Astronomy:HD 85390
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Vela |
| Right ascension | 09h 50m 02.4969s[1] |
| Declination | –49° 47′ 24.9576″[1] |
| Apparent magnitude (V) | 8.54[2] |
| Characteristics | |
| Spectral type | K1.5V[3] |
| Apparent magnitude (B) | 9.395[2] |
| Apparent magnitude (J) | 7.012±0.024[2] |
| Apparent magnitude (H) | 6.612±0.033[2] |
| Apparent magnitude (K) | 6.491±0.023[2] |
| B−V color index | 0.855±0.003[2] |
| Astrometry | |
| Radial velocity (Rv) | 33.03±0.20[4] km/s |
| Proper motion (μ) | RA: 29.8018±0.0379[1] mas/yr Dec.: −60.245±0.058[1] mas/yr |
| Parallax (π) | 29.8018 ± 0.0379[1] mas |
| Distance | 109.4 ± 0.1 ly (33.56 ± 0.04 pc) |
| Absolute magnitude (MV) | 5.99[2] |
| Details | |
| Mass | 0.81±0.02 M☉[5] 0.813+0.043 −0.038[6] M☉ |
| Radius | 0.78±0.01 R☉[5] 0.816+0.010 −0.011[6] R☉ |
| Luminosity | 0.39±0.01[5] L☉ |
| Surface gravity (log g) | 4.56±0.02[5] cgs |
| Temperature | 5,170±17 K[5] 5,182±20[6] K |
| Metallicity [Fe/H] | –0.04[6] dex |
| Rotational velocity (v sin i) | 1.97±0.36[6] km/s |
| Age | 6.8±2.9 Gyr[5] 8.893+4.400 −4.017[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| Extrasolar Planets Encyclopaedia | data |
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.[8][9] This star is too faint to be seen with the naked eye, having an apparent visual magnitude of 8.54.[2] 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.[1]
The stellar classification of HD 85390 is K1.5V,[3] showing this to be a K-type main-sequence star. It is an older star with age estimates of 7–9 billion years, and is not considered chromospherically active.[10] The star is spinning with a projected rotational velocity of 2 km/s.[6] It is smaller, cooler, dimmer, and less massive than the Sun,[5] but the metallicity is near solar.[6]
Planetary system
The planet b was detected by the radial velocity method in 2011.[10] It is following an eccentric orbit at a distance of 1.4 astronomical unit|AU from the host star.[11] An additional planet in the system was suspected since 2013,[12] only to be refuted in 2019.[11]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b (Madalitso) | ≥0.099 ± 0.010 MJ | 1.373 ± 0.035 | 799.52 ± 2.41 | 0.50 ± 0.05 | — | — |
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G. Gaia EDR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 Gray, R.O. et al. (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. doi:10.1086/504637. Bibcode: 2006AJ....132..161G.
- ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 Bonfanti, A.; Ortolani, S.; Nascimbeni, V. (2016). "Age consistency between exoplanet hosts and field stars". Astronomy & Astrophysics 585: 14. doi:10.1051/0004-6361/201527297. A5. Bibcode: 2016A&A...585A...5B.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 Soto, M. G.; Jenkins, J. S. (2018). "Spectroscopic Parameters and atmosphEric ChemIstriEs of Stars (SPECIES). I. Code description and dwarf stars catalogue". Astronomy and Astrophysics 615: A76. doi:10.1051/0004-6361/201731533. Bibcode: 2018A&A...615A..76S.
- ↑ "HD 85390". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+85390.
- ↑ "Approved names" (in en). http://www.nameexoworlds.iau.org/final-results.
- ↑ "International Astronomical Union | IAU". https://www.iau.org/news/pressreleases/detail/iau1912/.
- ↑ 10.0 10.1 Mordasini, C. et al. (2011). "The HARPS search for southern extrasolar planets XXIV. Companions to HD 85390, HD 90156, and HD 103197: a Neptune analog and two intermediate-mass planets". Astronomy and Astrophysics 526: A111. doi:10.1051/0004-6361/200913521. Bibcode: 2011A&A...526A.111M.
- ↑ 11.0 11.1 11.2 Wittenmyer, Robert A.; Clark, Jake T.; Zhao, Jinglin; Horner, Jonathan; Wang, Songhu; Johns, Daniel (2019), "Truly eccentric. I. Revisiting eight single-eccentric planetary systems", Monthly Notices of the Royal Astronomical Society 484 (4): 5859–5867, doi:10.1093/mnras/stz290, Bibcode: 2019MNRAS.484.5859W
- ↑ Wittenmyer, Robert A. et al. (2013), "Forever alone? Testing single eccentric planetary systems for multiple companions", The Astrophysical Journal Supplement Series 208 (1): 2, doi:10.1088/0067-0049/208/1/2, Bibcode: 2013ApJS..208....2W
Coordinates: 
09h 50m 02.4969s, −49° 47′ 24.959″
 |  |
