18 Delphini b
| Exoplanet | List of exoplanets | |
|---|---|---|
| Parent star | ||
| Star | 18 Delphini | |
| Constellation | Delphinus | |
| Right ascension | (α) | 20h 58m 26s |
| Declination | (δ) | +10° 50′ 21″ |
| Apparent magnitude | (mV) | 5.52 |
| Distance | 238 ± 11 ly (73.1 ± 3.5 pc) | |
| Spectral type | G6III | |
| Orbital elements | ||
| Semi-major axis | (a) | 2.6 AU (390 Gm) |
| 35 mas | ||
| Periastron | (q) | 2.4 AU (360 Gm) |
| Apastron | (Q) | 2.8 AU (420 Gm) |
| Eccentricity | (e) | 0.08 ± 0.01 |
| Orbital period | (P) | 993.3 ± 3.2 d (2.719 y) |
| Argument of periastron |
(ω) | 166.1 ± 6.5° |
| Time of periastron | (T0) | 2451672 ± 18 JD |
| Physical characteristics | ||
| Minimum mass | (m sin i) | 10.3 MJ |
| Discovery information | ||
| Discovery date | 19 February 2008 | |
| Discoverer(s) | Sato et al.[1] | |
| Discovery method | radial velocity | |
| Discovery site | Okayama Planet Search Program  Japan | |
| Discovery status | Published[1] | |
| Other designations | ||
| Database references | ||
| Extrasolar Planets Encyclopaedia | data | |
| SIMBAD | data | |
| Exoplanet Archive | data | |
| Open Exoplanet Catalogue | data | |
18 Delphini b (abbreviated 18 Del b), also named Arion, is an extrasolar planet approximately 238 light-years away in the constellation of Delphinus.
The 993-day period planet orbits the yellow giant star 18 Delphini. A very massive and dense planet with a minimum mass of 10.3 MJ it was discovered on February 19, 2008 by Sato.[1]
In July 2014 the International Astronomical Union launched a process for giving proper names to certain exoplanets and their host stars.[2] The process involved public nomination and voting for the new names.[3] In December 2015, the IAU announced the name Arion for this planet.[4] The winning name was submitted by the Tokushima Prefectural Jonan High School Science Club of Japan. Arion was a genius of poetry and music in ancient Greece. According to legend, his life was saved at sea by dolphins after attracting their attention by the playing of his kithara [5] ('Delphinus' is Latin for 'dolphin').
See also
References
- 1 2 3 Sato, Bun'ei; et al. (2008). "Planetary Companions around Three Intermediate-Mass G and K Giants: 18 Delphini, ξ Aquilae and HD 81688". Publications of the Astronomical Society of Japan. 60 (3): 539–550. arXiv:0802.2590
. Bibcode:2008PASJ...60..539S. doi:10.1093/pasj/60.3.539. - ↑ NameExoWorlds: An IAU Worldwide Contest to Name Exoplanets and their Host Stars. IAU.org. 9 July 2014
- ↑ NameExoWorlds The Process
- ↑ Final Results of NameExoWorlds Public Vote Released, International Astronomical Union, 15 December 2015.
- ↑ NameExoWorlds The Approved Names
- Jean Schneider (2011). "Notes for Planet 18 Del b". Extrasolar Planets Encyclopaedia. Retrieved 30 September 2011.
External links
- da Silva, L.; et al. (November 2006), "Basic physical parameters of a selected sample of evolved stars", Astronomy and Astrophysics, 458 (2): 609–623, arXiv:astro-ph/0608160, Bibcode:2006A&A...458..609D, doi:10.1051/0004-6361:20065105 – lists data about the star.
Coordinates: 
20h 58m 26s, +10° 50′ 21″