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

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Sirius is the brightest star in the night sky. Its name is derived from the Greek word Σείριος (Latin script: Seirios), meaning lit. 'glowing' or 'scorching'. The star is designated αCanis Majoris, Latinized to Alpha Canis Majoris, and abbreviated αCMa or AlphaCMa. With a visual apparent magnitude of −1.46, Sirius is almost twice as bright as Canopus, the next brightest star. Sirius is a binary star consisting of a main-sequence star of spectral type A0 or A1, termed SiriusA, and a faint white dwarf companion of spectral typeDA2, termed SiriusB. The distance between the two varies between 8.2 and 31.5 astronomical units as they orbit every 50years. [25] 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. Tyson, Donald; Freake, James (1993). Three Books of Occult Philosophy. Llewellyn Worldwide. ISBN 0-87542-832-0.

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. The Egyptians believed that Sirius caused the floods and they noted that the star’s heliacal rising occurred every 365.25 days rather than 365 days. The correction in the length of the calendar year was eventually incorporated in the Julian calendar.

a b Barstow, M. A.; Bond, Howard E.; Holberg, J. B.; Burleigh, M. R.; Hubeny, I.; Koester, D. (2005). "Hubble Space Telescope spectroscopy of the Balmer lines in Sirius B". Monthly Notices of the Royal Astronomical Society. 362 (4): 1134–1142. arXiv: astro-ph/0506600. Bibcode: 2005MNRAS.362.1134B. doi: 10.1111/j.1365-2966.2005.09359.x. S2CID 4607496. Huygens, C. (1698). ΚΟΣΜΟΘΕΩΡΟΣ, sive De terris cœlestibus earumque ornatu conjecturae (in Latin). The Hague: Apud A. Moetjens, bibliopolam. p.137. Since 1894, irregularities have been tentatively observed in the orbits of SiriusA and B with an apparent periodicity of 6–6.4years. A 1995 study concluded that such a companion likely exists, with a mass of roughly 0.05solar mass—a small red dwarf or large brown dwarf, with an apparent magnitude of more than 15, and less than 3 arcseconds from Sirius A. [51] Sirius is mentioned in Surah, An-Najm ("The Star"), of the Qur'an, where it is given the name الشِّعْرَى (transliteration: aš-ši'rā or ash-shira; the leader). [129] The verse is: " وأنَّهُ هُوَ رَبُّ الشِّعْرَى", "That He is the Lord of Sirius (the Mighty Star)." (An-Najm:49) [130] Ibn Kathir said in his commentary "that it is the bright star, named Mirzam Al-Jawza' (Sirius), which a group of Arabs used to worship". [131] The alternate name Aschere, used by Johann Bayer, is derived from this. [19] Sirius midnight culmination at New Year 2022 local solar time [132]

To the Māori, the star marked the beginning of the winter season. They had the same name to describe both the star and the season: Takurua. Craig, John; Gravatt, William; Slater, Thomas; Rennie, George. "The Craig Telescope". craig-telescope.co.uk . Retrieved 3 January 2011. As a result of precession, Alpha Canis Majoris will move further south and, in the year 9,000, it will not be visible from most locations in northern and central Europe. In the year 14,000, when Vega takes over as the pole star, Sirius will be found at declination -67° and never set below the horizon for observers in South Africa and in most parts of Australia. SiriusA is about twice as massive as the Sun ( M ☉) and has an absolute visual magnitude of +1.43. It is 25times as luminous as the Sun, [13] but has a significantly lower luminosity than other bright stars such as Canopus, Betelgeuse, or Rigel. The system is between 200 and 300million years old. [13] It was originally composed of two bright bluish stars. The initially more massive of these, SiriusB, consumed its hydrogen fuel and became a red giant before shedding its outer layers and collapsing into its current state as a white dwarf around 120million years ago. [13]a b 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. See also: Winter Triangle A Neteru image of Sopdet, Egyptian goddess of Sirius and the fertility of the Nile, pictured with a star upon her head

The name Sirius (pronounced /ˈsɪriəs/) comes from the Latin Sīrius, which is derived from the Greek Σείριος (Seirios), meaning “scorcher” or “glowing.” The star’s other name, the Dog Star, has similar connotations. Compare the meaning of the Egyptian name with Sirius's completion of the Winter Triangle asterism, joining the other two brightest stars of the northern winter sky, Betelgeuse and Procyon. a b Gray, R.O.; Corbally, C.J.; Garrison, R.F.; McFadden, M.T.; Robinson, P.E. (2003). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of stars earlier than M0 within 40parsecs: The Northern Sample.I". Astronomical Journal. 126 (4): 2048–2059. arXiv: astro-ph/0308182. Bibcode: 2003AJ....126.2048G. doi: 10.1086/378365. S2CID 119417105.Stellar mass and lifetime on the main sequence. NASA's cosmos (diagram) . Retrieved 8 February 2021. Along with the bright stars Procyon in Canis Minor and Betelgeuse in Orion constellation, Sirius forms the Winter Triangle, a familiar asterism in the night sky, and easy to spot in winter evenings in the northern hemisphere. The only objects in the sky brighter than Sirius are the Moon, Venus, Jupiter, and occasionally Mercury and Mars. Olano, C. A. (2001). "The Origin of the Local System of Gas and Stars". The Astronomical Journal. 121 (1): 295–308. Bibcode: 2001AJ....121..295O. doi: 10.1086/318011. S2CID 120137433.