Astronomy:HD 129445

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Short description: Star in the constellation Circinus
HD 129445
Observation data
Equinox J2000.0]] (ICRS)
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[1] mas/yr
Dec.: –57.069[1] mas/yr
Parallax (π)14.9136 ± 0.0147[1] mas
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 Archive129445 data
Extrasolar Planets
Encyclopaedia		data

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 visible 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 the 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. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A. 
  3. ↑ 3.0 3.1 Houk, Nancy (1979). Michigan catalogue of two-dimensional spectral types for the HD stars. 1. Ann Arbor, Michigan: Department of Astronomy, University of Michigan. Bibcode: 1978mcts.book.....H. 
  4. ↑ 4.0 4.1 4.2 4.3 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. doi:10.1051/0004-6361/201732209. A55. Bibcode: 2018A&A...614A..55A. 
  5. ↑ 5.0 5.1 5.2 5.3 5.4 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.
  6. ↑ 6.0 6.1 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. doi:10.1051/0004-6361/201016333. A8. Bibcode: 2011A&A...531A...8J. 
  7. ↑ "HD 129445". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+129445. 
  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. doi:10.1088/0004-637X/711/2/1229. Bibcode: 2010ApJ...711.1229A. 
  9. ↑ "Estrella del Anfitrión: HD 129445". Planet Quest. http://planetquest1.jpl.nasa.gov/atlas_espanol/atlas_profile.cfm?Planet=576. 
  10. ↑ "HD 129445". Exoplanets. http://media4.obspm.fr/exoplanets/base/etoile.php?nom=HD+129445. Retrieved 2010-02-12. 
  11. ↑ 11.0 11.1 Xiao, Guang-Yao et al. (May 2023). "The Masses of a Sample of Radial-Velocity Exoplanets with Astrometric Measurements". Research in Astronomy and Astrophysics 23 (5): 055022. doi:10.1088/1674-4527/accb7e. Bibcode: 2023RAA....23e5022X. 

Coordinates: Sky map 14h 46m 03.06s, −68° 45′ 45.9″



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