NGC 2423-3

NGC 2423-3

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Puppis
Right ascension	07h 37m 09s
Declination	-13° 54′ 24″
Apparent magnitude (V)	9.45
Absolute magnitude (V)	0.03
Distance	2498 ly (766 pc)
Spectral type	K-M III
Other designations
BD-13 2130, GSC 05409-02156, TYC 5409-2156-1, NGC 2423-3, NGC 2423 MMU 3, NGC 2423 SN 4
Database references
SIMBAD	data

NGC 2423-3 is a red giant star approximately 2498 light-years away in the constellation of Puppis. The star is part of the NGC 2423 open cluster (hence the name NGC 2423-3). The star has an apparent magnitude of nine and an absolute magnitude of zero, with a mass of 2.4 times the Sun. As of 2007, it has been confirmed that an extrasolar planet orbits the star.

Planetary system

NGC 2423-3 b is an exoplanet^[1] 10.6 times more massive than Jupiter, even more massive than Pi Mensae b, which has mass about 10.3 times Jupiter. Only the minimum mass is known since the orbital inclination is not known, so it is likely to be a brown dwarf instead, like NGC 4349-127 b. The planet orbits at 10.2 μpc, taking 1.956 years to orbit eccentrically around the star. Its eccentricity is about the same as Mercury, but less than Pluto. The planet has semi-amplitude of 71.5 m/s since if 10.6 M_J planet orbits at 2.1 AU from 2.4 M_S star.

This planet was discovered by Chad Lovis and Michel Mayor in July 2007. Lovis had also found three Neptune-mass planets orbiting HD 69830 in May 2006, also in Puppis.

The NGC 2423-3 system^[1]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity
b	>10.6 MJ	2.10	714.3 ± 5.3	0.21 ± 0.07

References

1. ^ ^{a b} C. Lovis and M. Mayor (2007). "Two substellar companions in the open clusters NGC 2423 and NGC 4349". Astronomy and Astrophysics 472 (2): 657–664. Bibcode 2007A&A...472..657L. doi:10.1051/0004-6361:20077375. http://www.aanda.org/articles/aa/abs/2007/35/aa7375-07/aa7375-07.html.  (web preprint)

External links

• "Notes for star NGC 2423 3". The Extrasolar Planets Encyclopaedia. http://exoplanet.eu/star.php?st=NGC+2423+3. Retrieved 2008-08-11. 

See also

• NGC 4349-127
• PSR B1620-26

Coordinates: 07^h 37^m 09^s, −13° 54′ 24″