DP Leonis
Star system in the constellation Leo
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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]
| 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.
| 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 | — | — |