Lambda Ophiuchi

Lambda Ophiuchi
Observation data
Epoch J2000      Equinox J2000
Constellation Ophiuchus
Right ascension 16h 30m 54.82314s[1]
Declination +01° 59′ 02.1209″[1]
Apparent magnitude (V) 3.82[2] 4.18 + 5.22 + 11.0)[3]
Characteristics
Spectral type A0V + A4V[4]
U−B color index +0.01[5]
B−V color index +0.022±0.014[2]
Variable type Suspected[6]
Astrometry
Radial velocity (Rv)−16.0±1.5[2] km/s
Proper motion (μ) RA: –30.98[1] mas/yr
Dec.: –73.42[1] mas/yr
Parallax (π)18.84 ± 0.55 mas[1]
Distance173 ± 5 ly
(53 ± 2 pc)
Absolute magnitude (MV)0.20[2]
Orbit[7]
Period (P)192 yr
Semi-major axis (a)0.91″
Eccentricity (e)0.611
Inclination (i)23.0°
Longitude of the node (Ω)53.3°
Periastron epoch (T)B 1939.7
Argument of periastron (ω)
(secondary)		157.5°
Details
A
Mass2.62±0.04[8] M☉
Luminosity76.0+5.1
−4.8[8] L☉
Temperature8,831+101
−102[8] K
Rotational velocity (v sin i)138[8] km/s
B
Mass1.90[9] M☉
C
Mass0.72[9] M☉
Other designations
λ Oph, 10 Oph, NSV 7784, BD+02°3118, HD 148857, HIP 80883, HR 6149, SAO 121658, ADS 10087, WDS 16309+0159[10]
Database references
SIMBADdata

λ Ophiuchi, Latinized as Lambda Ophiuchi, is a triple star system[3] in the equatorial constellation of Ophiuchus.[10] It has the traditional name Marfik /ˈmɑːrfɪk/,[11] which now applies exclusively to the primary component.[12] The system is visible to the naked eye as a faint point of light with an apparent visual magnitude of 3.82.[2] It is located approximately 173 light-years from the Sun, based on its parallax,[1] but is drifting closer with a radial velocity of –16 km/s.[2]

  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 e f Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Edwards1976 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference clpl4 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference orb was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference zorec2012 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference msc was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Kunitzsch was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference IAU-LSN was invoked but never defined (see the help page).