Astronomy:HR 6875

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Short description: Star in the constellation Corona Australis
HR 6875
Location of HR 6875 (circled in red)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Corona Australis[1]
Right ascension  18h 24m 18.23949s[2]
Declination −44° 06′ 36.9186″[2]
Apparent magnitude (V) 5.24[1]
Characteristics
Evolutionary stage main sequence[2]
Spectral type B3 V[3]
B−V color index −0.163±0.004[1]
Astrometry
Radial velocity (Rv)+0.00±7.40[1] km/s
Proper motion (μ) RA: −1.659[2] mas/yr
Dec.: −22,022[2] mas/yr
Parallax (π)5.5671 ± 0.1134[2] mas
Distance590 ± 10 ly
(180 ± 4 pc)
Absolute magnitude (MV)−0.63[1]
Details
Mass4.5[4] M☉
Radius3.9[2] R☉
Luminosity389[4] L☉
Surface gravity (log g)4.43[5] cgs
Temperature15,803[5] K
Rotation27.2 days[6]
Rotational velocity (v sin i)248±12[7] km/s
Age103[8] Myr
Other designations
CD−44°12569, FK5 3461, HD 168905, HIP 90200, HR 6875, SAO 228982, WDS J18243-4407A[9]
Database references
SIMBADdata

HR 6875, previously known as Sigma Telescopii, is a single[10] star in the constellation Corona Australis. It has a blue-white hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.24.[1] This object is located at a distance of approximately 590 light years from the Sun based on parallax.[2] It is listed as a member of the Sco OB2 association.[7]

This is a hot B-type main-sequence star with a stellar classification of B3 V.[3] It is around 103[8] million years old and is spinning rapidly with a projected rotational velocity of 248 km/s or perhaps higher.[7] The star has 4.5 times the mass of the Sun[4] and about four times the Sun's radius.[2] It is radiating nearly 400 the luminosity of the Sun[4] from its photosphere at an effective temperature of 15,803 K[5]

A magnitude 10.13 visual companion is located at an angular separation of 74″ along a position angle of 162°.[11]

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.  XHIP record for this object at VizieR.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 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.
  3. ↑ 3.0 3.1 Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode: 1978mcts.book.....H. 
  4. ↑ 4.0 4.1 4.2 4.3 Quintana, Alexis L.; Wright, Nicholas J.; Martínez García, Juan (2025). "A census of OB stars within 1 KPC and the star formation and core collapse supernova rates of the Milky Way". Monthly Notices of the Royal Astronomical Society 538 (3): 1367. doi:10.1093/mnras/staf083. Bibcode: 2025MNRAS.538.1367Q. 
  5. ↑ 5.0 5.1 5.2 Cardiel, Nicolás; Zamorano, Jaime; Bará, Salvador; Sánchez De Miguel, Alejandro; Cabello, Cristina; Gallego, Jesús; García, Lucía; González, Rafael et al. (2021). "Synthetic RGB photometry of bright stars: Definition of the standard photometric system and UCM library of spectrophotometric spectra". Monthly Notices of the Royal Astronomical Society 504 (3): 3730. doi:10.1093/mnras/stab997. Bibcode: 2021MNRAS.504.3730C. 
  6. ↑ Oelkers, Ryan J.; Rodriguez, Joseph E.; Stassun, Keivan G.; Pepper, Joshua; Somers, Garrett; Kafka, Stella; Stevens, Daniel J.; Beatty, Thomas G. et al. (2018). "Variability Properties of Four Million Sources in the TESS Input Catalog Observed with the Kilodegree Extremely Little Telescope Survey". The Astronomical Journal 155 (1): 39. doi:10.3847/1538-3881/aa9bf4. Bibcode: 2018AJ....155...39O. 
  7. ↑ 7.0 7.1 7.2 Brown, A. G. A.; Verschueren, W. (1997), "High S/N Echelle spectroscopy in young stellar groups. II. Rotational velocities of early-type stars in SCO OB2", Astronomy and Astrophysics 319: 811, Bibcode: 1997A&A...319..811B. 
  8. ↑ 8.0 8.1 Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters 38 (11): 694–706, doi:10.1134/S1063773712110035, Bibcode: 2012AstL...38..694G. 
  9. ↑ "HD 168905". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+168905. 
  10. ↑ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E. 
  11. ↑ Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M, http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/wds, retrieved 2015-07-22