R Leonis

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R Leonis
Leo constellation map.svg
Red circle.svg
Location of R Leonis (circled)
Observation data
Epoch J2000.0        Equinox J2000.0
Constellation Leo
Right ascension 09h 47m 33.4840s [1]
Declination +11° 25′ 43.823″ [1]
Apparent magnitude  (V)4.4 - 11.3 [2]
Characteristics
Spectral type M6e-M8IIIe-M9.5e [2]
Apparent magnitude  (J)−0.7 [3]
B−V color index 1.26
Variable type Mira variable
Astrometry
Proper motion (μ)RA: 6.132 [1]   mas/yr
Dec.: −53.097 [1]   mas/yr
Parallax (π)14.0566 ± 0.8378  mas [1]
Distance 372  ly
(114 [4]   pc)
Details
Mass 0.7 [5]   M☉
Radius 320 –350 [6]   R☉
Luminosity 3,537 [4]   L☉
Temperature 2,930 –3,080 [6]   K
Other designations
R Leo, AAVSO  0942+11, BD+12°2096, HD  84748, HIP  48036, HR  3882, SAO  98769
Database references
SIMBAD data

R Leonis is a red giant Mira-type variable star located approximately 370 light years away in the constellation Leo.

Contents

The light curve of R Leonis from AAVSO V band data RLeoLightCurve.png
The light curve of R Leonis from AAVSO V band data

The apparent magnitude of R Leonis varies between 4.31 and 11.65 with a period of 312 days. At maximum it can be seen with the naked eye, while at minimum a telescope of at least 7 cm is needed. The star's effective temperature is estimated to be 2,930 –3,080  kelvins and radius spans 320 solar radii (220,000,000 kilometres ; 1.5 astronomical units ), [6] roughly Mars's orbital zone.

Possible planet

Artistic rendering of R Leonis's putative evaporating planetary companion R Leonis evaporating planet.png
Artistic rendering of R Leonis's putative evaporating planetary companion

In 2009 Wiesemeyer et al. [5] proposed that quasi-periodic fluctuations observed for the star R Leonis may be due to the presence of an evaporating substellar companion, probably an extrasolar planet. They have inferred a putative mass for the orbiting body of twice the mass of Jupiter, orbital period of 5.2 years and likely orbital separation of 2.7 astronomical units. If confirmed such a planetary object could likely be an evaporating planet, with a long comet-like trail as hinted by intense SiO maser emissions.

The R Leonis planetary system
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b(unconfirmed)≥2 MJ ≥2.718980——

References

  1. 1 2 3 4 5 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.
  2. 1 2 "GCVS Query=R Leo". General Catalogue of Variable Stars @ Sternberg Astronomical Institute, Moscow, Russia . Retrieved 2012-08-22.
  3. ↑ "V* R Leo". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2012-08-21.
  4. 1 2 McDonald, I.; De Beck, E.; Zijlstra, A. A.; Lagadec, E. (2018). "Pulsation-triggered dust production by asymptotic giant branch stars". Monthly Notices of the Royal Astronomical Society. 481 (4): 4984. arXiv: 1809.07965 . Bibcode:2018MNRAS.481.4984M. doi: 10.1093/mnras/sty2607 . S2CID   118969263.
  5. 1 2 Wiesemeyer; et al. (2009). "Precessing planetary magnetospheres in SiO stars?. First detection of quasi-periodic polarization fluctuations in R Leonis and V Camelopardalis". Astronomy and Astrophysics . 498 (3): 801–810. arXiv: 0809.0359 . Bibcode:2009A&A...498..801W. doi:10.1051/0004-6361/200811242. S2CID   14531031.
  6. 1 2 3 Fedele; et al. (2005). "The K -Band Intensity Profile of R Leonis Probed by VLTI/VINCI". Astronomy and Astrophysics . 431 (3): 1019–1026. arXiv: astro-ph/0411133 . Bibcode:2005A&A...431.1019F. doi:10.1051/0004-6361:20042013. S2CID   15500217.
  7. ↑ "Download Data". aavso.org. AAVSO. Retrieved 1 October 2021.
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