18 Delphini b

Coordinates: Sky map 20h 58m 26s, +10° 50′ 21″
From Wikipedia, the free encyclopedia
18 Delphini b / Arion
Radial velocity changes over time of 18 Delphini caused by the orbit of 18 Delphini b.
Discovered bySato et al.[1]
Discovery siteOkayama Planet
Search Program

Discovery date19 February 2008
radial velocity
Orbital characteristics
2.6 AU (390,000,000 km)
Eccentricity0.08 ± 0.01
993.3 ± 3.2 d
2.719 y
2451672 ± 18
166.1 ± 6.5
Star18 Delphini

18 Delphini b (abbreviated 18 Del b), formally named Arion /əˈrən/,[2] is an extrasolar planet approximately 249 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 Bun'ei Sato.[1]

In July 2014, the International Astronomical Union launched NameExoWorlds, a process for giving proper names to certain exoplanets and their host stars.[3] The process involved public nomination and voting for the new names.[4] In December 2015, the IAU announced the name Arion for this planet.[5] 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[6] ('Delphinus' is Latin for 'dolphin').

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  1. ^ a b 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.
  2. ^ "Arion". Merriam-Webster.com Dictionary.
  3. ^ NameExoWorlds: An IAU Worldwide Contest to Name Exoplanets and their Host Stars. IAU.org. 9 July 2014
  4. ^ "NameExoWorlds The Process". Archived from the original on 2015-08-15. Retrieved 2015-09-05.
  5. ^ Final Results of NameExoWorlds Public Vote Released, International Astronomical Union, 15 December 2015.
  6. ^ "NameExoWorlds The Approved Names". Archived from the original on 2018-02-01. Retrieved 2015-12-17.

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