30 Arietis

30 Arietis

30 Arietis star system hierarchy
Observation data
Epoch J2000      Equinox J2000
Constellation Aries
30 Arietis A
Right ascension 02h 37m 00.5235s[1]
Declination +24° 38′ 49.9880″[1]
30 Arietis B
Right ascension 02h 36m 57.7449s[2]
Declination +24° 38′ 53.0026″[2]
Characteristics
Spectral type F5 V / F6 V[3]
B−V color index 0.410 / 0.510[3]
Astrometry
30 Arietis A
Proper motion (μ) RA: 136.862±0.137[1] mas/yr
Dec.: −15.188±0.141[1] mas/yr
Parallax (π)22.1261 ± 0.0726 mas[1]
Distance147.4 ± 0.5 ly
(45.2 ± 0.1 pc)
30 Arietis B
Proper motion (μ) RA: 141.411±0.083[2] mas/yr
Dec.: −10.677±0.086[2] mas/yr
Parallax (π)22.3641 ± 0.0516 mas[2]
Distance145.8 ± 0.3 ly
(44.7 ± 0.1 pc)
Orbit[4][5]
Primary30 Arietis A
Companion30 Arietis BC
Period (P)34000 yr
Semi-major axis (a)40"
(1670 AU)
Orbit[5]
Primary30 Arietis B
Companion30 Arietis C
Period (P)80 yr
Semi-major axis (a)22.3 AU
Orbit[5]
Primary30 Arietis B
Companion30 Arietis Bb
Period (P)335.1 ± 2.5 d
(0.917 ± 0.007 yr)
Semi-major axis (a)0.995 ± 0.012 AU
Eccentricity (e)0.289 ± 0.092
Inclination (i)4.14+0.96
−0.90°[6]°
Details
30 Arietis A
Mass1.31 ± 0.04[3] M☉
Radius1.37 ± 0.03[3] R☉
Age860±630[5] Myr
30 Arietis Ba
Mass1.16 ± 0.04[3] M☉
Radius1.13 ± 0.03[3] R☉
Age910±830[5] Myr
Details
30 Arietis Bb
Mass147+41
−29[6] MJup
Other designations
CCDM 02370+2439, WDS 02370+2439

30 Arietis A
BD+24°376, HD 16246, HIP 12189, HR 765, SAO 75471

30 Arietis B
BD+24°375, HD 16232, HIP 12184, HR 764, SAO 75470
Database references
SIMBADA
B
Exoplanet Archivedata
Data sources:
Hipparcos Catalogue,
CCDM (2002),
Bright Star Catalogue (5th rev. ed.)

30 Arietis (abbreviated 30 Ari) is a 6th-apparent-magnitude multiple star system[4] in the constellation of Aries. 30 Arietis is the Flamsteed designation. 30 Arietis A and B are separated by 38.1″ or about 1,500 AU at a distance of 130 light years away. The main components of both systems are both binaries with a composite spectra belonging to F-type main-sequence stars, meaning they are fusing hydrogen in their cores. The 30 Arietis system is 910 million years old, one fifth the age of the Sun.

Star system

30 Arietis A and B are separated by 38.1", corresponding to 1,500 AU at a distance of 130 light years. The pair are at almost the same distance, have very similar proper motions, and are considered almost certain to be gravitationally bound with a likely period around 34,000 years.[5] The main components of both systems are both binaries with a composite spectra belonging to F-type main-sequence stars, meaning they are fusing hydrogen in their cores.[3]

30 Arietis A is a spectroscopic binary with an orbital period of 1.1 days.[7] The primary Aa is an F-type main sequence star about 31% more massive than the Sun, while the companion Ab is a faint red dwarf only about 15% the mass of the Sun.

30 Arietis B has been reported to have a red dwarf companion at a distance of 22 AU[5] and another red dwarf Bb at about 1 AU.[3] In 2020, after the inclination of the planetary orbit was measured, the "planet" was found to fall in the mass range of a brown or red dwarf.[6] The more distant companion was referred to as C to distinguish it from Bb, and at about 0.5" it has been imaged using adaptive optics.[5]

30 Arietis Bb

30 Arietis Bb (sometimes abbreviated 30 Ari Bb) is a red dwarf which orbits the F-type main sequence star 30 Arietis Ba, located in a quintuple star system approximately 146 light years away in the constellation Aries. The red dwarf, initially believed to be a massive planet or brown dwarf, was announced in a paper published online on September 24, 2009. It was discovered by using precision radial velocity measurements from the echelle spectrograph installed on the Alfred-Jensch telescope in Karl Schwarzschild Observatory.[3] The star had a minimum mass of nearly 10 times that of Jupiter.[8] In 2020, after the inclination of the planetary orbit was measured to be just 4.14+0.96
−0.90°, the "planet" was found to fall in the mass range of red dwarf stars.[6]

See also

References

  1. ^ 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.
  2. ^ 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.
  3. ^ a b c d e f g h i Guenther, E. W.; et al. (2009). "A substellar component orbiting the F-star 30 Arietis B". Astronomy and Astrophysics. 507 (3): 1659–1665. arXiv:0912.4619. Bibcode:2009A&A...507.1659G. doi:10.1051/0004-6361/200912112. S2CID 55685116.
  4. ^ a b Whitney Clavin (2015). "Planet 'Reared' by Four Parent Stars". NASA. Archived from the original on 4 March 2016. Retrieved 4 March 2015.
  5. ^ a b c d e f g h Roberts Jr, Lewis C.; Tokovinin, Andrei; Mason, Brian D.; Riddle, Reed L.; Hartkopf, William I.; Law, Nicholas M.; Baranec, Christoph (2015). "Know the Star, Know the Planet. III. Discovery of Late-Type Companions to Two Exoplanet Host Stars". The Astronomical Journal. 149 (4): 118. arXiv:1503.01211. Bibcode:2015AJ....149..118R. doi:10.1088/0004-6256/149/4/118. S2CID 30908636.
  6. ^ a b c d Kiefer, F.; et al. (January 2021). "Determining the true mass of radial-velocity exoplanets with Gaia. Nine planet candidates in the brown dwarf or stellar regime and 27 confirmed planets". Astronomy & Astrophysics. 645 A7. arXiv:2009.14164. Bibcode:2021A&A...645A...7K. doi:10.1051/0004-6361/202039168. S2CID 221995447.
  7. ^ Morbey, C. L.; Brosterhus, E. B. (1974). "A Search for Spectroscopic Binaries from Published Radial Velocity Data". Publications of the Astronomical Society of the Pacific. 86 (512): 455. Bibcode:1974PASP...86..455M. doi:10.1086/129630. JSTOR 40675565.
  8. ^ Jean Schneider (2011). "Notes for Planet 30 Ari B b". Extrasolar Planets Encyclopaedia. Retrieved 3 October 2011.