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. Bibcode2012AstL...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, Bibcode1978mcts.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. Bibcode2025MNRAS.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. Bibcode2021MNRAS.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. Bibcode2018AJ....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, Bibcode1997A&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, Bibcode2012AstL...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, Bibcode2008MNRAS.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, Bibcode2001AJ....122.3466M, http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/wds, retrieved 2015-07-22