HD 70573

HD 70573

A light curve for V478 Hydrae, plotted from TESS data[1]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Hydra
Right ascension 08h 22m 49.95277s[2]
Declination +01° 51′ 33.5522″[2]
Apparent magnitude (V) 8.66-8.77[3]
Characteristics
Evolutionary stage main sequence
Spectral type G1/2V[4]
B−V color index 0.59[5]
Variable type BY Dra[3]
Astrometry
Radial velocity (Rv)20.16±0.22[2] km/s
Proper motion (μ) RA: −51.362±0.017 mas/yr[2]
Dec.: −49.047±0.013 mas/yr[2]
Parallax (π)16.9267 ± 0.0168 mas[2]
Distance192.7 ± 0.2 ly
(59.08 ± 0.06 pc)
Absolute magnitude (MV)+0.4[6]
Details
Mass1.0±0.1[6] M☉
Radius0.98+0.01
−0.03[7] R☉
Luminosity0.998±0.004[7] L☉
Surface gravity (log g)4.59±0.10[6] cgs
Temperature5,837+80
−51[7] K
Metallicity [Fe/H]−0.18±0.20[6] dex
Rotation3.296 days[6]
Rotational velocity (v sin i)14.7±1.0[6] km/s
Age2.3±2.1[8] Gyr
Other designations
V478 Hya, BD+02°1951, HD 70573, SAO 116694[9]
Database references
SIMBADdata

HD 70573 is a variable star in the equatorial constellation of Hydra. At a mean apparent visual magnitude of +8.7, this yellow-hued star is too dim to be visible to the naked eye. Based upon parallax measurements, it is located at a distance of 193 light years from the Sun, and is drifting further away with a radial velocity of 20.5 km/s. It is a candidate member of the proposed Hercules-Lyra Association of co-moving stars,[5] although this membership is disputed.[10]

This is a G-type main-sequence star with a stellar classification of G1/2V.[4] It is a BY Draconis variable that ranges in brightness from magnitude 8.66 down to 8.77 with a rotationally-modulated period of 3.296 days.[3] HD 70573 is generally considered to be a young star although estimates of its age vary from 60[11] million years to several billion years.[8] It has a projected rotational velocity of 15 km/s[6] and about the same mass, size, and luminosity as the Sun.

Planetary system

On March 19, 2007, an extrasolar planet was announced, having been discovered by the radial velocity method. As of 2007, this was the youngest host star discovered to have an orbiting planet.[6] However, a follow-up study by Soto et al. in 2015 failed to detect the planetary signal, so it remains unconfirmed.[12]

The system displays an infrared excess, which matches the black body signature of a debris disk orbiting 21.8 AU from the host star with a mean temperature of 60 K.[13]

The HD 70573 planetary system[6]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
b (unconfirmed) ≥6.1±0.4 MJ 1.76±0.05 851.8±11.6 0.4±0.1 — —

References

  1. ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
  2. ^ a b c d e 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.
  3. ^ a b c Samus, N. N.; et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 125853869.
  4. ^ a b Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars". Michigan Spectral Survey. 5. Bibcode:1999MSS...C05....0H.
  5. ^ a b López-Santiago, J.; et al. (2006). "The Nearest Young Moving Groups". The Astrophysical Journal. 643 (2): 1160–1165. arXiv:astro-ph/0601573. Bibcode:2006ApJ...643.1160L. doi:10.1086/503183. S2CID 119520529.
  6. ^ a b c d e f g h i Setiawan; et al. (2007). "Evidence for a Planetary Companion around a Nearby Young Star". The Astrophysical Journal Letters. 660 (2): L145–L148. arXiv:0704.0441. Bibcode:2007ApJ...660L.145S. doi:10.1086/518213. S2CID 18721503.
  7. ^ a b c 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.
  8. ^ a b Llorente de Andrés, F.; Chavero, C.; de la Reza, R.; Roca-Fàbrega, S.; Cifuentes, C. (October 2021). "The evolution of lithium in FGK dwarf stars. The lithium-rotation connection and the Li desert". Astronomy and Astrophysics. 654: A137. arXiv:2108.05852. Bibcode:2021A&A...654A.137L. doi:10.1051/0004-6361/202141339. ISSN 0004-6361.
  9. ^ "HD 70573". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-01-08.
  10. ^ Eisenbeiss, T.; et al. (August 2013). "The Hercules-Lyra association revisited. New age estimation and multiplicity study". Astronomy & Astrophysics. 556: 19. arXiv:1312.4045. Bibcode:2013A&A...556A..53E. doi:10.1051/0004-6361/201118362. S2CID 119275785. A53.
  11. ^ Meshkat, Tiffany; et al. (December 2017). "A Direct Imaging Survey of Spitzer-detected Debris Disks: Occurrence of Giant Planets in Dusty Systems". The Astronomical Journal. 154 (6): 21. arXiv:1710.04185. Bibcode:2017AJ....154..245M. doi:10.3847/1538-3881/aa8e9a. S2CID 42042014. 245.
  12. ^ Soto, M. G.; et al. (August 2015). "RAFT - I. Discovery of new planetary candidates and updated orbits from archival FEROS spectra". Monthly Notices of the Royal Astronomical Society. 451 (3): 3131–3144. arXiv:1505.04796. Bibcode:2015MNRAS.451.3131S. doi:10.1093/mnras/stv1144.
  13. ^ Cotten, Tara H.; Song, Inseok (July 2016). "A Comprehensive Census of Nearby Infrared Excess Stars". The Astrophysical Journal Supplement Series. 225 (1): 24. arXiv:1606.01134. Bibcode:2016ApJS..225...15C. doi:10.3847/0067-0049/225/1/15. S2CID 118438871. 15.


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