Lambda Ophiuchi

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Lambda Ophiuchi
Observation data
Epoch J2000      Equinox J2000
Constellation Ophiuchus
Right ascension 16h 30m 54.8229s[1]
Declination +01° 59′ 02.123″[1]
Apparent magnitude (V) 3.90[2]
Spectral type A0V+[2]
U−B color index +0.01[3]
B−V color index +0.01[3]
Variable type Suspected
Radial velocity (Rv) –13.5[4] km/s
Proper motion (μ) RA: –31.37 mas/yr
Dec.: –73.00 mas/yr
Parallax (π) 19.63 ± 1.34[1] mas
Distance 170 ± 10 ly
(51 ± 3 pc)
Rotational velocity (v sin i) 138[5] km/s
Other designations
lam Oph, 10 Oph, HR 6149, BD+02 3118, HD 148857, SAO 121658, HIP 80883.[2]

Lambda Ophiuchi (λ Oph, λ Ophiuchi) is a binary star[6] system in the constellation Ophiuchus. It has the traditional name Marfik (or "Marsik"), meaning "the elbow" in Arabic.

Lambda Ophiuchi belongs to spectral class A1V+A and has apparent magnitude +3.82. It is approximately 166 light years from Earth.


  1. ^ a b c Perryman, M. A. C.; et al. (April 1997). "The HIPPARCOS Catalogue". Astronomy & Astrophysics 323: L49–L52. Bibcode:1997A&A...323L..49P. 
  2. ^ a b c "lam Oph -- Variable Star". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2010-06-08. 
  3. ^ a b Johnson, H. L.; et al. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory 4 (99). Bibcode:1966CoLPL...4...99J. 
  4. ^ Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". In Batten, Alan Henry; Heard, John Frederick. Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. University of Toronto: International Astronomical Union. Bibcode:1967IAUS...30...57E. 
  5. ^ Royer, F.; Zorec, J.; Gómez, A. E. (February 2007). "Rotational velocities of A-type stars. III. Velocity distributions". Astronomy and Astrophysics 463 (2): 671–682. arXiv:astro-ph/0610785. Bibcode:2007A&A...463..671R. doi:10.1051/0004-6361:20065224. 
  6. ^ Lastennet, E.; Fernandes, J.; Lejeune, Th. (June 2002). "A revised HRD for individual components of binary systems from BaSeL BVRI synthetic photometry. Influence of interstellar extinction and stellar rotation". Astronomy and Astrophysics 388: 309–319. arXiv:astro-ph/0203341. Bibcode:2002A&A...388..309L. doi:10.1051/0004-6361:20020439. 

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