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Sirius A / B
Canis Major constellation map.svg
Cercle rouge 100%.svg
The poseetion o Sirius (circled).
Observation data
Epoch J2000.0 (ICRS)      Equinox J2000.0 (ICRS)
Constellation Canis Major
Pronunciation /ˈsɪriəs/[1]
Richt ascension 06h 45m 08.9173s[2][note 1]
Declination −16° 42′ 58.017″[2][note 1]
Apparent magnitude (V) −1.47 (A)[2] / 8.30 (B)[3]
Spectral type A1V (A)[2] / DA2 (B)[3]
U−B colour index −0.05 (A)[4] / −1.04 (B)[3]
B−V colour index 0.01 (A)[2] / −0.03 (B)[3]
Radial velocity (Rv)−7.6[2] km/s
Proper motion (μ) RA: −546.05[2][note 1] mas/yr
Dec.: −1223.14[2][note 1] mas/yr
Parallax (π)379.21 ± 1.58[2][5] mas
Distance8.60 ± 0.04 ly
(2.64 ± 0.01 pc)
Absolute magnitude (MV)1.42 (A)[note 2] / 11.18 (B)[3]
Companionα CMa B
Period (P)50.090 ± 0.055 yr
Semi-major axis (a)7.50 ± 0.04″
Eccentricity (e)0.5923 ± 0.0019
Inclination (i)136.53 ± 0.43°
Longitude o the node (Ω)44.57 ± 0.44°
Periastron epoch (T)1894.130 ± 0.015
Argument o periastron (ω)
147.27 ± 0.54°
α CMa A
Mass2.02[7] M
Radius1.711[7] R
Luminosity25.4[7] L
Surface gravity (log g)4.33[8] cgs
Temperatur9,940[8] K
Metallicity [Fe/H]0.50[9] dex
Rotation16 km/s[10]
Age2–3 × 108[7] years
α CMa B
Mass0.978[7] M
Radius0.0084 ± 3%[11] R
Luminosity0.026[note 3] L
Surface gravity (log g)8.57[11] cgs
Temperatur25,200[7] K
Ither designations
Seestem: Dug Starn, Aschere, Canicula, Al Shira, Sothis,[12] Alhabor,[13] Mrgavyadha, Lubdhaka,[14] Tenrōsei,[15] α Canis Majoris (α CMa), 9 Canis Majoris (9 CMa), HD 48915, HR 2491, BD −16°1591, GCTP 1577.00 A/B, GJ 244 A/B, LHS 219, ADS 5423, LTT 2638, HIP 32349.
B: EGGR 49, WD 0642-166.[2][16][17]

Sirius (/ˈsɪriəs/) is the brichtest starn (in fact, a starn seestem) in the Yird's nicht sky.

Notes[eedit | eedit soorce]

  1. 1.0 1.1 1.2 1.3 Astrometric data, mirrored bi SIMBAD frae the Hipparcos catalogue, pertains tae the center o mass o the Sirius seestem. See § 2.3.4, Volume 1, The Hipparcos and Tycho Catalogues, European Space Agency, 1997, and the entry for Sirius in the Hipparcos catalogue (CDS ID I/239.)
  2. For apparent magnitude m an parallax π, the absolute magnitude Mv o Sirius A is gien bi:
    See: Tayler, Roger John (1994). The Stars: Their Structure and Evolution. Cambridge University Press. p. 16. ISBN 0-521-45885-4.
  3. Bolometric luminosity o Sirius B calculatit frae L=4πR2σTeff4. (This simplifies tae Ls=(Rs)^2*(Ts)^4, whaur Ls, Rs an Ts are Luminosity, Radius an Temperatur aw relative tae solar values) See: Tayler, Roger John (1994). The Stars: Their Structure and Evolution. Cambridge University Press. p. 16. ISBN 0-521-45885-4.

References[eedit | eedit soorce]

  1. "Sirius". Unabridged (v 1.1). Random House, Inc. Retrieved 6 April 2008.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 "Sirius A". SIMBAD Astronomical Database. Centre de Données astronomiques de Strasbourg. Retrieved 20 October 2007.
  3. 3.0 3.1 3.2 3.3 3.4 McCook, G. P.; Sion, E. M. "Entry for WD 0642-166". A Catalogue of Spectroscopically Identified White Dwarfs (August 2006 version). CDS.CS1 maint: multiple names: authors leet (link) ID III/235A.)
  4. Hoffleit, D.; Warren, Jr., W. H. (1991). "Entry for HR 2491". Bright Star Catalogue, 5th Revised Ed. (Preliminary Version). CDS. Italic or bold markup not allowed in: |work= (help)CS1 maint: multiple names: authors leet (link) ID V/50.
  5. van Leeuwen, F. (November 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
  6. van den Bos, W. H. (1960). "The Orbit of Sirius". Journal des Observateurs. 43: 145–151. Bibcode:1960JO.....43..145V.CS1 maint: ref=harv (link)
  7. 7.0 7.1 7.2 7.3 7.4 7.5 Liebert, J.; Young, P. A.; Arnett, D.; Holberg, J. B.; Williams, K. A. (2005). "The Age and Progenitor Mass of Sirius B". The Astrophysical Journal. 630 (1): L69–L72. arXiv:astro-ph/0507523. Bibcode:2005ApJ...630L..69L. doi:10.1086/462419.CS1 maint: ref=harv (link)
  8. 8.0 8.1 Adelman, Saul J. (July 8–13, 2004). "The Physical Properties of normal A stars". Proceedings of the International Astronomical Union. Poprad, Slovakia: Cambridge University Press. pp. 1–11. Bibcode:2004IAUS..224....1A.
  9. Qiu, H. M.; Zhao, G.; Chen, Y. Q.; Li, Z. W. (2001). "The Abundance Patterns of Sirius and Vega". The Astrophysical Journal. 548 (2): 953–965. Bibcode:2001ApJ...548..953Q. doi:10.1086/319000.CS1 maint: ref=harv (link)
  10. Royer, F.; Gerbaldi, M.; Faraggiana, R.; Gómez, A. E. (2002). "Rotational velocities of A-type stars. I. Measurement of v sin i in the southern hemisphere". Astronomy and Astrophysics. 381 (1): 105–121. arXiv:astro-ph/0110490. Bibcode:2002A&A...381..105R. doi:10.1051/0004-6361:20011422.CS1 maint: ref=harv (link)
  11. 11.0 11.1 Holberg, J. B.; Barstow, M. A.; Bruhweiler, F. C.; Cruise, A. M.; Penny, A. J. (1998). "Sirius B: A New, More Accurate View". The Astrophysical Journal. 497 (2): 935–942. Bibcode:1998ApJ...497..935H. doi:10.1086/305489.CS1 maint: ref=harv (link)
  12. Hinckley, Richard Allen (1899). Star-names and Their Meanings. New York: G. E. Stechert. pp. 117–25.
  13. doi:10.1111/j.1749-6632.1987.tb37197.x
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  14. Singh, Nagendra Kumar (2002). Encyclopaedia of Hinduism, A Continuing Series. Anmol Publications PVT. LTD. p. 794. ISBN 81-7488-168-9.
  15. Spahn, Mark; Hadamitzky, Wolfgang; Fujie-Winter, Kimiko (1996). The Kanji dictionary. Tuttle language library. Tuttle Publishing. p. 724. ISBN 0-8048-2058-9.CS1 maint: multiple names: authors leet (link)
  16. "Sirius B". SIMBAD Astronomical Database. Centre de Données astronomiques de Strasbourg. Retrieved 23 October 2007.
  17. van Altena, W. F.; Lee, J. T.; Hoffleit, E. D. (1995). The general catalogue of trigonometric parallaxes (4th ed.). Yale University Observatory. (CDS) ID I/238A.

Coordinates: Sky map 06h 45m 08.9173s, −16° 42′ 58.017″