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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
SIMBAD data

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]

System

The inner pair form a binary star [13] system with an orbital period of 192 years and an eccentricity of 0.611. [7] Both components are A-type main-sequence stars, indicating that they are generating energy through core hydrogen fusion. The brighter member of this pair, designated component A, is the primary for the system with a visual magnitude of 4.18 [3] and a stellar classification of A0V. [4] The secondary, component B, is magnitude 5.22 [3] and class A4V. [4]

Component C is magnitude 11.0 and lies at an angular separation of 119 ″ from the inner pair. [3] It has a common proper motion and is at approximately the same distance as the other two stars, [14] although any orbit would last for hundreds of thousands of years. [9] It has a mass 72% of the Sun's, a radius 58% of the Sun's, a temperature of about 4,157  K, and 7% of the Sun's luminosity. [14] It has an estimated spectral type of K6. [9]

Nomenclature

λ Ophiuchi is the system's Bayer designation. The designations of the three components as Lambda Ophiuchi A, B and C derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU). [15]

It bore the traditional name Marfik (or Marsik), from the Arabic مرفق marfiq "elbow". In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) [16] to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems. [17] It approved the name Marfik for the component Lambda Ophiuchi A on 12 September 2016 and it is now so included in the List of IAU-approved Star Names. [12]

References

  1. ^ a b c d e f Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv: 0708.1752. Bibcode: 2007A&A...474..653V. doi: 10.1051/0004-6361:20078357. S2CID  18759600.
  2. ^ a b c d e f Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv: 1108.4971. Bibcode: 2012AstL...38..331A. doi: 10.1134/S1063773712050015. S2CID  119257644.
  3. ^ a b c d e Eggleton, P. P.; Tokovinin, A. A. (2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869. arXiv: 0806.2878. Bibcode: 2008MNRAS.389..869E. doi: 10.1111/j.1365-2966.2008.13596.x. S2CID  14878976.
  4. ^ a b c Edwards, T. W. (1976). "MK classification for visual binary components". The Astronomical Journal. 81: 245. Bibcode: 1976AJ.....81..245E. doi: 10.1086/111879.
  5. ^ Johnson, H. L.; et al. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory. 4 (99): 99. Bibcode: 1966CoLPL...4...99J.
  6. ^ Samus, N. N.; et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1. 61 (1): 80–88. Bibcode: 2017ARep...61...80S. doi: 10.1134/S1063772917010085. S2CID  125853869.
  7. ^ a b Heintz, W. D.; Strom, C. (1993). "The visual binary Lambda Ophiuchi". Astronomical Society of the Pacific. 105 (685): 293. Bibcode: 1993PASP..105..293H. doi: 10.1086/133145. S2CID  121998591.
  8. ^ a b c d Zorec, J.; et al. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics. 537: A120. arXiv: 1201.2052. Bibcode: 2012A&A...537A.120Z. doi: 10.1051/0004-6361/201117691. S2CID  55586789.
  9. ^ a b c d A. Tokovinin. "HR 6149". Multiple Star Catalogue.
  10. ^ a b "lam Oph". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-20.
  11. ^ Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN  978-1-931559-44-7.
  12. ^ a b "Naming Stars". IAU.org. Retrieved 16 December 2017.
  13. ^ 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. S2CID  14376211.
  14. ^ a b Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv: 1804.09365. Bibcode: 2018A&A...616A...1G. doi: 10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  15. ^ Hessman, F. V.; et al. (2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv: 1012.0707 [ astro-ph.SR].
  16. ^ IAU Working Group on Star Names (WGSN), International Astronomical Union, retrieved 22 May 2016.
  17. ^ "WG Triennial Report (2015–2018) – Star Names" (PDF). p. 5. Retrieved 2018-07-14.

External links

Retrieved from " https://en.wikipedia.org/?title=Lambda_Ophiuchi&oldid=1170090547"
From Wikipedia, the free encyclopedia
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
SIMBAD data

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]

System

The inner pair form a binary star [13] system with an orbital period of 192 years and an eccentricity of 0.611. [7] Both components are A-type main-sequence stars, indicating that they are generating energy through core hydrogen fusion. The brighter member of this pair, designated component A, is the primary for the system with a visual magnitude of 4.18 [3] and a stellar classification of A0V. [4] The secondary, component B, is magnitude 5.22 [3] and class A4V. [4]

Component C is magnitude 11.0 and lies at an angular separation of 119 ″ from the inner pair. [3] It has a common proper motion and is at approximately the same distance as the other two stars, [14] although any orbit would last for hundreds of thousands of years. [9] It has a mass 72% of the Sun's, a radius 58% of the Sun's, a temperature of about 4,157  K, and 7% of the Sun's luminosity. [14] It has an estimated spectral type of K6. [9]

Nomenclature

λ Ophiuchi is the system's Bayer designation. The designations of the three components as Lambda Ophiuchi A, B and C derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU). [15]

It bore the traditional name Marfik (or Marsik), from the Arabic مرفق marfiq "elbow". In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) [16] to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems. [17] It approved the name Marfik for the component Lambda Ophiuchi A on 12 September 2016 and it is now so included in the List of IAU-approved Star Names. [12]

References

  1. ^ a b c d e f Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv: 0708.1752. Bibcode: 2007A&A...474..653V. doi: 10.1051/0004-6361:20078357. S2CID  18759600.
  2. ^ a b c d e f Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv: 1108.4971. Bibcode: 2012AstL...38..331A. doi: 10.1134/S1063773712050015. S2CID  119257644.
  3. ^ a b c d e Eggleton, P. P.; Tokovinin, A. A. (2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869. arXiv: 0806.2878. Bibcode: 2008MNRAS.389..869E. doi: 10.1111/j.1365-2966.2008.13596.x. S2CID  14878976.
  4. ^ a b c Edwards, T. W. (1976). "MK classification for visual binary components". The Astronomical Journal. 81: 245. Bibcode: 1976AJ.....81..245E. doi: 10.1086/111879.
  5. ^ Johnson, H. L.; et al. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory. 4 (99): 99. Bibcode: 1966CoLPL...4...99J.
  6. ^ Samus, N. N.; et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1. 61 (1): 80–88. Bibcode: 2017ARep...61...80S. doi: 10.1134/S1063772917010085. S2CID  125853869.
  7. ^ a b Heintz, W. D.; Strom, C. (1993). "The visual binary Lambda Ophiuchi". Astronomical Society of the Pacific. 105 (685): 293. Bibcode: 1993PASP..105..293H. doi: 10.1086/133145. S2CID  121998591.
  8. ^ a b c d Zorec, J.; et al. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics. 537: A120. arXiv: 1201.2052. Bibcode: 2012A&A...537A.120Z. doi: 10.1051/0004-6361/201117691. S2CID  55586789.
  9. ^ a b c d A. Tokovinin. "HR 6149". Multiple Star Catalogue.
  10. ^ a b "lam Oph". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-20.
  11. ^ Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN  978-1-931559-44-7.
  12. ^ a b "Naming Stars". IAU.org. Retrieved 16 December 2017.
  13. ^ 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. S2CID  14376211.
  14. ^ a b Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv: 1804.09365. Bibcode: 2018A&A...616A...1G. doi: 10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  15. ^ Hessman, F. V.; et al. (2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv: 1012.0707 [ astro-ph.SR].
  16. ^ IAU Working Group on Star Names (WGSN), International Astronomical Union, retrieved 22 May 2016.
  17. ^ "WG Triennial Report (2015–2018) – Star Names" (PDF). p. 5. Retrieved 2018-07-14.

External links

Retrieved from " https://en.wikipedia.org/?title=Lambda_Ophiuchi&oldid=1170090547"

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