Observation data Epoch J2000.0 Equinox J2000.0 |
|
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Constellation | Hercules |
Right ascension | 16h 30m 29.620s |
Declination | +38° 20′ 50.31″ |
Apparent magnitude (V) | 8.15 |
Characteristics | |
Spectral type | G0IV |
Apparent magnitude (B) | 8.76 |
B−V color index | 0.611 |
Astrometry | |
Radial velocity (Rv) | –18.1 ± 0.4 km/s |
Proper motion (μ) |
RA: –76.27 ± 0.54 mas/yr Dec.: 53.07 ± 0.69 mas/yr |
Parallax (π) | 12.59 ± 0.70mas |
Distance | 260 ± 10 ly (79 ± 4 pc) |
Absolute magnitude (MV) | 3.65 ± 0.12 |
Details | |
Mass | 1.345 ± 0.020 M☉ |
Radius | 1.541 +0.046 −0.042 R☉ |
Luminosity | 3.03 +0.20 −0.18 L☉ |
Surface gravity (log g) | 4.189 +0.020 −0.021 cgs |
Temperature | 6147 ± 50 K |
Metallicity [Fe/H] | 0.36 ± 0.05 dex |
Rotational velocity (v sin i) | 6.0 ± 0.5 km/s |
Age | 2.6 +0.3 −0.2 Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Exoplanet Archive | data |
Extrasolar Planets Encyclopaedia |
data |
HD 149026, also named Ogma, is a yellow subgiant star approximately 260 light-years from the Sun in the constellation of Hercules. An extrasolar planet (designated HD 149026 b, later named Smertrios) is believed to orbit the star.
HD 149026 in the star's identifier in the Henry Draper Catalog. Following its discovery in 2005 the planet was designated HD 149026 b.
In July 2014 the International Astronomical Union launched a process for giving proper names to certain exoplanets and their host stars. The process involved public nomination and voting for the new names. In December 2015, the IAU announced the winning names were Ogma for this star and Smertrios for its planet.
The winning names based on those submitted by the Club d'Astronomie de Toussaint of France; namely 'Ogmios' and 'Smertrios'. Ogmios was a Gallo-Roman deity and Smertrios was a Gallic deity of war. The IAU substituted the name of Ogma, a deity of eloquence, writing, and great physical strength in the Celtic mythologies of Ireland and Scotland, and who may be related to Ogmios, because 'Ogmios' is the name of an asteroid (189011 Ogmios).
In 2016, the IAU organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. In its first bulletin of July 2016, the WGSN explicitly recognized the names of exoplanets and their host stars approved by the Executive Committee Working Group Public Naming of Planets and Planetary Satellites, including the names of stars adopted during the 2015 NameExoWorlds campaign. This star is now so entered in the IAU Catalog of Star Names.