Astronomy:93 Leonis

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Short description: Star in the constellation Leo
93 Leonis
DQLeoLightCurve.png
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
Equinox J2000.0]] (ICRS)
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[2] mas
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]

See also

References

  1. Strassmeier, Klaus G.; Hall, Douglas S.; Boyd, Louis J.; Genet, Russell M. (January 1989). "Photometric Variability in Chromospherically Active Stars. III. The Binary Stars". The Astrophysical Journal Supplement Series 69: 141–215. doi:10.1086/191310. Bibcode1989ApJS...69..141S. https://ui.adsabs.harvard.edu/abs/1989ApJS...69..141S. Retrieved 18 January 2022. 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode2007A&A...474..653V. http://www.aanda.org/index.php?option=com_article&access=bibcode&Itemid=129&bibcode=2007A%2526A...474..653VFUL. 
  3. 3.0 3.1 Høg, E. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. Bibcode2000A&A...355L..27H. 
  4. 4.0 4.1 4.2 4.3 4.4 4.5 Hummel, C. A. et al. (July 1995). "Orbits of Small Angular Scale Binaries Resolved with the Mark III Interferometer". Astronomical Journal 110: 376. doi:10.1086/117528. Bibcode1995AJ....110..376H. 
  5. Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode1986EgUBV........0M. 
  6. 6.0 6.1 6.2 6.3 "* 93 Leo". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+93+Leo. 
  7. Halbwachs, J.-L.; Mayor, M.; Udry, S. (2012). "Double stars with wide separations in the AGK3 - I. Components that are themselves spectroscopic binaries". Monthly Notices of the Royal Astronomical Society 422 (1): 14–24. doi:10.1111/j.1365-2966.2012.20308.x. Bibcode2012MNRAS.422...14H. 
  8. Ian Ridpath's Startales - Leo the Lion