HD 22781

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HD 22781
Observation data
Epoch J2000       Equinox J2000
Constellation Perseus
Right ascension 03h 40m 49.5246s [1]
Declination +31° 49′ 34.6489″ [1]
Apparent magnitude  (V)8.78 [2]
Characteristics
Evolutionary stage main-sequence star [3]
Spectral type K0 [2]
Astrometry
Radial velocity (Rv)8.26 [1]  km/s
Proper motion (μ)RA: 40.576 [1]   mas/yr
Dec.: −94.254 [1]   mas/yr
Parallax (π)30.6433 ± 0.1071  mas [4]
Distance 106.4 ± 0.4  ly
(32.6 ± 0.1  pc)
Details [5]
Mass 0.75±0.02  M☉
Radius 0.70±0.02  R☉
Surface gravity (log g)4.57±0.04  cgs
Temperature 5175±15  K
Metallicity [Fe/H]−0.35±0.02  dex
Rotational velocity (v sin i)1.73 [3]  km/s
Age 4.14±3.63  Gyr
Other designations
BD+31 630, Gaia DR2  217334764042444288, HD  22781, HIP  17187, TYC  2355-246-1, GSC  02355-00246, 2MASS J03404953+3149345 [1]
Database references
SIMBAD data

HD 22781, is a single star about 106  light-years away. It is a K-type main-sequence star. The star’s age is poorly constrained at 4.14±3.63 billion years, but is likely similar to that of the Sun. [5] HD 22781 is heavily depleted in heavy elements, having just 45% of Sun's concentration of iron, [2] yet is comparatively rich in carbon, having 90% of Sun`s abundance. [5]

An imaging survey in 2012 has failed to find any stellar companions, suggesting HD 22781 is a single star. [6]

Planetary system

In 2011 a transiting superjovian planet or brown dwarf b was detected on an extremely eccentric orbit. [3] It is located just outside of the conservative habitable zone of the parent star. [7] Planets around such metal-poor stars are rare; the only three known similar cases are HD 111232 and HD 181720. [8]

In 2012, a radial velocity data review indicated there are no additional giant planets in the system. [9]

The HD 22781 planetary system [3]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b ≥13.65±0.97  MJ 1.167±0.039528.07±0.140.8191±0.0023——

Related Research Articles

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.

HD 114762 is a triple star system approximately 125 light-years (38.2 pc) away in the constellation Coma Berenices. It consists of a yellow-white F-type main-sequence star (HD 114762 A) and two red dwarf companions (HD 114762 Ab & HD 114762 B) approximately 0.36 & 130 AU distant. Both are low-metal subdwarfs. Planets around such metal-poor stars are rare. A telescope or strong binoculars are needed to view the primary. HD 114762 had been used by scientists as a "standard star", one whose radial velocity is well established, but with the discovery of the spectroscopic companion HD 114762 Ab its usefulness as a standard has been called into question.

HD 17092 is a star in the constellation of Perseus. It has an orange hue but is visible only with binoculars or better equipment, having an apparent visual magnitude of 7.73. The distance to this star is approximately 750 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +5.5 km/s.

HD 111232 is a star in the southern constellation of Musca. It is too faint to be visible with the naked eye, having an apparent visual magnitude of 7.59. The distance to this star is 94.5 light years based on parallax. It is drifting away from the Sun with a radial velocity of +104 km/s, having come to within 14.1 light-years some 264,700 years ago. The absolute magnitude of this star is 5.25, indicating it would have been visible to the naked eye at that time.

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 149143, also called Rosalíadecastro, is a star with a close orbiting exoplanet in the Ophiuchus constellation. Its apparent visual magnitude is 7.89 and the absolute magnitude is 3.87. The system is located at a distance of 239 light years from the Sun based on parallax measurements, and it is drifting further away with a radial velocity of 12 km/s.

<span class="mw-page-title-main">HD 13189</span> Orange-hued star in the constellation Taurus

HD 13189 is a star with an orbiting companion in the northern constellation of Triangulum constellation. With an apparent visual magnitude of +7.57, it is too faint to be visible to the normal human eye. The distance to this system is approximately 1,590 light years based on parallax measurements, and it is drifting further away with a radial velocity of 25.39 km/s. In 2005, a planetary companion or brown dwarf was announced in orbit around this star.

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 131664 is an 8th magnitude star in the southern constellation of Apus with an orbiting brown dwarf or stellar companion. Parallax measurements by the Gaia space observatory provide an estimated distance of 172.5 light years from the Earth. The system is moving further away with a baseline heliocentric radial velocity of +35 km/s.

HD 139357 is a 6th magnitude K-type giant star located approximately 370 light years from Earth, visible in the constellation Draco. Its mass is four thirds that of the Sun but its radius is 11.47 times larger. However, despite being a giant star, it is only 3.07 billion years old, which is younger than the Sun.

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 Stanisław 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 181720 is star with an orbiting substellar companion in the southern constellation of Sagittarius. It is located at a distance of 196 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −45.4 km/s. The star has an absolute magnitude of 4.10, but at that distance it has an apparent visual magnitude of 7.84, which is too faint to be seen with the naked eye. It shows a high proper motion, traversing the celestial sphere at an angular rate of 0.444 arcsec yr−1.

HD 85390 is a star with an exoplanet companion in the southern constellation of Vela. It was given the proper name Natasha by Zambia during the 100th anniversary of the IAU. Natasha means "thank you" in many languages of Zambia. This star is too faint to be seen with the naked eye, having an apparent visual magnitude of 8.54. It is located at a distance of 109 light years from the Sun based on parallax, and is drifting further away with a radial velocity of 33 km/s.

HD 175167 is a star with an exoplanet companion in the southern constellation of Pavo. It is too faint to be visible with the naked eye at an apparent visual magnitude of 8.01. The system is located at a distance of 232 light-years from the Sun based on parallax measurements, and it is drifting further away with a radial velocity of 5 km/s. It shows a high proper motion, traversing the celestial sphere at an angular rate of 0.190 arcsec yr−1.

HD 109271 is a wide binary star system in the constellation of Virgo. The brighter member of the binary has a pair of orbiting exoplanets. With an apparent visual magnitude of 8.05, it cannot be seen with the naked eye. Parallax measurements made by Gaia put the star at a distance of 181 light-years away from the Sun, but it is drifting closer with a radial velocity of −5 km/s. The system shows a high proper motion, traversing the celestial sphere at an angular rate of 0.232 arcsec yr−1.

HD 167665 is a yellow-white hued star with a brown dwarf companion in the southern constellation of Sagittarius. With an apparent visual magnitude of 6.39, it is near the lower brightness limit for stars that are visible to the naked eye. Based upon an annual parallax shift of 32.4 mas as seen from Earth, it is located 101 light years from the Sun. The star is moving away from the Sun with a radial velocity of +8 km/s.

HD 217786 is a binary star system in the equatorial constellation of Pisces. With an apparent visual magnitude of 7.78, it requires binoculars or a small telescope to view. The system is located at a distance of 181 light-years from the Sun based on parallax, and is drifting further away with a radial velocity of +10 km/s. Kinematically, the star system belongs to the thin disk population of the Milky Way.

HD 207832 is a G-type main-sequence star. Its surface temperature is 5764±15 K. HD 207832 is slightly enriched compared to the Sun in its concentration of heavy elements, with a metallicity Fe/H index of 0.17±0.01 and is much younger at an age of 0.74±0.62 billion years. Kinematically, it belongs to the thin disk of the Milky Way.

HD 121056, or HIP 67851, is an aging giant star with a pair of orbiting exoplanets located in the southern constellation of Centaurus. This star is dimly visible to the naked eye with an apparent visual magnitude of 6.17. It is located at a distance of 209 light years from the Sun, based on parallax measurements, and is drifting further away with a radial velocity of 5.6 km/s.

HD 3443 is a binary system composed of medium-mass main sequence stars in the constellation of Cetus about 50 light years away.

References

  1. 1 2 3 4 5 6 "HD 22781". SIMBAD . Centre de données astronomiques de Strasbourg.
  2. 1 2 3 Maldonado, J.; Villaver, E.; Eiroa, C.; Micela, G. (2019), "Connecting substellar and stellar formation. The role of the host star's metallicity", Astronomy & Astrophysics, 624: A94, arXiv: 1903.01141 , Bibcode:2019A&A...624A..94M, doi:10.1051/0004-6361/201833827, S2CID   118934484
  3. 1 2 3 4 Díaz, Rodrigo F.; Santerne, Alexandre; Sahlmann, Johannes; Hébrard, Guillaume; Eggenberger, Anne; Santos, Nuno C.; Moutou, Claire; Arnold, Luc; Boisse, Isabelle; Bonfils, Xavier; Bouchy, François; Delfosse, Xavier; Desort, Morgan; Ehrenreich, David; Forveille, Thierry; Lagrange, Anne-Marie; Lovis, Christophe; Pepe, Francesco; Perrier, Christian; Queloz, Didier; Ségransan, Damien; Udry, Stéphane; Vidal-Madjar, Alfred (2012), "The SOPHIE search for northern extrasolar planets IV. Massive companions in the planet-brown dwarf boundary", Astronomy & Astrophysics, A113: 538, arXiv: 1111.1168 , Bibcode:2012A&A...538A.113D, doi:10.1051/0004-6361/201117935, S2CID   55322205
  4. ↑ 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.
  5. 1 2 3 Maldonado, J.; Villaver, E. (2017), "Searching for chemical signatures of brown dwarf formation", Astronomy & Astrophysics, 602: A38, arXiv: 1702.02904 , Bibcode:2017A&A...602A..38M, doi:10.1051/0004-6361/201630120, S2CID   56225222
  6. ↑ Ginski, C.; Mugrauer, M.; Seeliger, M.; Eisenbeiss, T. (2012), "A lucky imaging multiplicity study of exoplanet host stars", Monthly Notices of the Royal Astronomical Society, 421 (3): 2498–2509, arXiv: 1202.4586 , Bibcode:2012MNRAS.421.2498G, doi:10.1111/j.1365-2966.2012.20485.x, S2CID   118573795
  7. ↑ Agnew, Matthew T.; Maddison, Sarah T.; Thilliez, Elodie; Horner, Jonathan (2017), "Stable habitable zones of single Jovian planet systems", Monthly Notices of the Royal Astronomical Society, 471 (4): 4494–4507, arXiv: 1706.05805 , Bibcode:2017MNRAS.471.4494A, doi:10.1093/mnras/stx1449, S2CID   119227856
  8. ↑ Adibekyan, Vardan (2019), "Heavy Metal Rules. I. Exoplanet Incidence and Metallicity", Geosciences, 9 (3): 105, arXiv: 1902.04493 , Bibcode:2019Geosc...9..105A, doi: 10.3390/geosciences9030105 , S2CID   119089419
  9. ↑ Wittenmyer, Robert A.; Wang, Songhu; Horner, Jonathan; Tinney, C. G.; Butler, R. P.; Jones, H. R. A.; O'Toole, S. J.; Bailey, J.; Carter, B. D.; Salter, G. S.; Wright, D.; Zhou, Ji-Lin (2013), "Forever alone? Testing single eccentric planetary systems for multiple companions", The Astrophysical Journal Supplement Series, 208 (1): 2, arXiv: 1307.0894 , Bibcode:2013ApJS..208....2W, doi:10.1088/0067-0049/208/1/2, S2CID   14109907
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