R Leonis

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Star
R Leonis
Einstern.jpg
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation lion
Right ascension 09 h 47 m 33.48 s
declination + 11 ° 25 ′ 43.8 ″
Apparent brightness 10.35 mag
Typing
B − V color index +1.30 
U − B color index −0.20 
R − I index +3.24 
Spectral class M6e-M9.5e
Variable star type M. 
Astrometry
Radial velocity (14.1 ± 0.6) km / s
parallax (14.06 ± 0.84)  mas
distance (232 ± 15)  ly
(71 ± 4)  pc
Visual absolute brightness M vis +6.09 mag
Proper movement 
Rec. Share: (−5.48 ± 2.32)  mas / a
Dec. portion: (−40.77 ± 1.01)  mas / a
Physical Properties
Dimensions (0.7)  M ☉
radius (300)  R ☉
Luminosity

(5500)  L ☉

Effective temperature (2900)  K
Other names
and catalog entries
Bonn survey BD + 12 ° 2096
Bright Star Catalog HR 3882 [1]
Henry Draper Catalog HD 84748 [2]
Hipparcos catalog HIP 48036 [3]
SAO catalog SAO 98769 [4]
Tycho catalog TYC 831-521-1 [5]
2MASS catalog 2MASS J09473348 + 1125436 [6]
Other names R Leonis
annotation
  1. ↑ Calculated from apparent brightness and distance.

R Leonis ( R Leo for short ) is a variable star of the Mira type in the western part of the constellation Leo . Its peculiarity was discovered as early as 1782 by the astronomer Julius August Koch in Danzig.

The apparent brightness of R Leonis fluctuates between +4.4 and +11.3 mag with a period of 310 days. At the maximum brightness, R Leonis is easy to see with the naked eye, at a minimum a telescope with at least 7 centimeters lens opening is necessary for its observation .

R Leonis belongs to the spectral class M8IIIe and is about 230 light years away from the sun .

Individual evidence

  1. ↑ a b R Leo. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed September 9, 2018 .
  2. ↑ a b Hipparcos catalog (ESA 1997)
  3. ↑ a b c Bright Star Catalog
  4. ↑ a b R Leo. In: VSX. AAVSO, accessed September 9, 2018 .
  5. ↑ Pulkovo radial velocities for 35493 HIP stars
  6. ^ Hipparcos, the New Reduction (van Leeuwen, 2007)
  7. ↑ Wiesemeyer et al .: Precessing planetary magnetospheres in SiO stars ?. First detection of quasi-periodic polarization fluctuations in R Leonis and V Camelopardalis . In: Astronomy & Astrophysics . 498, No. 3, 2009, pp. 801-810. arxiv : 0809.0359 . bibcode : 2009A & A ... 498..801W . doi : 10.1051 / 0004-6361 / 200811242 .
  8. ^ A b c E. De Beck, L. Decin, A. De Koter, K. Justtanont, T. Verhoelst, F. Kemper, KM Menten: Probing the mass-loss history of AGB and red supergiant stars from CO rotational line profiles . II. CO line survey of evolved stars: Derivation of mass-loss rate formulas . In: Astronomy and Astrophysics . 523, 2010, p. A18. arxiv : 1008.1083 . bibcode : 2010A & A ... 523A..18D . doi : 10.1051 / 0004-6361 / 200913771 .
  9. ↑ Cuno Hoffmeister, Gerold Richter, Wolfgang Wenzel Veränderliche Sterne, 2nd edition , JA Barth, Leipzig, 1984 p. 12