Nu Leonis

ν Leonis
Location of ν Leonis (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Leo
Right ascension 09h 58m 13.37557s[1]
Declination +12° 26′ 41.2865″[1]
Apparent magnitude (V) 5.15[2]
Characteristics
Spectral type B6 IV[3]
U−B color index −0.13[2]
B−V color index −0.04[2]
Astrometry
Radial velocity (Rv)+14.4[4] km/s
Proper motion (μ) RA: −25.66[1] mas/yr
Dec.: −15.56[1] mas/yr
Parallax (π)6.53 ± 0.24 mas[1]
Distance500 ± 20 ly
(153 ± 6 pc)
Absolute magnitude (MV)−0.66[5]
Orbit[6]
Period (P)137.2978 d
Eccentricity (e)0.7
Longitude of the node (Ω)293.7°
Periastron epoch (T)2419815.9 JD
Semi-amplitude (K1)
(primary)		20 km/s
Details
Mass3.37±0.05[7] M☉
Radius2.3[8] R☉
Luminosity244[7] L☉
Temperature9,552[9] K
Rotational velocity (v sin i)100[7] km/s
Other designations
ν Leo, 27 Leo, BD+13°2183, HD 86360, HIP 48883, HR 3937, SAO 98876[10]
Database references
SIMBADdata

ν Leonis, Latinised as Nu Leonis, is a binary star system in the zodiac constellation of Leo. It is faintly visible to the naked eye with an apparent visual magnitude of 5.15;[2] parallax measurements[1] indicate it is around 500 light years away. At this distance, the visual extinction from interstellar dust is 0.33 magnitudes.[11]

It is 0.05 degree north of the ecliptic, so it can be occulted by the moon or planets.

This is a single-lined spectroscopic binary system with an orbital period of 137.3 days and an eccentricity of 0.7.[6] The primary component is a B-type subgiant star with a stellar classification of B6 IV.[3] It has about 3.37 times the mass of the Sun,[7] 2.3 times the Sun's radius,[8] and radiates 244[7] times the luminosity of the Sun from an outer atmosphere with an effective temperature of 9,552 K.[9] The rotation rate is moderate with a projected rotational velocity of 100 km/s.[7] Little is known about the companion.[6]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Mermilliod1986 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Cowley1969 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference rgcrv was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Harmanec1985 was invoked but never defined (see the help page).
  7. ^ a b c d e f Cite error: The named reference Zorec2012 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference cadars was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference vanBelle2009 was invoked but never defined (see the help page).