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

References

1. Beuermann, K.; Dreizler, S.; Hessman, F. V.; Schwope, A. D. (February 2014). "Evidence for an oscillation of the magnetic axis of the white dwarf in the polar DP Leonis". Astronomy and Astrophysics. 562: A63. arXiv:1401.1638. Bibcode:2014A&A...562A..63B. doi:10.1051/0004-6361/201323192. S2CID 118631556.
2. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
3. Samus, N. N.; et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 125853869. Retrieved 2021-11-30.
4. Duflot, M.; et al. (December 1995). "Radial velocities: The Wilson-Evans-Batten catalogue". Astronomy and Astrophysics Supplement. 114: 269. Bibcode:1995A&AS..114..269D.
5. Beuermann, K.; et al. (February 2011). "The giant planet orbiting the cataclysmic binary DP Leonis". Astronomy and Astrophysics. 526: 5. arXiv:1011.3905. Bibcode:2011A&A...526A..53B. doi:10.1051/0004-6361/201015942. S2CID 119184531. A53.
6. Schwope, A. D.; et al. (2002). "A multiwavelength timing analysis of the eclipsing polar DP Leo". Astronomy and Astrophysics. 392 (2): 541–551. arXiv:astro-ph/0111457. Bibcode:2002A&A...392..541S. doi:10.1051/0004-6361:20011651. S2CID 17284811.
7. "DP Leo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-03-25.
8. Qian, S.-B.; et al. (2010). "Detection of a Giant Extrasolar Planet Orbiting the Eclipsing Polar DP Leo". The Astrophysical Journal Letters. 708 (1): L66–L68. Bibcode:2010ApJ...708L..66Q. doi:10.1088/2041-8205/708/1/L66.
9. Biermann, P.; et al. (June 1985). "The new eclipsing magnetic binary system E 1114+182". Astrophysical Journal. 293: 303–320. Bibcode:1985ApJ...293..303B. doi:10.1086/163238.