HD 85512

Last updated
HD 85512
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

Position

HD 85512 lies in Vela, 3′32″ west of and 10′54″ north of LZ Velorum (HD 86005), a chromospherically active giant, variable star, at 2090 light years away, of orange-to-red color and similarly average magnitude. [7]

Planetary system

Artists's impression of HD 85512 b. Credit: ESO/M. Kornmesser. HD 85512 Planetary system.jpg
Artists's impression of HD 85512 b. Credit: ESO/M. Kornmesser.

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. [9] 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, [10] but with revised models of the habitable zone two years later it was found to be too hot to be potentially habitable. [11] 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. [12]

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 

The HD 85512 planetary system [9]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b (dubious)≥3.6 M🜨 0.26 ± 0.00558.43 ± 0.130.11 ± 0.1——

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<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.

<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 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.

<span class="mw-page-title-main">HD 7924</span> Star in the constellation Cassiopeia

HD 7924 is a single star located 55.5 light years away from the Sun in the northern constellation of Cassiopeia, near the northern constellation border with Cepheus. It has an orange hue and is only visible by means of binoculars or a telescope due to a low apparent visual magnitude of 7.167. The star is drifting closer to the Sun with a radial velocity of –22.7 km/s, and is expected to approach to within 9.3 light-years in around 711,700 years.

HD 190984, also known as HIP 99496, is a star located in the southern circumpolar constellation Pavo, the peacock. It has an apparent magnitude of 8.76, making it readily visible in small telescopes, but not to the naked eye. Based on parallax measurements from the Gaia spacecraft, the object is estimated to be 486 light years away from the Solar System. It appears to be receding with a heliocentric radial velocity of 20.3 km/s.

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 90156 is a star with an orbiting exoplanet in the constellation Hydra. Based on parallax measurements, it is located at a distance of 71.6 light years from the Sun. The system is drifting further away with a heliocentric radial velocity of 27 km/s. The apparent visual magnitude of this star is 6.92, which is places it near the lower limit of visibility to the naked eye. A survey in 2015 ruled out the existence of any stellar companions at projected distances above 5 AU.

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.

<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.

<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 39194 is a star located in the southern circumpolar constellation Mensa. It has an apparent magnitude of 8.07, making it readily visible in binoculars but not to the naked eye. The object is relatively close at a distance of 86 light years but is receding with a heliocentric radial velocity of 13.9 km/s.

HD 30669 is a yellowish-orange hued star located in the southern constellation Caelum, the chisel. It has an apparent magnitude of 9.11, making it readily visible in small telescopes but not to the naked eye. The object is relatively close at a distance of 188 light years, based on parallax measurements from Gaia DR3. Its distance from the Solar System is rapidly increasing, having a heliocentric radial velocity of 66 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. ↑ "LZ Velorum - Universe Guide". 25 January 2015.
  8. ↑ "Fifty New Exoplanets Discovered by HARPS". ESO Science Release. 12 September 2011. Retrieved 13 September 2011.
  9. 1 2 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 .
  10. ↑ Kaltenegger, L.; Udry, S.; Pepe, F. (2011). "A Habitable Planet around HD 85512?". arXiv: 1108.3561 [astro-ph.EP].
  11. ↑ 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.
  12. ↑ "False Starts: Potentially Habitable Exoplanets - Planetary Habitability Laboratory @ UPR Arecibo". Archived from the original on 2021-10-18. Retrieved 2020-11-15.

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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