RR Centauri

Last updated
RR Centauri
RR Cen Eclipse Phase.png
Light curve of RR Cen.
Observation data
Epoch J2000       Equinox J2000
Constellation Centaurus
Right ascension 14h 16m 57.22s [1]
Declination −57° 51′ 15.6″ [1]
Apparent magnitude  (V)7.29 [2] (7.27 - 7.68 [3] )
Characteristics
Spectral type F0 V [4]
U−B color index +0.05 [2]
B−V color index +0.36 [2]
Variable type W Uma [3]
Astrometry
Radial velocity (Rv)-16.0 [5]  km/s
Proper motion (μ)RA: -52.00 [6]   mas/yr
Dec.: -22.63 [6]   mas/yr
Parallax (π)10.16 ± 0.61  mas [6]
Distance 320 ± 20  ly
(98 ± 6  pc)
Absolute magnitude  (MV)+1.882 [4]
Orbit [7]
PrimaryRR Cen1
CompanionRR Cen2
Period (P)0.60569 days
Semi-major axis (a)3.92 ± 0.19 R☉
Eccentricity (e)0
Inclination (i)81.00 ± 0.44°
Details [7]
RR Cen1
Mass 1.82 ± 0.26  M☉
Radius 2.1 ± 0.01  R☉
Luminosity 8.89  L☉
Temperature 6,912  K
RR Cen2
Mass 0.38 ± 0.06  M☉
Radius 1.05 ± 0.03  R☉
Luminosity2.2  L☉
Temperature 6,891 ± 13  K
Other designations
RR  Cen, 2MASS  J14165721-5751156, HD  124689, HIP  69779, SAO  241587, TYC  8686-210-1, Cordoba Durchmusterung CD-57 5498 [1]
Database references
SIMBAD data

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. [6]

The system is a contact binary of the W UMa type - two stars in physical contact whose two components share a gaseous envelope. Its spectral type is A9V or F0V. [1] The binary nature of the star was discovered in 1896 by the Scottish-South African astronomer Alexander Roberts, so the system has been well observed for over a century. [8] The primary component has a mass of 1.82 solar masses, an effective temperature of around 6900 K, and a radius somewhat larger than twice the solar radius. [7] The secondary component is 0.39 solar masses, giving a mass ratio of the system (q) of 0.210. the secondary has a temperature of about 6890 K and a radius is almost equal to the solar radius.

The orbital period of this system is 0.6057 days (14.53 hours). Recent calculations by astronomers from the Chinese Academy of Sciences show a possible cyclic variation in orbital period over 65.1 ± 0.4 years whose amplitude is 0.0124 ± 0.0007 days. [7] The origin of this periodic variation could be due to the gravitational influence of a third object yet observed. Superimposed on this variation seems to be a secular increase in the period of 1.21 x 10 –7 days per year, suggesting that there is transfer of stellar mass from secondary to primary component. If this increase is confirmed, RR Centauri may evolve into a single rapidly rotating star.

RR Centauri is also an eclipsing binary, whose apparent brightness varies by around 0.41 magnitudes. [7]

Related Research Articles

<span class="mw-page-title-main">IM Pegasi</span> Star in the constellation Pegasus

IM Pegasi is a variable binary star system approximately 329 light-years away in the constellation of Pegasus. With an apparent magnitude of 5.7, it is visible to the naked eye. Increased public awareness of it is due to its use as the guide star for the Gravity Probe B general relativity experiment. It was chosen for this purpose because its microwave radio emissions are observable with a large radio telescope network on the ground in such a manner that its precise position can be related by interferometry to distant quasars.

Xi Ursae Majoris is a star system in the constellation of Ursa Major. It has the traditional name Alula Australis; Xi Ursae Majoris is the Bayer designation, which is Latinised from ξ Ursae Majoris and abbreviated Xi UMa or ξ UMa. It was the first visual double star for which an orbit was calculated, when it was computed by Félix Savary in 1828. It is also a variable star with a small amplitude. Xi Ursae Majoris is found in the left hind paw of the Great Bear.

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

AR Aurigae, also known by its Flamsteed designation 17 Aurigae, is a binary star in the constellation Auriga. Based on parallax measurements made by the Hipparcos spacecraft, it is approximately 461 light-years from Earth.

<span class="mw-page-title-main">44 Boötis</span> Triple star system in the constellation Boötes

44 Boötis or i Boötis is a triple star system in the constellation Boötes. It is approximately 41.6 light years from Earth.

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

Tau Canis Majoris is a multiple star system in the constellation Canis Major. It is approximately 5,000 light years distant from Earth and is the brightest member of the open cluster NGC 2362.

<span class="mw-page-title-main">Nu Centauri</span> Binary star system in the constellation Centaurus

Nu Centauri, Latinized from ν Centauri, is a binary star system in the southern constellation of Centaurus. The combined apparent visual magnitude of the pair is +3.41, making this one of the brightest members of the constellation. Based upon parallax measurements made during the Hipparcos mission, this star system is located at a distance of roughly 437 light-years from Earth. The margin of error for this distance is about 2%, which is enough to give an error in distance of ±10 light years.

<span class="mw-page-title-main">HR 5553</span> Binary star system in the constellation Boötes

HR 5553 is a binary star system located thirty-eight light-years away from the Sun, in the northern constellation Boötes. It has the variable star designation DE Boötis, and is classified as an RS Canum Venaticorum variable that ranges in apparent visual magnitude from 5.97 down to 6.04, which is bright enough to be dimly visible to the naked eye. The system is drifting closer to the Sun with a radial velocity of −30 km/s, and is expected to come as close as 26.9 light-years in 210,000 years.

<span class="mw-page-title-main">II Pegasi</span> Star in the constellation Pegasus

II Pegasi is a binary star system in the constellation of Pegasus with an apparent magnitude of 7.4 and a distance of 130 light-years. It is a very active RS Canum Venaticorum variable, a close binary system with active starspots.

<span class="mw-page-title-main">S Antliae</span> Star in the constellation Antlia

S Antliae is a W Ursae Majoris-type eclipsing binary star in Antlia.

<span class="mw-page-title-main">YZ Cassiopeiae</span> Triple star system in the constellation Cassiopeia

YZ Cassiopeiae is a star system 103.8 parsecs (339 ly) away from Earth, in the constellation Cassiopeia. It comprises three stars: an eclipsing Algol-type binary and a visually fainter star about 3000 AU distant.

<span class="mw-page-title-main">3 Camelopardalis</span> Star in the constellation Camelopardalis

3 Camelopardalis is a spectroscopic and visual binary in the constellation Camelopardalis. It is approximately 496 light years from Earth.

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

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

<span class="mw-page-title-main">Epsilon Coronae Australis</span> Variable star in the constellation Corona Australis

Epsilon Coronae Australis, is a star system located in the constellation Corona Australis. Varying in brightness between apparent magnitudes of 4.74 to 5 over 14 hours, it is the brightest W Ursae Majoris variable in the night sky.

<span class="mw-page-title-main">V831 Centauri</span> Star in the constellation Centaurus

V831 Centauri is a multiple star system in the constellation Centaurus. It is visible to the naked eye with an apparent visual magnitude that ranges from 4.49 down to 4.66. The system is located at a distance of approximately 380 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +12 km/s. It is a likely member of the Lower Centaurus Crux concentration of the Sco OB2 association of co-moving stars.

<span class="mw-page-title-main">TV Pictoris</span> Star in the constellation Pictor

TV Pictoris is a rotating ellipsoidal variable star in the constellation Pictor. It ranges between apparent magnitude 7.37 - 7.53 over a period of 0.85 days. It was first discovered to be variable in 1987. The system is inclined at an angle of 54 degrees to observers on Earth. It is composed of a primary star that has a radius 4.3 times that of the sun and 1.2 times its mass, and an effective (surface) temperature of 8300 K, and a secondary star with a radius 2.1 times that of the sun and 40% of its mass, and an effective temperature of 7000 K. Both stars are less massive than expected for a main sequence star of their temperatures. The secondary rotates much faster than the primary.

<span class="mw-page-title-main">AB Andromedae</span> Binary star in the Andromeda constellation

AB Andromedae is a binary star in the constellation Andromeda. Paul Guthnick and Richard Prager discovered that the star is an eclipsing binary in 1927. Its maximum apparent visual magnitude is 9.49 but shows a variation in brightness down to a magnitude of 10.46 in a periodic cycle of roughly 8 hours. The observed variability is typical of W Ursae Majoris variable stars, so the two stars in this system form a contact binary.

<span class="mw-page-title-main">QX Andromedae</span> Eclipsing binary star system in the constellation Andromeda

QX Andromedae is an eclipsing binary in the constellation Andromeda. It varies from a maximum apparent visual magnitude of 11.28 to a minimum of 11.50. Since it is impossible to specify the onset time of the eclipses, it is classified as a W Ursae Majoris variable star. It is also observed as an X-ray source and is a member of the open cluster NGC 752.

<span class="mw-page-title-main">AE Phoenicis</span> Star in the constellation Phoenix

AE Phoenicis is a variable star in the constellation of Phoenix. An eclipsing binary, its apparent magnitude has a maximum of 7.56, dimming to 8.25 during primary eclipse and 8.19 during secondary eclipse. From parallax measurements by the Gaia spacecraft, the system is located at a distance of 168 light-years from Earth.

<span class="mw-page-title-main">V752 Centauri</span> Star in the constellation Centaurus

V752 Centauri is multiple star system and variable star in the constellation of Centaurus. An eclipsing binary, its apparent magnitude has a maximum of 9.10, dimming to 9.66 during primary eclipse and 9.61 during secondary eclipse. Its variability was discovered by Howard Bond in 1970. From parallax measurements by the Gaia spacecraft, the system is located at a distance of 410 light-years from Earth.

<span class="mw-page-title-main">V471 Tauri</span> Variable star in the constellation Taurus

V471 Tauri is a eclipsing variable star in the constellation of Taurus. The star has a visual magnitude of 9 which makes it impossible to see with the naked eye. It is around 155 light-years away from the Solar System.

References

  1. 1 2 3 4 "V* RR Cen -- Eclipsing binary of W UMa type (contact binary)". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2016-02-27.
  2. 1 2 3 Loden, L.O. (1979). "Continued studies of loose clusterings in the Southern Milky Way". Astronomy and Astrophysics Supplement. 38: 355. Bibcode:1979A&AS...38..355L.
  3. 1 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.
  4. 1 2 Eker, Z.; Bilir, S.; Yaz, E.; Demircan, O.; Helvaci, M. (2009). "New absolute magnitude calibrations for W Ursa Majoris type binaries". Astronomische Nachrichten. 330 (1): 68–76. arXiv: 0807.4989 . Bibcode:2009AN....330...68E. doi:10.1002/asna.200811041. S2CID   15071352.
  5. ↑ Bilir, S; Karatas, Y; Demircan, O; Eker, Z (2005). "Kinematics of W Ursae Majoris type binaries and evidence of the two types of formation". Monthly Notices of the Royal Astronomical Society. 357 (2): 497–517. arXiv: astro-ph/0411291 . Bibcode:2005MNRAS.357..497B. doi:10.1111/j.1365-2966.2005.08609.x. S2CID   16274339.
  6. 1 2 3 4 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. S2CID   18759600.
  7. 1 2 3 4 5 Yuan-Gui, Y.; Sheng-Bang, Q.; Li-Ying, Z.; Jia-Jia, H.; Jin-Zhao, Y (2005). "Photometric Investigations of Three Short-Period Binary Systems: GSC 0763–0572, RR Centauri, and Epsilon Coronae Australis". Publications of the Astronomical Society of Japan. 57 (6): 983–993. Bibcode:2005PASJ...57..983Y. doi: 10.1093/pasj/57.6.983 .
  8. ↑ Roberts, Alexander (1903). "Determination of the Orbital Elements of RR Centauri from the Observed Light Curve". Monthly Notices of the Royal Astronomical Society. 63 (8): 540–549. Bibcode:1903MNRAS..63..536R. doi: 10.1093/mnras/63.8.527 .
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.