The Dog Stars: The hope-filled story of a world changed by global catastrophe

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In his 1698 book, Cosmotheoros, Christiaan Huygens estimated the distance to Sirius at 27,664times the distance from the Earth to the Sun (about 0.437light-year, translating to a parallax of roughly 7.5arcseconds). [42] There were several unsuccessful attempts to measure the parallax of Sirius: by Jacques Cassini (6seconds); by some astronomers (including Nevil Maskelyne) [43] using Lacaille's observations made at the Cape of Good Hope (4seconds); by Piazzi (the same amount); using Lacaille's observations made at Paris, more numerous and certain than those made at the Cape (no sensible parallax); by Bessel (no sensible parallax). [44]

Schaaf, Fred (2008). The Brightest Stars. Hoboken, New Jersey: John Wiley & Sons. p.94. ISBN 978-0-471-70410-2. a b c d e f g h i j k l Liebert, James; Young, P. A.; Arnett, David; Holberg, J. B.; Williams, Kurtis 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. S2CID 8792889. a b c d Kervella, P.; Thevenin, F.; Morel, P.; Borde, P.; Di Folco, E. (2003). "The interferometric diameter and internal structure of Sirius A". Astronomy and Astrophysics. 407 (2): 681–688. arXiv: astro-ph/0306604. Bibcode: 2003A&A...408..681K. doi: 10.1051/0004-6361:20030994. S2CID 16678626. Baker, Douglas (1977). The Seven Rays: Key to the Mysteries. Wellingborough, Herts.: Aquarian Press. ISBN 0-87728-377-X. Henderson, T. (1839). "On the parallax of Sirius". Monthly Notices of the Royal Astronomical Society. 5 (2): 5–7. Bibcode: 1839MNRAS...5....5H. doi: 10.1093/mnras/5.2.5.Alpha Canis Majoris appears as a single star to the unaided eye, but it is really a binary star system, composed of a white main sequence star belonging to the spectral class A1 V, known as Sirius A or Alpha Canis Majoris A, and a dim white dwarf with the stellar classification DA2, designated Sirius B or Alpha Canis Majoris B.

Appletons' annual cyclopaedia and register of important events of the year: 1862. New York: D. Appleton & Company. 1863. p.176. In ancient Egypt, Sirius was known as Sopdet (Greek: Σῶθις, or Sothis), the goddess who was part of the triad with her husband Osiris and son Horus. The hieroglyph for Sothis has a star and a triangle.Sweeney, M.A. (1976). "Cooling times, luminosity functions and progenitor masses of degenerate dwarfs". Astronomy and Astrophysics. 49: 375–385. Bibcode: 1976A&A....49..375S. Imamura, James N. (2 October 1995). "Cooling of White Dwarfs". University of Oregon. Archived from the original on 15 December 2006 . Retrieved 3 January 2007. Several occult researchers believe that the Great Pyramid of Giza was constructed in perfect alignment with stars, particularly with Sirius and the three stars of the Orion’s Belt. Recent findings related to the pyramid’s mysterious air shafts have strengthened the theory of Sirius’ importance to Egyptians.

Ceragioli, R. C. (1995). "The Debate Concerning 'Red' Sirius". Journal for the History of Astronomy. 26 (3): 187–226. Bibcode: 1995JHA....26..187C. doi: 10.1177/002182869502600301. S2CID 117111146. It is, however, significantly less luminous than Canopus, Rigel, and many other bright stars that lie at greater distances.a b c Whittet, D. C. B. (1999). "A physical interpretation of the 'red Sirius' anomaly". Monthly Notices of the Royal Astronomical Society. 310 (2): 355–359. Bibcode: 1999MNRAS.310..355W. doi: 10.1046/j.1365-8711.1999.02975.x. Sirius B has a mass almost equal to the Sun, 0.98 solar masses, which makes it one of the more massive white dwarfs known. However, the star’s mass is concentrated into a volume comparable to that of the Earth. Sirius B has a almost the diameter of our planet, 12,000 kilometres, or 7,500 miles. The star’s diameter was measured in 2005 using the Hubble Space Telescope. Sirius A is classified as an Am star because studies of the star’s spectrum have revealed deep metallic absorption lines, suggesting a significant presence of elements heavier than helium, like iron. The star has 316% of the proportion of iron found in the atmosphere of our Sun.

Maskelyne, N. (1759). "LXXVIII. A proposal for discovering the annual parallax of Sirius". Philosophical Transactions of the Royal Society. 51: 889–895. Bibcode: 1759RSPT...51..889M. doi: 10.1098/rstl.1759.0080. Hanbury Brown, R.; Twiss, R. Q. (1958). "Interferometry of the Intensity Fluctuations in Light. IV. A Test of an Intensity Interferometer on Sirius A". Proceedings of the Royal Society of London. 248 (1253): 222–237. Bibcode: 1958RSPSA.248..222B. doi: 10.1098/rspa.1958.0240. S2CID 124546373. In 1868, Sirius became the first star to have its velocity measured, the beginning of the study of celestial radial velocities. Sir William Huggins examined the spectrum of the star and observed a red shift. He concluded that Sirius was receding from the Solar System at about 40km/s. [39] [40] Compared to the modern value of −5.5km/s, this was an overestimate and had the wrong sign; the minus sign (−) means that it is approaching the Sun. [41] Distance [ edit ] The binary companion was discovered by the German astronomer Friedrich Bessel, who deduced that the star had an unseen companion from the changes in the proper motion of the main component.See also: Sirius in fiction The position of Sirius on a radar map among all stellar objects or stellar systems within 9 light years (ly) from the map's center, the Sun (Sol). The diamond-shapes are their positions entered according to right ascension in hours angle (indicated at the edge of the map's reference disc), and according to their declination. The second mark shows each's distance from Sol, with the concentric circles indicating the distance in steps of one ly. Malkov, O. Yu. (December 2007). "Mass-luminosity relation of intermediate-mass stars". Monthly Notices of the Royal Astronomical Society. 382 (3): 1073–1086. Bibcode: 2007MNRAS.382.1073M. doi: 10.1111/j.1365-2966.2007.12086.x. The orbital motion of the Sirius binary system brings the two stars to a minimum angular separation of 3 arcseconds and a maximum of 11arcseconds. At the closest approach, it is an observational challenge to distinguish the white dwarf from its more luminous companion, requiring a telescope with at least 300mm (12in) aperture and excellent seeing conditions. After a periastron occurred in 1994, [c]