DP Leonis

DP Leonis (abbreviated DP Leo) is a binary star system in the equatorial constellation of Leo. It is a variable star that ranges in apparent visual magnitude from 17.5 down to 19.^[3] The system is located at a distance of approximately 990 light-years from the Sun based on parallax.^[2] It is a cataclysmic variable star of the AM Herculis-type also known as polars. The system comprises an eclipsing white dwarf and red dwarf in tight orbit (nearly 1.5 hours) and an extrasolar planet.^[8] This eclipsing variable was discovered by P. Biermann and associates in 1982 as the optical counterpart to the EINSTEIN X-ray source E1114+182.^[9]

DP Leonis

A white-light light curve for DP Leonis, adapted from Beuermann et al. (2014)[1]
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Leo
Right ascension	11h 17m 15.92381s[2]
Declination	+17° 57′ 41.6804″[2]
Apparent magnitude (V)	17.5-19[3]
Characteristics
Variable type	AM Her[3]
Astrometry
Radial velocity (Rv)	0.0[4] km/s
Proper motion (μ)	RA: −28.700 mas/yr[2] Dec.: −1.444 mas/yr[2]
Parallax (π)	3.2781±0.3110 mas[2]
Distance	990 ± 90 ly (310 ± 30 pc)
Orbit
Period (P)	0.0623628426[5] yr
Eccentricity (e)	0.0 (fixed)
Inclination (i)	79.5[6]°
Details
White dwarf
Mass	0.6[6] M☉
Temperature	13,500[5] K
Donor star
Mass	0.09[6] M☉
Other designations
DP Leo,[7] X 11146+182[3]
Database references
SIMBAD	data
Exoplanet Archive	data

Planetary system

In 2010, Qian et al. announced the detection of a third body of planetary mass around the eclipsing binary system. The presence of a third body had already been suspected in 2002.^[6] The object is roughly 6 times more massive than Jupiter and is located 8.6 AU from the binary.

The DP Leonis planetary system^[5]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (years)	Eccentricity	Inclination	Radius
b	≥6.1 ± 0.5 MJ	8.2 ± 0.4	28.0 ± 2.0	0.39 ± 0.13	—	—

See also

• NN Serpentis
• QS Virginis
• Lists of exoplanets