18 Delphini

From Wikipedia, the free encyclopedia
Jump to: navigation, search
18 Delphini
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Delphinus
Right ascension 20h 58m 25.93s
Declination +10° 50' 21.43″
Apparent magnitude (V) 5.522
Absolute magnitude (V) 1.202
Distance 238.493 ly
(73.121 pc)
Spectral type G6III:
Other designations
Database references
SIMBAD data

18 Delphini (abbreviated 18 Del), also named Musica, is a yellow giant star of spectral type G6III situated approximately 238 light-years from Earth in the constellation of Delphinus. An extrasolar planet (designated 18 Delphini b, later named Arion) is believed to be orbiting the star.

Nomenclature[edit]

18 Delphini is the star's Flamsteed designation. Following its discovery the planet was designated 18 Delphini b. In July 2014 the International Astronomical Union launched a process for giving proper names to certain exoplanets and their host stars.[1] The process involved public nomination and voting for the new names.[2] In December 2015, the IAU announced the winning names were Musica for this star and Arion for its planet.[3]

The winning names were those submitted by the Tokushima Prefectural Jonan High School Science Club of Japan. 'Musica' is Latin for 'music'. 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 [4] ('Delphinus' is Latin for 'dolphin').

Planetary system[edit]

On February 19, 2008, a 10.3 Jupiter mass extrasolar planet was found to be orbiting the star.[5]

The 18 Delphini planetary system[5]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b (Arion) >10.3 MJ 2.6 993.3 ± 3.2 0.08 ± 0.01

References[edit]

External links[edit]

Coordinates: Sky map 20h 58m 26s, +10° 50′ 21″