HD 129445

HD 129445
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Circinus
Right ascension 14h 46m 03.06521s[1]
Declination –68° 45′ 45.8797″[1]
Apparent magnitude (V) 8.80[2]
Characteristics
Spectral type G6 V[3]
Apparent magnitude (B) 9.556[2]
Apparent magnitude (J) 7.531±0.023[2]
Apparent magnitude (H) 7.243±0.027[2]
Apparent magnitude (K) 7.167±0.026[2]
B−V color index 0.756±0.002[2]
Astrometry
Radial velocity (Rv)+8.56±0.13[1] km/s
Proper motion (μ) RA: –197.892 mas/yr[1]
Dec.: –57.069 mas/yr[1]
Parallax (π)14.9136 ± 0.0147 mas[1]
Distance218.7 ± 0.2 ly
(67.05 ± 0.07 pc)
Absolute magnitude (MV)4.73[2]
Details[4]
Mass1.06+0.03
−0.05 M☉
Radius1.18±0.01[5] R☉
Luminosity1.229+0.005
−0.004[5] L☉
Surface gravity (log g)4.39±0.08 cgs
Temperature5,605+21
−34[5] K
Metallicity [Fe/H]0.36±0.10 dex
Rotational velocity (v sin i)1.4[6] km/s
Age4.94+3.77
−2.04 Gyr
Other designations
CD–68°1403, HD 129445, HIP 72203, PPM 360965, LTT 5856, NLTT 38236[7]
Database references
SIMBADdata
Exoplanet Archivedata

HD 129445 (HIP 72203; LTT 5856) is a star located in the southern constellation Circinus. It has an apparent magnitude of 8.80,[2] making it faintly visble in binoculars but not to the naked eye. The object is located relatively close at a distance of 219 light-years based on Gaia DR3 parallax measurements but it is drifting away with a spectroscopic radial velocity of 8.56 km/s.[1] It has an absolute magnitude of +4.73,[2] which is similar to the Sun's absolute magnitude of 4.83.

Physical characteristics

HD 129445 has a stellar classification of G6 V,[3] indicating that it is an ordinary G-type main-sequence star like our Sun, albeit a bit cooler. It has 106% the mass of the Sun[4] and 118% the radius of the Sun.[5] It radiates 1.23 times the luminosity of the Sun from its photosphere at an effective temperature of 5,605 K,[5] giving it a yellow hue when viewed in the night sky. HD 129445 is extremely metal enriched with an iron abundance more than twice of that of the Sun's[4] and it spins slowly with a projected rotational velocity of 1.4 km/s.[6] It is slightly older than the Sun at the age of 4.94 billion years.[4]

Planetary system

The star was observed by the Magellan Planet Search Program due to its absolute visual magnitude and high metallicity. The Magellan program conducted 17 doppler velocity measurements, which spans a full orbital period. The results led the program to detect a planet dubbed HD 129445 b.[8][9][10] In 2023, the inclination and true mass of HD 129445 b were determined via astrometry.[11]

The HD 129445 planetary system[11]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(years) 		Eccentricity Inclination Radius
b 2.51+1.1
−0.54 MJ 		2.984+0.039
−0.054 		4.933+0.093
−0.13 		0.572+0.087
−0.086 		52+24
−19 or 128+19
−24° 		—

See also

References

  1. ^ a b c d e f 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. ^ a b c d e f g h i Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
  3. ^ a b Houk, Nancy (1979). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 1. Ann Arbor, Michigan: Department of Astronomy, University of Michigan. Bibcode:1978mcts.book.....H.
  4. ^ a b c d Aguilera-Gómez, Claudia; et al. (June 2018). "Lithium abundance patterns of late-F stars: an in-depth analysis of the lithium desert". Astronomy & Astrophysics. 614: 15. arXiv:1803.05922. Bibcode:2018A&A...614A..55A. doi:10.1051/0004-6361/201732209. S2CID 62799777. A55.
  5. ^ a b c d e 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.
  6. ^ a b Jenkins, J. S.; et al. (July 2011). "Chromospheric activities and kinematics for solar type dwarfs and subgiants: analysis of the activity distribution and the AVR". Astronomy & Astrophysics. 531: 15. arXiv:1103.0584. Bibcode:2011A&A...531A...8J. doi:10.1051/0004-6361/201016333. S2CID 55800969. A8.
  7. ^ "HD 129445". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-03-22.
  8. ^ Arriagada, Pamela; et al. (2010). "Five Long-period Extrasolar Planets in Eccentric orbits from the Magellan Planet Search Program". The Astrophysical Journal. 711 (2): 1229–35. arXiv:1001.4093. Bibcode:2010ApJ...711.1229A. doi:10.1088/0004-637X/711/2/1229. S2CID 118682009.
  9. ^ "Estrella del Anfitrión: HD 129445". Planet Quest. Archived from the original on 2010-07-04. Retrieved 2010-02-12.
  10. ^ "HD 129445". Exoplanets. Archived from the original on 2010-03-17. Retrieved 2010-02-12.
  11. ^ a b Xiao, Guang-Yao; Liu, Yu-Juan; et al. (May 2023). "The Masses of a Sample of Radial-Velocity Exoplanets with Astrometric Measurements". Research in Astronomy and Astrophysics. 23 (5): 055022. arXiv:2303.12409. Bibcode:2023RAA....23e5022X. doi:10.1088/1674-4527/accb7e.