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Mu Leonis

Mu Leonis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Leo
Right ascension 09h 52m 45.81654s
Declination +26° 00′ 25.0319″
Apparent magnitude (V) 3.88
Characteristics
Spectral type K2 IIIb CN1 Ca1
U−B color index +1.38
B−V color index +1.23
Astrometry
Radial velocity (Rv) 14.03±0.19 km/s
Proper motion (μ) RA: −217.31 mas/yr
Dec.: −54.26 mas/yr
Parallax (π) 26.28 ± 0.16mas
Distance 124.1 ± 0.8 ly
(38.1 ± 0.2 pc)
Absolute magnitude (MV) +0.83
Details
Mass 1.5±0.1 M
Radius 14 R
Luminosity 63 L
Surface gravity (log g) 2.5 cgs
Temperature 4,436 K
Metallicity [Fe/H] +0.17 dex
Rotational velocity (v sin i) 4.5 km/s
Age 3.35±0.70 Gyr
Other designations
Rasalas, μ Leo, 24 Leo, BD+26° 2019, HD 85503, HIP 48455, HR 3905, SAO 81064.
Database references
SIMBAD data

Mu Leonis (μ Leonis, abbreviated Mu Leo, μ Leo), also named Rasalas, is a star in the constellation of Leo. The apparent visual magnitude of this star is 3.88, which is bright enough to be seen with the naked eye. Based upon an annual parallax shift of 0.02628 arc seconds as measured by the Hipparcos satellite, this system is 124 light-years (38.1 parsecs) from the Sun. In 2014, an exoplanet was discovered to be orbiting the star.

μ Leonis (Latinised to Mu Leonis) is the star's Bayer designation.

It bore the traditional names Rasalas (Ras Elased Borealis) and Alshemali, both abbreviations of Ras al Asad al Shamaliyy, from the Arabic رأس الأسد الشمالي ra’s al-’asad aš-šamālī "the northern (star) of the lion's head". In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN approved the name Rasalas for this star on 12 September 2016 and it is now so entered in the IAU Catalog of Star Names.

Mu Leonis is an evolved K-type giant star with a stellar classification of K2 IIIb CN1 Ca1. The trailing notation indicates that, for a star of its type, it has stronger than normal absorption lines of cyanogen and calcium in its spectrum. It has around 1.5 times the Sun's mass, but has expanded to around 14 times the Sun's radius. Mu Leonis shines with 63 times the luminosity of the Sun from an outer atmosphere that has an effective temperature of 4,436 K. It is around 3.35 billion years old.


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Wikipedia

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