HD 85512

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HD 85512
HD 85512.jpg
HD 85512 imaged by the Digitized Sky Survey
Observation data
Epoch J2000       Equinox J2000
Constellation Vela
Right ascension 09h 51m 07.05180s [1]
Declination −43° 30′ 10.0237″ [1]
Apparent magnitude  (V)7.66
Characteristics
Spectral type K6V [2]
U−B color index 1.12
B−V color index 1.18
V−R color index 0.71
Astrometry
Radial velocity (Rv)−9.78±0.12 [1]  km/s
Proper motion (μ)RA: 461.603  mas/yr [1]
Dec.: −471.880  mas/yr [1]
Parallax (π)88.6737 ± 0.0173  mas [1]
Distance 36.782 ± 0.007  ly
(11.277 ± 0.002  pc)
Absolute magnitude  (MV)7.39 [3]
Details [2] [4]
Mass 0.69  M☉
Radius 0.533 ± 0.04 [note 1]   R☉
Luminosity (bolometric)0.126 ± 0.008  L☉
Surface gravity (log g)4.604±0.017  cgs
Temperature 4404±10  K
Metallicity ([Si/H] dex) -0.02
Metallicity [Fe/H]-0.28  dex
Rotation 47.13 ± 6.98
Rotational velocity (v sin i)2.194±0.118 km/s
Age 5.61 ± 0.61  Gyr
Other designations
CD−42°5678, Gaia DR2  5412947081287925504, GJ  370, HD  85512, HIP  48331, LHS  2201, 2MASS J09510700-4330097 [5]
Database references
SIMBAD data

HD 85512 is a solitary K-type main-sequence star 36.8 light-years (11.3 parsecs ) away in the constellation Vela. It is about 1 billion years older than the Sun. It is extremely chromospherically inactive, only slightly more active than Tau Ceti. It exhibits a long-term variability [2] and was thought to host one low-mass planet, although this is now doubtful. [6]

Contents

Proposed planetary system

On August 19, 2011, a ≥3.6 Earth-mass planet was discovered using HARPS that is "just inside" the habitable zone, along with the inner planets of e (or 82 G.) Eridani, and HD 192310 c in Capricornus. These two other systems are closer to Earth than this system. [7] Modelling at the time of the discovery announcement found that the planet could be cool enough to host liquid water if it has more than 50% cloud coverage, [8] but with revised models of the habitable zone two years later it was found to be too hot to be potentially habitable. [9] For a time it ranked fifth-best for habitability in the Planetary Habitability Laboratory's Habitable Exoplanets Catalog, which later listed it in an article about "false starts" in the search for potentially habitable exoplanets. [10]

In 2023, a study reassessed the radial velocity data of HD 85512. A signal was detected with a period of 51 days, inconsistent with the previously published 58-day orbital period of HD 85512 b, but consistent with previous estimates of the stellar rotation period. This indicates that the signal is very likely to be caused by the stellar rotation, rather than an orbiting planet. [6] : 25–27  [6] : 44  Due to this, the NASA Exoplanet Archive now considers this planet as a false positive detection. [11]

Related Research Articles

Groombridge 1618 is a star in the northern constellation Ursa Major. With an apparent visual magnitude of +6.6, it lies at or below the threshold of stars visible to the naked eye for an average observer. It is relatively close to Earth, at 15.89 light-years (4.87 pc). This is a main sequence star of spectral type K7.5 Ve, having just 67% of the Sun's mass.

HD 93083 is an orange-hued star in the southern constellation of Antlia. It has the proper name Macondo, after the mythical village of the novel One Hundred Years of Solitude. The name was selected by Colombia during the IAU's NameExoWorlds campaign. The star has an apparent visual magnitude of 8.30, which is too faint to be visible to the naked eye. It is located at a distance of 93 light years from the Sun based on parallax. HD 93083 is drifting further away with a radial velocity of +43.65 km/s, having come to within 43 light-years some 484,000 years ago.

<span class="mw-page-title-main">HD 219134</span> Star in the constellation Cassiopeia

HD 219134 is a main-sequence star in the constellation of Cassiopeia. It is smaller and less luminous than the Sun, with a spectral class of K3V, which makes it an orange-hued star. HD 219134 is relatively close to our system, with an estimated distance of 21.34 light years. This star is close to the limit of apparent magnitude that can still be seen by the unaided eye. The limit is considered to be magnitude 6 for most observers. This star has a magnitude 9.4 optical companion at an angular separation of 106.6 arcseconds.

<span class="mw-page-title-main">HD 192310</span> Star in the constellation Capricornus

HD 192310 is a star in the southern constellation of Capricornus. It is located in the solar neighborhood at a distance of 28.7 light-years, and is within the range of luminosity needed to be viewed from the Earth with the unaided eye. HD 192310 is suspected of being a variable star, but this is unconfirmed.

HD 70642 is a star with an exoplanetary companion in the southern constellation of Puppis. It has an apparent visual magnitude of +7.17, which is too dim to be readily visible to the naked eye. The system is located at a distance of 95.5 light-years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of +49.3 km/s. It came to within 55.3 ly of the Solar System some 329,000 years ago.

Pi Mensae, also known as HD 39091, is a G-dwarf star in the constellation of Mensa. This star has a high proper motion. The apparent magnitude is 5.67, which can be visible to the naked eye in exceptionally dark, clear skies. It is nearly 60 light-years away. The star is slightly larger than the Sun in terms of mass, size, luminosity, temperature and metallicity, and is about 730 million years younger. It hosts three known planets.

HD 154345 is a star in the northern constellation of Hercules. With an apparent visual magnitude of +6.76 it is a challenge to view with the naked eye, but using binoculars it is an easy target. The distance to this star is 59.6 light years based on parallax, but it is drifting closer with a radial velocity of −47 km/s. At least one exoplanet is orbiting this star.

<span class="mw-page-title-main">HD 40307</span> Star in the constellation Pictor

HD 40307 is an orange (K-type) main-sequence star located approximately 42 light-years away in the constellation of Pictor, taking its primary name from its Henry Draper Catalogue designation. It is calculated to be slightly less massive than the Sun. The star has six known planets, three discovered in 2008 and three more in 2012. One of them, HD 40307 g, is a potential super-Earth in the habitable zone, with an orbital period of about 200 days. This object might be capable of supporting liquid water on its surface, although much more information must be acquired before its habitability can be assessed.

HD 60532 is a star with two orbiting exoplanets in the southern constellation of Puppis. The designation HD 60532 takes its name from the Henry Draper Catalogue. The system is located at a distance of 85.5 light years from the Sun, and is drifting further away with a radial velocity of 61 km/s. At that distance, the star has an apparent visual magnitude of 4.45, which is bright enough to be faintly visible to the naked eye. The motion of this system through space brought it within 10.3 light-years of the Sun some 408,600 years ago.

HD 45364 is a star in the southern constellation of Canis Major. It is too faint to be visible to the naked eye, having an apparent visual magnitude of 8.08. The distance to this system is 112 light years based on parallax. It is drifting further away from the Sun with a radial velocity of +16.4 km/s, having come within 49 light-years some 1.5 million years ago.

HD 148156 is a star with an orbiting exoplanet in the southern constellation of Norma. It is located at a distance of 186 light years away from the Sun, but is drifting closer with a radial velocity of –1.8 km/s. The star has an apparent visual magnitude of 7.69, which is too dim to be visible to the naked eye. A survey in 2015 ruled out the existence of any stellar companions at projected distances from 49 to 345 astronomical units.

<span class="mw-page-title-main">HD 10180</span> Star in the constellation Hydrus

HD 10180, also designated 2MASS J01375356-6030414, is a Sun-like star in the southern constellation Hydrus that is notable for its large planetary system. Since its discovery, at least six exoplanets have been observed orbiting it, and some studies have proposed up to nine potential planets, which would make it potentially the largest of all known planetary systems, including the Solar System.

HIP 57050, or GJ 1148, is a faint star with two orbiting exoplanets in the northern constellation of Ursa Major. Other designations for this star include LHS 2443, G 122-40, and Ross 1003. From a distance of 36 light years based on parallax measurements, it is drifting closer to the Sun with a radial velocity of -9 km/s. This is a faint star with an absolute magnitude of 11.64. At the distance of HIP 57050, the apparent visual magnitude is 11.86, which is much too faint to be seen with the naked eye. HD 164595 has a high proper motion, traversing the celestial sphere at an angular rate of 0.577″ yr−1.

HD 38858 is a G-type star, much like The Sun, with one detected planet. The planet, designated HD 38858 b, is about twice the mass of Uranus and orbits in the star's habitable zone.

HD 103774 is a star with a close orbiting planetary companion in the southern constellation of Corvus. With an apparent visual magnitude of 7.13, it is too faint to be readily visible to the naked eye. Parallax measurements provide a distance estimate of 184 light years from the Sun. It is drifting closer with a radial velocity of −3 km/s. The star has an absolute magnitude of 3.41.

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.

<span class="mw-page-title-main">HD 189567</span> Star in the constellation Pavo

HD 189567 is a star with a pair of orbiting exoplanets, located in the southern constellation of Pavo. It is also known as Gliese 776, CD-67 2385, and HR 7644. The star has an apparent visual magnitude of 6.07, which is bright enough for it to be dimly visible to the naked eye. It lies at a distance of 58 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −10.5 km/s.

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.

References

  1. 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.
  2. 1 2 3 Anglada-Escudé, Guillem; Butler, R. Paul (2012), "The HARPS-TERRA project. I. Description of the algorithms, performance, and new measurements on a few remarkable stars observed by HARPS", The Astrophysical Journal Supplement Series, 200 (2): 15, arXiv: 1202.2570 , Bibcode:2012ApJS..200...15A, doi:10.1088/0067-0049/200/2/15, S2CID   118528839
  3. ↑ 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.
  4. ↑ Spectroscopic Parameters and atmosphEric ChemIstriEs of Stars (SPECIES) I. Code description and dwarf stars catalogue Full table D.1
  5. ↑ "HD 85512". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-09-22.
  6. 1 2 3 Laliotis, Katherine; Burt, Jennifer A.; Mamajek, Eric E.; et al. (22 February 2023). "Doppler Constraints on Planetary Companions to Nearby Sun-like Stars: An Archival Radial Velocity Survey of Southern Targets for Proposed NASA Direct Imaging Missions". The Astronomical Journal. 165 (4): 176. arXiv: 2302.10310 . Bibcode:2023AJ....165..176L. doi: 10.3847/1538-3881/acc067 .
  7. ↑ Pepe, F.; et al. (2011). "The HARPS search for Earth-like planets in the habitable zone. I. Very low-mass planets around HD 20794, HD 85512, and HD 192310". Astronomy and Astrophysics. 534. A58. arXiv: 1108.3447 . Bibcode: 2011A&A...534A..58P . doi: 10.1051/0004-6361/201117055 .
  8. ↑ Kaltenegger, L.; Udry, S.; Pepe, F. (2011). "A Habitable Planet around HD 85512?". arXiv: 1108.3561 [astro-ph.EP].
  9. ↑ Kopparapu, Ravi Kumar; et al. (2013). "Habitable Zones Around Main-Sequence Stars: New Estimates". The Astrophysical Journal. 765 (2): 131. arXiv: 1301.6674 . Bibcode:2013ApJ...765..131K. doi:10.1088/0004-637X/765/2/131. S2CID   76651902.
  10. ↑ "False Starts: Potentially Habitable Exoplanets - Planetary Habitability Laboratory @ UPR Arecibo". Archived from the original on 2021-10-18. Retrieved 2020-11-15.
  11. ↑ "HD 85512 Overview". NASA Exoplanet Archive . Retrieved August 12, 2024.

Notes

  1. ↑ From , where is the radius, is the luminosity, is the effective surface temperature and is the Stefan–Boltzmann constant.
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