HD 240237

HD 240237
Observation data
Epoch J2000      Equinox J2000
Constellation Cassiopeia
Right ascension 23h 15m 42.22361s[1]
Declination +58° 02 35.6654[1]
Apparent magnitude (V) 8.19
Characteristics
Spectral type K2III[2]
Details
Mass1.69 ± 0.42[2] M
Radius32 ± 1[2] R
Luminosity331[3] L
Temperature4361 ± 10[2] K
Metallicity [Fe/H]-0.26 ± 0.07[2] dex
Rotation≥1010 d[2]
Age~0.27 Gyr

HD 240237 is a red giant approximately 4,900 light-years away in the constellation Cassiopeia.[1] The star has an exoplanet orbiting around it every 745 days.

Nomenclature and history

The designation b, derives from the order of discovery. The designation of b is given to the first planet orbiting a given star, followed by the other lowercase letters of the alphabet.[4] In the case of HD 240237, there was only one planet, so only the letter b is used.

Planetary system

The star is known to host one planet, with a mass around 5 times that of Jupiter, roughly every 2 years with mild eccentricity.

The HD 240237 planetary system[2]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b 5.3 MJ 1.9 745.7 ± 13.8 0.4 ± 0.1

References

  1. 1 2 3 "HD 240237". SIMBAD Astronomical Database. Centre de Données astronomiques de Strasbourg. Retrieved 7 June 2014.
  2. 1 2 3 4 5 6 7 Gettel, S.; Wolszczan, A.; Niedzielski, A.; Nowak, G.; Adamów, M.; Zieliński, P.; Maciejewski, G. (2011). "Substellar-Mass Companions to the K-Giants HD 240237, BD +48 738 and HD 96127". The Astrophysical Journal. 745: 28. arXiv:1110.1641Freely accessible. doi:10.1088/0004-637X/745/1/28.
  3. http://www.hpcf.upr.edu/~abel/phl/hec_plots/hec_orbit/hec_orbit_HD_240237_b.png
  4. Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv:1012.0707Freely accessible [astro-ph.SR].
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