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] |
| Distance | 147.4 ± 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] |
| Distance | 145.8 ± 0.3 ly (44.7 ± 0.1 pc) |
| Orbit[4][5] | |
| Primary | 30 Arietis A |
| Companion | 30 Arietis BC |
| Period (P) | 34000 yr |
| Semi-major axis (a) | 40" (1670 AU) |
| Orbit[5] | |
| Primary | 30 Arietis B |
| Companion | 30 Arietis C |
| Period (P) | 80 yr |
| Semi-major axis (a) | 22.3 AU |
| Orbit[5] | |
| Primary | 30 Arietis B |
| Companion | 30 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 | |
| Mass | 1.31 ± 0.04[3] M☉ |
| Radius | 1.37 ± 0.03[3] R☉ |
| Age | 860±630[5] Myr |
| 30 Arietis Ba | |
| Mass | 1.16 ± 0.04[3] M☉ |
| Radius | 1.13 ± 0.03[3] R☉ |
| Age | 910±830[5] Myr |
| Details | |
| 30 Arietis Bb | |
| Mass | 147+41 −29[6] MJup |
| Other designations | |
| Database references | |
| SIMBAD | A |
| B | |
| Exoplanet Archive | data |
| 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
[edit]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
[edit]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
[edit]References
[edit]- ^ 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.
- ^ 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.
- ^ 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.
- ^ a b Whitney Clavin (2015). "Planet 'Reared' by Four Parent Stars". NASA. Archived from the original on 4 March 2016. Retrieved 4 March 2015.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ Jean Schneider (2011). "Notes for Planet 30 Ari B b". Extrasolar Planets Encyclopaedia. Retrieved 3 October 2011.
External links
[edit]- Image 30 Arietis
- Double stars
- NASA diagram of the 30 Ari System Archived 2016-02-20 at the Wayback Machine
