HD 117618

Last updated
HD 117618 / Dofida
Observation data
Epoch J2000       Equinox J2000
Constellation Centaurus
Right ascension 13h 32m 25.55543s [1]
Declination –47° 16′ 16.9091″ [1]
Apparent magnitude  (V)7.17 [2]
Characteristics
Spectral type G0 V [3]
B−V color index 0.603±0.010 [2]
Astrometry
Radial velocity (Rv)+1.60±0.76 [2]  km/s
Proper motion (μ)RA: +24.87 [1]   mas/yr
Dec.: −125.01 [1]   mas/yr
Parallax (π)26.34 ± 0.60  mas [1]
Distance 124 ± 3  ly
(38.0 ± 0.9  pc)
Absolute magnitude  (MV)4.27 [2]
Details [4]
Mass 1.10±0.02  M☉
Radius 1.17±0.04  R☉
Luminosity 1.6±0.1  L☉
Surface gravity (log g)4.34±0.03  cgs
Temperature 6,019±50  K
Metallicity [Fe/H]+0.03±0.01 [5]   dex
Rotational velocity (v sin i)3.67 [6]  km/s
Age 4.0±1.3  Gyr
Other designations
Dofida, CD−46° 8708, GC  18290, HD  117618, HIP  66047, SAO  224228 [7]
Database references
SIMBAD data
Extrasolar Planets
Encyclopaedia 		data

HD 117618, named Dofida by the IAU, [8] is a single, [9] yellow-hued star in the southern constellation of Centaurus. With an apparent visual magnitude of 7.17, [2] it is too faint to be visible to the naked eyes of a typical observer. The distance to this star, as determined from its annual parallax shift of 26.34±0.60  mas as seen from Earth's orbit, [1] is about 124  light years. It is moving further away with a heliocentric radial velocity of around +1.6 km/s. [2]

Contents

This star is similar to the Sun, being a G-type main-sequence star with a stellar classification of G0 V. [3] It is about 10% more massive and 17% larger than the Sun, with an estimated age of roughly four billion years [4] and a projected rotational velocity of 3.67 km/s. [6] The star is radiating 1.6 times the Sun's luminosity from its photosphere at an effective temperature of 6,019 K. [4]

Name

HD 117618, and its planet HD 117618b, were chosen as part of the 2019 NameExoWorlds campaign organised by the International Astronomical Union, which assigned each country a star and planet to be named. HD 117618 was assigned to Indonesia. The winning proposal named the star "Dofida" meaning our star in Nias language, and its planet "Noifasui" meaning revolve around in Nias language (derived from the word ifasui, meaning to revolve around, and no, indicating that the action occurred in the past and continued to the present time). [8]

Planetary system

In 2005, the Anglo-Australian Planet Search program announced the discovery of a low-mass planet in orbit around HD 117618. This object was found through measurements of radial velocity variation, which were larger than those produced by the intrinsic jitter of the host star. The best Keplerian fit to the data gave a periodicity of 25.8 days with an eccentricity of around 0.37 and a semimajor axis of 0.17  AU . The lower bound on the object's mass was estimated to be 0.16  MJ . [10] These values were subsequently refined, as shown in the table below. [11]

The HD 117618 planetary system [11]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b / Noifasui >0.178 ± 0.021  MJ 0.176 ± 0.01025.827±0.0190.42 ± 0.17——

See also

Related Research Articles

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References

  1. 1 2 3 4 5 6 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv: 0708.1752 , Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID   18759600.
  2. 1 2 3 4 5 6 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. 1 2 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. arXiv: astro-ph/0603770 . Bibcode:2006AJ....132..161G. doi:10.1086/504637. S2CID   119476992.
  4. 1 2 3 Bonfanti, A.; Ortolani, S.; Nascimbeni, V. (2016). "Age consistency between exoplanet hosts and field stars". Astronomy & Astrophysics. 585: A5, 14 pp. arXiv: 1511.01744 . Bibcode:2016A&A...585A...5B. doi:10.1051/0004-6361/201527297. S2CID   53971692.
  5. ↑ Adibekyan, V.; et al. (August 2016). "Abundance trend with condensation temperature for stars with different Galactic birth places". Astronomy & Astrophysics. 592: 12. arXiv: 1606.04714 . Bibcode:2016A&A...592A..87A. doi:10.1051/0004-6361/201628883. S2CID   56256991. A87.
  6. 1 2 Delgado Mena, E.; et al. (April 2015). "Li abundances in F stars: planets, rotation, and Galactic evolution". Astronomy & Astrophysics. 576: 24. arXiv: 1412.4618 . Bibcode:2015A&A...576A..69D. doi:10.1051/0004-6361/201425433. S2CID   56051637. A69.
  7. ↑ "HD 114837". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2018-07-05.
  8. 1 2 "Approved names (§ Indonesia)". Name Exo Worlds. IAU . Retrieved 18 January 2020.
  9. ↑ Raghavan, Deepak; et al. (July 2006), "Two Suns in The Sky: Stellar Multiplicity in Exoplanet Systems", The Astrophysical Journal, 646 (1): 523–542, arXiv: astro-ph/0603836 , Bibcode:2006ApJ...646..523R, doi:10.1086/504823, S2CID   5669768.
  10. ↑ Tinney, C. G.; et al. (2005). "Three Low-Mass Planets from the Anglo-Australian Planet Search". The Astrophysical Journal. 623 (2): 1171–1179. Bibcode:2005ApJ...623.1171T. CiteSeerX   10.1.1.491.2941 . doi:10.1086/428661. S2CID   12515735.
  11. 1 2 Butler, R. P.; et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal. 646 (1): 505–522. arXiv: astro-ph/0607493 . Bibcode:2006ApJ...646..505B. doi:10.1086/504701. hdl:2299/1103. S2CID   119067572.
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