Eta Canis Majoris (η Canis Majoris, abbreviated Eta CMa, η CMa), also named Aludra/əˈluːdrə,əˈljuːdrə/,[10] is a
star in the
constellation of
Canis Major. Since 1943, the
spectrum of this star has served as one of the stable anchor points by which other stars are classified.[11]
The traditional name Aludra originates from the
Arabic: العذراءal-adhraa, 'the virgin'. This star, along with
Epsilon Canis Majoris (Adhara),
Delta Canis Majoris (Wezen) and
Omicron2 Canis Majoris (Thanih al Adzari), were Al 'Adhārā (العذاري), 'the Virgins'.[12] In 2016, the
International Astronomical Union organized a
Working Group on Star Names (WGSN)[13] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[14] included a table of the first two batches of names approved by the WGSN; which included Aludra for this star.
Eta CMa shines brightly in the skies in spite of a large distance from
Earth due to being
intrinsically many times brighter than the
Sun. It has a luminosity over 100,000 times and a radius around 54 times that of the Sun. It has only been around a fraction of the time the Sun has, less than 10 million years, yet is already in the last stages of its life. It is still expanding and may become a red supergiant, or perhaps has already passed that phase, but in either case it will become a
supernova within the next few million years.[citation needed]
Eta CMa is classified as an
Alpha Cygni-typevariable star and its brightness varies from magnitude +2.38 to +2.48 over a period of 4.7 days.[4][19]
^
abKazarovets, E. V.; Samus, N. N.; Durlevich, O. V.; Frolov, M. S.; Antipin, S. V.; Kireeva, N. N.; Pastukhova, E. N. (1999). "The 74th Special Name-list of Variable Stars". Information Bulletin on Variable Stars. 4659: 1.
Bibcode:
1999IBVS.4659....1K.
^Wielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veröff. Astron. Rechen-Inst. Heidelb, 35 (35), Astronomisches Rechen-Institut Heidelberg: 1,
Bibcode:
1999VeARI..35....1W
^"Light Curve". Hipparcos ESA. ESA. Retrieved 12 August 2022.
^Morgan, W. W.; Abt, Helmut A.; Tapscott, J. W. (1978). Revised MK Spectral Atlas for stars earlier than the sun. Yerkes Observatory, University of Chicago.
Bibcode:
1978rmsa.book.....M.{{
cite book}}: CS1 maint: location missing publisher (
link)