93 Leonis

93 Leonis

A visual band light curve for DQ Leonis. The main plot shows the brightness variation over several years, and the inset plot shows the periodic variation seen during 1985. Adapted from Strassmeier et al. (1989)[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Leo
Right ascension 11h 47m 59.13595s[2]
Declination +20° 13′ 08.1500″[2]
Apparent magnitude (V) 4.522[3]
Characteristics
Spectral type G5III + A7V[4]
U−B color index +0.28[5]
B−V color index +0.9 / +0.2[4]
Variable type RS CVn[6]
Astrometry
Radial velocity (Rv)0.750 ± 0.05[7] km/s
Proper motion (μ) RA: −145.49[2] mas/yr
Dec.: −4.34[2] mas/yr
Parallax (π)14.02 ± 0.23 mas[2]
Distance233 ± 4 ly
(71 ± 1 pc)
Absolute bolometric
magnitude
 (Mbol)
0.48 / 1.27[4]
Orbit[4]
Period (P)71.69 d
Semi-major axis (a)7.5±0.1 mas
Eccentricity (e)0
Inclination (i)50.1±0.5°
Longitude of the node (Ω)138±1°
Periastron epoch (T)JD 2447642.6 ± 0.2
Argument of periastron (ω)
(secondary)
Semi-amplitude (K1)
(primary)
29.67±0.29 km/s
Semi-amplitude (K2)
(secondary)
33.8±2.1 km/s
Details[4]
93 Leo A
Mass2.25±0.29 M
Radius9.1±0.5 R
Luminosity49.4±3.4 L
Temperature5,100±100 K
93 Leo B
Mass1.97±0.15 M
Radius2.7±0.2 R
Luminosity23.9±1.9 L
Temperature7,800±200 K
Other designations
DQ Leo, BD+21°2358, FK5 1304, HD 102509, HIP 57565, HR 4527, SAO 81998[6]
Database references
SIMBADdata

93 Leonis (93 Leo) is a binary star in the constellation Leo. Its apparent magnitude is 4.522.[3] Based on the system's parallax, 93 Leonis is located about 233 light-years (71 parsecs) away.[2]

93 Leonis is a double-lined spectroscopic binary. Two components are known to exist, because their spectral lines shift periodically, due to the Doppler effect. The two stars are a G-type red giant and an A-type main-sequence star.[4] They complete an orbit once every 71.69 days. The system is also known to be an RS Canum Venaticorum variable, due to its binarity.[6] For that reason, it has been given the variable star designation DQ Leonis.[6]

In Chinese astronomy, 93 Leonis is called 太子, Pinyin: Tàizǐ, meaning Crown Prince, because this star is marking itself and stand alone in Crown Prince asterism, Supreme Palace enclosure mansion (see : Chinese constellation).[8]

  1. ^ Cite error: The named reference Strassmeier was invoked but never defined (see the help page).
  2. ^ a b c d e f van Leeuwen, F.; et al. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
  3. ^ a b Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H.
  4. ^ a b c d e f Hummel, C. A.; et al. (July 1995). "Orbits of Small Angular Scale Binaries Resolved with the Mark III Interferometer". Astronomical Journal. 110: 376. Bibcode:1995AJ....110..376H. doi:10.1086/117528.
  5. ^ Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
  6. ^ a b c d "* 93 Leo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 15 July 2017.
  7. ^ Halbwachs, J.-L.; Mayor, M.; Udry, S. (2012). "Double stars with wide separations in the AGK3 - I. Components that are themselves spectroscopic binaries" (PDF). Monthly Notices of the Royal Astronomical Society. 422 (1): 14–24. Bibcode:2012MNRAS.422...14H. doi:10.1111/j.1365-2966.2012.20308.x.
  8. ^ Ian Ridpath's Startales - Leo the Lion