R Canis Majoris

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R Canis Majoris
Canis Major constellation map.svg
Red circle.svg
Location of R CMa (circled)
Observation data
Epoch J2000.0        Equinox
Constellation Canis Major
Right ascension 07h 19m 28.18202s [1]
Declination 16° 23 42.8773 [1]
Apparent magnitude  (V)5.70 - 6.34 [2]
Characteristics
Spectral type F0V + G8IV [3]
U−B color index +0.01 [3]
B−V color index +0.34 [3]
Variable type Algol
Astrometry
Radial velocity (Rv)-39.0 [4]  km/s
Proper motion (μ)RA: 165.37 [1]   mas/yr
Dec.: 136.18 [1]   mas/yr
Parallax (π)23.38 ± 0.54  mas [1]
Distance 44 [3]   pc
Absolute magnitude  (MV)+2.57 [5]
Details [3]
Mass 1.67 + 0.22 + 0.8  M
Radius 1.78 + 1.22 + 0.83  R
Luminosity 8.2 + 0.49 + 0.4  L
Surface gravity (log g)4.16 + 3.60 + 4.50  cgs
Temperature 6,964 [5]   K
Rotational velocity (v sin i)78.3±3.9 [5]  km/s
Other designations
R  Canis Majoris, BD 16° 1898, HR  2788, HD  57167, HIP  35487, SAO  152724, GC  9758
Database references
SIMBAD data

R Canis Majoris is an eclipsing interacting binary star system in the constellation Canis Major. It varies from magnitude 5.7 to 6.34. [6] The system is unusual in the low ratio between the main two components and shortness of the orbital period. [3]

Contents

Eclipse timings

A visual band light curve for R Canis Majoris, adapted from Shobbrook (2005) RCMaLightCurve.png
A visual band light curve for R Canis Majoris, adapted from Shobbrook (2005)

Eclipse timings for R Canis Majoris have been being measured since 1887, and whilst at present the time period appears constant at 1.1359 days, periodic quasi-sinusoidal variations of the eclipse arrival times have been taking place with a periodicity of around 93 years. This has led to the suggestion that there exists a third non-eclipsing body in the system whose gravitational pull is responsible for these variations. [8]

Interacting binary star

R Canis Majoris is thought to be an interacting binary star. The secondary star has exceeded its Roche lobe and accreted mass to the primary star. This has resulted in the early evolution of the secondary star into the subgiant branch, and increased helium rich material in the primary, causing it to burn brighter and have a higher effective temperature than would usually be expected for a star of its mass. [9]

Reanalysis of the system using high-resolution spectroscopy yields its two main components to have masses 1.67 ± 0.08, and 0.22 ± 0.07 times that of the Sun respectively and radii 1.78 ± 0.03 and 1.22 ± 0.07 times that of the Sun respectively. Their surface temperatures are 7300 and 4350 K. The third star has a mass 80% that of the Sun and a radius around 83% that of the Sun. A third star in the system is very faint, presumably an orange dwarf. [3]

Related Research Articles

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Beta Canis Majoris, also named Mirzam, is a star in the southern constellation of Canis Major, the "Great Dog", located at a distance of about 500 light-years (150 parsecs) from the Sun. In the modern constellation it lies at the position of the dog's front leg.

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Omicron<sup>1</sup> Canis Majoris Variable star in the constellation Canis Major

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<span class="mw-page-title-main">Sigma Canis Majoris</span> Variable star in the constellation Canis Major

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<span class="mw-page-title-main">UW Canis Majoris</span> Beta Lyrae variable star in the constellation Canis Major

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<span class="mw-page-title-main">Chi Draconis</span> Star in the constellation of Draco

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<span class="mw-page-title-main">Zeta Cephei</span> Star in the constellation Cepheus

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<span class="mw-page-title-main">HR 2554</span> Star in the constellation Carina

HR 2554, also known as V415 Carinae and A Carinae, is an eclipsing spectroscopic binary of the Algol type in the constellation of Carina whose apparent visual magnitude varies by 0.06 magnitude and is approximately 4.39 at maximum brightness. Its primary is a G-type bright giant star and its secondary is an A-type main-sequence star. It is approximately 553 light-years from Earth.

<span class="mw-page-title-main">EZ Canis Majoris</span> Binary star system in the constellation Canis Major

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<span class="mw-page-title-main">R Arae</span> Variable star in the constellation Ara

R Arae is an Algol-type eclipsing binary in the constellation Ara. Located approximately 298 parsecs (970 ly) distant, it normally shines at magnitude 6.17, but during eclipses can fall as low as magnitude 7.32. It has been suggested by multiple studies that mass transfer is occurring between the two stars of this system, and the period of eclipses seems to be increasing over time. The primary is a blue-white main sequence star of spectral type B5V that is 5 times as massive as the Sun, while the secondary is a yellow-white star of spectral type F1IV that is 1.5 times as massive as the Sun. Stellar material is being stripped off the secondary and accreting on the primary.

<span class="mw-page-title-main">LY Aurigae</span> Binary star in the constellation Auriga

LY Aurigae is a multiple star system in the constellation Auriga. It is an eclipsing binary variable star, dropping in brightness by 0.7 magnitudes every 4 days. The system is around a thousand light years away in the Auriga OB1 stellar association.

<span class="mw-page-title-main">1 Geminorum</span> Triple star system in the constellation Gemini

1 Geminorum is a star in the constellation Gemini. Its apparent magnitude is 4.15.

<span class="mw-page-title-main">72 Pegasi</span> Binary star system in the constellation Pegasus

72 Pegasi is a binary star system in the northern constellation of Pegasus. It is visible to the naked eye as a faint, orange-hued point of light with a combined apparent visual magnitude of 4.97. The system is located approximately 550 light years away from the Sun, based on parallax, but is drifting closer with a radial velocity of −25 km/s.

<span class="mw-page-title-main">42 Persei</span> Binary star system in the constellation Perseus

42 Persei is a binary star system in the northern constellation of Perseus. It has the Bayer designation n Persei, while 42 Persei is the Flamsteed designation. The system is visible to the naked eye as a dim, white-hued point of light with an apparent visual magnitude of 5.11. It is located around 93 parsecs (302 ly) distant from the Sun, but is drifting closer with a radial velocity of −12.4 km/s.

<span class="mw-page-title-main">RR Centauri</span> Star in the constellation Centaurus

RR Centauri is a variable star of apparent magnitude maximum +7.29. It is located in the constellation of Centaurus, approximately 320 light years distant from the solar system.

<span class="mw-page-title-main">CX Canis Majoris</span> Blue variable star in the constellation Canis Major

CX CMa is a blue variable star in the Canis Major constellation. Discovery of this variable is usually credited to German Astronomer Cuno Hoffmeister in 1931, although this remains uncertain.

<span class="mw-page-title-main">65 Ursae Majoris</span> Star system in the constellation Ursa Major

65 Ursae Majoris, abbreviated as 65 UMa, is a star system in the constellation of Ursa Major. With a combined apparent magnitude of about 6.5, it is at the limit of human eyesight and is just barely visible to the naked eye in ideal conditions. It is about 760 light years away from Earth.

References

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  2. Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
  3. 1 2 3 4 5 6 7 Budding, E.; Butland, R. (2011). "Observations and analysis of the system R Canis Majoris". Monthly Notices of the Royal Astronomical Society . 418 (3): 1764–73. Bibcode:2011MNRAS.418.1764B. doi: 10.1111/j.1365-2966.2011.19597.x .
  4. Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Washington. Bibcode:1953GCRV..C......0W.
  5. 1 2 3 Ammler-von Eiff, Matthias; Reiners, Ansgar (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics, 542: A116, arXiv: 1204.2459 , Bibcode:2012A&A...542A.116A, doi:10.1051/0004-6361/201118724, S2CID   53666672.
  6. Watson, Christopher (4 January 2010). "R Canis Majoris". AAVSO Website. American Association of Variable Star Observers . Retrieved 18 February 2014.
  7. Shobbrook, R. R. (December 2005). "Photometry of 20 eclipsing and ellipsoidal binary systems". The Journal of Astronomical Data. 11: 7. Bibcode:2005JAD....11....7S . Retrieved 15 November 2021.
  8. “Astrometric and light-travel time orbits to detect low-mass companions: a case study of the eclipsing system R Canis Majoris” "Ribas I, Arenou F, & Guinan EF - The Astronomical Journal, 123:2033-2041, 2002 April
  9. ""Near-infrared photometric studies of R Canis Majoris" Varricatt WP & Ashok NM - The Astronomical Journal, 17:2980-2997, 1999 June" . Retrieved 2009-03-08.