Astronomy:V1054 Ophiuchi

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Short description: Star system in the constellation Ophiuchus

Coordinates: Sky map 16h 55m 32.0s, −08° 21′ 30″

V1054 Ophiuchi
250px
An ultraviolet band light curve for a flare on V1054 Ophiuchi, plotted from data published by Dal and Evren (2010)[1]
Observation data
{{#ifeq:J2000|J2000.0 (ICRS)|Epoch J2000.0      Equinox J2000.0 (ICRS)| Epoch J2000      [[Astronomy:Equinox (celestial coordinates)|Equinox J2000}}
Constellation Ophiuchus[2]
AB
Right ascension  16h 55m 28.75757s[3]
Declination −08° 20′ 10.7878″[3]
Apparent magnitude (V) 9.74/10.34/10.84[4]
Gliese 643
Right ascension  16h 55m 25.22225s[5]
Declination −08° 19′ 21.2970″[5]
Apparent magnitude (V) 11.74[4]
C (VB 8)
Right ascension  16h 55m 35.25574s[6]
Declination −08° 23′ 40.7531″[6]
Apparent magnitude (V) 16.80[4]
Characteristics
AB
Spectral type M3 V[7] / M4 Ve[note 1]
Gliese 643
Spectral type M3.5 V[7]
C (VB 8)
Spectral type M7.0 V[4]
Astrometry
AB
Radial velocity (Rv)14.89±0.05[8] km/s
Proper motion (μ) RA: −817.84±6.68[3] mas/yr
Dec.: −873.53±3.53[3] mas/yr
Parallax (π)161.41 ± 5.64[3] mas
Distance20.2 ± 0.7 ly
(6.2 ± 0.2 pc)
Absolute magnitude (MV)10.23[2]
Gliese 643
Radial velocity (Rv)15.20±0.15[5] km/s
Proper motion (μ) RA: −817.580(52)[5] mas/yr
Dec.: −898.595(40)[5] mas/yr
Parallax (π)153.8754 ± 0.0474[5] mas
Distance21.196 ± 0.007 ly
(6.499 ± 0.002 pc)
Absolute magnitude (MV)12.60[2]
VB 8
Proper motion (μ) RA: −813.038(63) mas/yr
Dec.: −870.609(44) mas/yr
Parallax (π)153.9659 ± 0.0570[6] mas
Distance21.184 ± 0.008 ly
(6.495 ± 0.002 pc)
Absolute magnitude (MV)17.75[4]
Orbit[9]
PrimaryV1054 Oph A
CompanionV1054 Oph B
Period (P)1.71741±0.00005 yr
Semi-major axis (a)0.22949±0.00046″
Eccentricity (e)0.04225±0.00092
Inclination (i)161.30±0.49°
Longitude of the node (Ω)164.7±1.6°
Periastron epoch (T)1991.6311±0.0063
Argument of periastron (ω)
(secondary)
128.7±3.3°
Orbit[7]
PrimaryV1054 Oph Ba
CompanionV1054 Oph Bb
Period (P)2.965509±0.000006 d
Semi-major axis (a)0.00687[note 2]"
(0.04432 astronomical unit|AU[note 3])
Eccentricity (e)0.0209±0.0008
Inclination (i)164.18±0.08°
Periastron epoch (T)MJD 50919.48±0.03
Argument of periastron (ω)
(secondary)
150.0±3.0°
Details
A
Mass0.4155±0.0057[7] M☉
Radius0.533±0.021[10] R☉
Luminosity0.02[2] L☉
Surface gravity (log g)4.7083 ± 0.0145[10] cgs
Temperature3,537±67[11] K
Ba
Mass0.3466±0.0047[7] M☉
Bb
Mass0.3143±0.0040[7] M☉
Gliese 643
Mass0.207±0.010[12] M☉
Radius0.282+0.002
−0.005
[5] R☉
Luminosity0.005303+0.000004−0.000005[5] L☉
Surface gravity (log g)4.488 ± 0.006[5] cgs
Temperature3,028+4
−5
[5] K
Metallicity [Fe/H]-0.794 ± 0.008[5] dex
C (VB 8)
Mass0.0914+0.0026
−0.0025
[13] M☉
Radius0.1214+0.0060
−0.0057
[13] R☉
Luminosity0.000645+0.000004−0.000005[13] L☉
Temperature2,640+65
−64
[13] K
Rotation11.19±0.02[14] days
Other designations
CCDM J16555-0820
AB: V1054 Oph, BD−08°4352, GJ 644, HD 152751, HIP 82817, SAO 141439, LHS 428, Wolf 630[15]
GJ 643: GJ 643, HIP 82809, LHS 427, Wolf 629[16]
C: GJ 644 C, LHS 429, VB 8[17]
Database references
SIMBADABab
GJ 643
C (vB 8)

V1054 Ophiuchi, together with the star Gliese 643, is a nearby quintuple star system, located in the constellation Ophiuchus at a distance of 21.2 light-years (6.5 parsecs). It consists of five stars, all of which are red dwarfs. The alternative designation of Wolf 630 forms the namesake of a moving group of stars that share a similar motion through space.[18]

Overview

A
P = 1.72 yr
Ba
P = 2.97 d
Bb
72″ separation
GJ 643
220″ separation
C (VB 8)

Hierarchy of orbits in the system[4]

V1054 Ophiuchi/Gliese 643 is the nearest quintuple star system;[4] the next nearest star systems with at least five stars are Xi Ursae Majoris (quintuple, including a brown dwarf)[19] at 28.5 light-years, Castor[4] (sextuple) at 49.2 light-years, and GJ 2069 (quintuple)[7] at 54.3 light-years. V1054 Ophiuchi and Xi Ursae Majoris are the only two quintuple star systems within 10 parsecs.[19]

The system consists of three widely separated parts:

  • close triple subsystem V1054 Ophiuchi A-Bab (including very close binary subsystem V1054 Ophiuchi Bab)
  • Gliese 643
  • V1054 Ophiuchi C (vB 8)

The brightest and most massive of these five stars is V1054 Ophiuchi A. The close binary subsystem V1054 Ophiuchi B is more massive than V1054 Ophiuchi A, however, its total visual magnitude is 0.1 mag fainter than V1054 Ophiuchi A's visual magnitude.[4]

The total apparent magnitude of the V1054 Ophiuchi A-Bab triple subsystem is 9.02.[4][20]

Despite V1054 Ophiuchi/Gliese 643 consisting of low-mass stars, the system's total mass, due to the large number of components, exceeds the Solar mass,[4] about 1.35 M☉.

Distance

Currently, the most accurate distance estimate of V1054 Ophiuchi/Gliese 643 is a trigonometric parallax of Gliese 643 from Gaia DR3:[5] 153.8754±0.0474 mas, corresponding to a distance of 6.499±0.002 pc, or 21.196±0.007 ly.

Past V1054 Ophiuchi/Gliese 643 distance estimates

V1054 Ophiuchi A-Bab:

Source Paper Parallax, mas Distance, pc Distance, ly Ref.
Woolley Woolley et al. 1970 156 ± 4 6.41 ± 0.17 20.9 ± 0.6 [21]
GJ, 3rd version Gliese & Jahreiß 1991 153.9 ± 2.6 6.50 ± 0.11 21.19 ± 0.36 [22]
YPC, 4th edition van Altena et al. 1995 154.8 ± 0.6 6.460 ± 0.025 21.07 ± 0.08 [23]
Hipparcos Perryman 1997 174.23 ± 3.90 5.74 ± 0.13 18.7 ± 0.4 [20]
Soederhjelm Soederhjelm 1999 155.63 ± 1.81 6.43 ± 0.08 20.96 ± 0.25 [24]
Hipparcos2 van Leeuwen 2007 161.41 ± 5.64 6.20 ± 0.22 20.21 ± 0.73 [3]

Gliese 643:

Source Paper Parallax, mas Distance, pc Distance, ly Ref.
Woolley Woolley et al. 1970 169 ± 5 5.92 ± 0.18 19.3 ± 0.6 [21]
GJ, 3rd version Gliese & Jahreiß 1991 171.9 ± 7.3 5.82 ± 0.26 19.0 ± 0.8 [22]
YPC, 4th edition van Altena et al. 1995 169.8 ± 6.6 5.89 ± 0.24 19.2 ± 0.8 [23]
Hipparcos Perryman 1997 153.96 ± 4.04 6.50 ± 0.18 21.2 ± 0.6 [20]
Hipparcos2 van Leeuwen 2007 148.92 ± 4.00 6.72 ± 0.19 21.9 ± 0.6 [3]

V1054 Ophiuchi C (vB 8):

Source Paper Parallax, mas Distance, pc Distance, ly Ref.
CTIOPI 1.5 m TSN 14 (Costa et al. 2005) 155.43 ± 1.33 6.43 ± 0.06 20.98 ± 0.18 [25]

Weighted mean distance

A weighted mean parallax[26] was calculated by RECONS in 2012, considering YPC (V1054 Ophiuchi A-Bab and Gliese 643), Hipparcos (Soederhjelm — V1054 Ophiuchi A-Bab and van Leeuwen — Gliese 643) and CTIOPI (V1054 Ophiuchi C) data. The value is 154.96±0.52 mas,[27] corresponding to a distance of 6.453±0.022 pc, or 21.05±0.07 ly. This predates Gaia astrometry of the system.

System

V1054 Ophiuchi A-Bab (inner triple subsystem)

V1054 Ophiuchi A-Bab is a close spectroscopic triple subsystem, consisting of the brighter component V1054 Ophiuchi A and the more massive binary subsystem V1054 Ophiuchi Bab, orbiting each other with a period of 627 days,[7][4] or 1.72 years.[4] V1054 Ophiuchi Bab components are orbiting each other with a period of 2.9655 days.[7][4] Both outer and inner orbits are nearly circular and, probably, coplanar[7][4] (in keeping with a general tendency of close triple systems).[7]

V1054 Ophiuchi A-Bab pair is also visually resolved (for nearly 50 years it was the shortest-period resolved by visual means binary, since its binarity was discovered by G. P. Kuiper in 1934),[4] whereas V1054 Ophiuchi Ba-Bb pair is still unresolved).[7][4][note 4]

Gliese 643

The projected separation of Gliese 643 from V1054 Ophiuchi A-Bab is 72 arcsec,[7] corresponding at 21.05 light-years to 465 AU.

V1054 Ophiuchi C (vB 8)

vB 8 is the smallest, faintest, and most separated component of the V1054 Ophiuchi system. The projected separation of the red dwarf from the primary triple system is about 220 arcsec,[7][4] corresponding at 21.05 light-years to 1420 a.u. Since it is only three times larger than the projected separation between Gliese 643 and V1054 Ophiuchi A-Bab, and such a small ratio should render the triple system dynamically unstable, it was suggested[4] that the real separation of V1054 Ophiuchi C from V1054 Ophiuchi A-Bab is much larger, at least by a factor of two,[4] i. e. at least 2840 a.u.

In 1984, the apparent detection of an infrared source near vB 8 suggested it had a low mass companion. The low mass of this candidate led to speculation that it may be a brown dwarf; the first such to be detected. This discovery was later found to be spurious, but it produced much interest in this class of astronomical object.[28]

Notes

  1. ↑ Referred to entire V1054 Ophiuchi Bab subsystem.
  2. ↑ From masses, period and parallax.
  3. ↑ From masses and period. According to Mazeh et al. 2001, of order of 0.05 a. u.
  4. ↑ At least it was not resolved by 2001.

References

  1. ↑ Dal, H. A.; Evren, S. (August 2010). "A New Method for Classifying Flares of UV Ceti Type Stars: Differences Between Slow and Fast Flares". The Astronomical Journal 140 (2): 483–489. doi:10.1088/0004-6256/140/2/483. Bibcode: 2010AJ....140..483D. 
  2. ↑ 2.0 2.1 2.2 2.3 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A. 
  3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Vizier, Hipparcos, the New Reduction (van Leeuwen 2007)
  4. ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 4.12 4.13 4.14 4.15 4.16 4.17 4.18 4.19 Mazeh, Tsevi; Latham, David W.; Goldberg, Elad; Torres, Guillermo; Stefanik, Robert P.; Henry, Todd J.; Zucker, Shay; Gnat, Orly et al. (2001). "Studies of multiple stellar systems - IV. The triple-lined spectroscopic system V1054 Ophiuchi". Monthly Notices of the Royal Astronomical Society 325 (1): 343–357. doi:10.1046/j.1365-8711.2001.04419.x. Bibcode: 2001MNRAS.325..343M. 
  5. ↑ 5.00 5.01 5.02 5.03 5.04 5.05 5.06 5.07 5.08 5.09 5.10 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  6. ↑ 6.0 6.1 6.2 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  7. ↑ 7.00 7.01 7.02 7.03 7.04 7.05 7.06 7.07 7.08 7.09 7.10 7.11 7.12 7.13 Ségransan, Damien; Delfosse, Xavier; Forveille, Thierry; Beuzit, Jean-Luc; Udry, Stéphane; Perrier, Christian; Mayor, Michel (2000). "Accurate masses of very low mass stars. III. 16 new or improved masses". Astronomy and Astrophysics 364: 665–673. Bibcode: 2000A&A...364..665S. 
  8. ↑ Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; Levato, H.; Morrell, N. I.; Torres, G. et al. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics 424: 727. doi:10.1051/0004-6361:20041213. Bibcode: 2004A&A...424..727P. 
  9. ↑ Mason, Brian D.; Tokovinin, Andrei; Mendez, Rene A.; Costa, Edgardo (October 2023). "Speckle Interferometry at SOAR in 2022" (in en). The Astronomical Journal 166 (4): 139. doi:10.3847/1538-3881/acedaf. ISSN 0004-6256. Bibcode: 2023AJ....166..139M. 
  10. ↑ 10.0 10.1 Stassun, Keivan G.; Oelkers, Ryan J.; Paegert, Martin; Torres, Guillermo; Pepper, Joshua; De Lee, Nathan; Collins, Kevin; Latham, David W. et al. (2019-10-01). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. ISSN 0004-6256. Bibcode: 2019AJ....158..138S. 
  11. ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  12. ↑ González-Payo, J.; Caballero, J.; Cifuentes, C; Cortés-Contreras, M.; Rica, F. (7 May 2026). "Characterisation of all known multiple stellar systems within 10 pc". Monthly Notices of the Royal Astronomical Society 549 (1). doi:10.1093/mnras/stag838. Bibcode: 2026MNRAS.549ag838G. 
  13. ↑ 13.0 13.1 13.2 13.3 Pineda, J. Sebastian; Youngblood, Allison; France, Kevin (September 2021). "The M-dwarf Ultraviolet Spectroscopic Sample. I. Determining Stellar Parameters for Field Stars". The Astrophysical Journal 918 (1): 23. doi:10.3847/1538-4357/ac0aea. 40. Bibcode: 2021ApJ...918...40P. 
  14. ↑ Kemmer, J.; Lafarga, M.; Fuhrmeister, B.; Shan, Y.; Schöfer, P.; Jeffers, S. V.; Caballero, J. A.; Quirrenbach, A. et al. (2025-04-11). "The CARMENES search for exoplanets around M dwarfs. Cluster analysis of signals from spectral activity indicators to search for shared periods". Astronomy and Astrophysics 697. doi:10.1051/0004-6361/202347056. Bibcode: 2025A&A...697A.225K. 
  15. ↑ "HD 152751". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+152751. 
  16. ↑ "GJ 643". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=GJ+643. 
  17. ↑ "VB 8". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=VB+8. 
  18. ↑ Bubar, Eric J.; King, Jeremy R. (August 2010). "Spectroscopic Abundances and Membership in the Wolf 630 Moving Group". The Astronomical Journal 140 (2): 293–318. doi:10.1088/0004-6256/140/2/293. Bibcode: 2010AJ....140..293B. 
  19. ↑ 19.0 19.1 Reylé, Céline; Jardine, Kevin; Fouqué, Pascal; Caballero, Jose A.; Smart, Richard L.; Sozzetti, Alessandro (30 April 2021). "The 10 parsec sample in the Gaia era". Astronomy & Astrophysics 650: A201. doi:10.1051/0004-6361/202140985. Bibcode: 2021A&A...650A.201R.  Data available at https://gruze.org/10pc/
  20. ↑ 20.0 20.1 20.2 Vizier, The Hipparcos and Tycho Catalogues (ESA 1997)
  21. ↑ 21.0 21.1 Vizier, Stars within 25 pc of the Sun (Woolley+ 1970)
  22. ↑ 22.0 22.1 Vizier, Nearby Stars, Preliminary 3rd Version (Gliese+ 1991)
  23. ↑ 23.0 23.1 VizieR, Yale Trigonometric Parallaxes, Fourth Edition (van Altena+ 1995)
  24. ↑ Vizier, Visual binary orbits and masses (Soederhjelm 1999)
  25. ↑ Costa, Edgardo (2005). "The Solar Neighborhood. XIV. Parallaxes from the Cerro Tololo Inter-American Observatory Parallax Investigation-First Results from the 1.5 m Telescope Program". The Astronomical Journal 130 (1): 337–349. doi:10.1086/430473. Bibcode: 2005AJ....130..337C. 
  26. ↑ DENSE Project. 25 pc White Dwarf Sample (see formulae below)
  27. ↑ THE ONE HUNDRED NEAREST STAR SYSTEMS brought to you by RECONS (Research Consortium On Nearby Stars)
  28. ↑ Reid, Neill I.; Hawley, Suzanne L. (27 November 2013). New Light on Dark Stars: Red Dwarfs, Low-Mass Stars, Brown Dwarfs. Astronomy and Planetary Sciences. Springer Science & Business Media, 2013. p. 344. ISBN 978-1447136637. https://books.google.com/books?id=04_aBwAAQBAJ&pg=PA344.