 1165–1172. arXiv: astro-ph/0606166 . Bibcode:2006A&A...456.1165C. doi:10.1051/0004-6361:20054709. S2CID   15611548.
  14. 1 2 Feng, Fabo; Butler, R. Paul; et al. (August 2022). "3D Selection of 167 Substellar Companions to Nearby Stars". The Astrophysical Journal Supplement Series . 262 (21): 21. arXiv: 2208.12720 . Bibcode:2022ApJS..262...21F. doi: 10.3847/1538-4365/ac7e57 . S2CID   251864022.

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