AR Scorpii

Last updated
AR Scorpii

Artist’s impression of AR Scorpii.
Observation data
Epoch J2000       Equinox J2000
Constellation Scorpius
Right ascension 16h 21m 47.28s [1]
Declination −22° 53′ 10.3″ [1]
Characteristics
Apparent magnitude  (G)13.6 - 16.9 [2]
White dwarf
Evolutionary stage White dwarf
Red dwarf
Evolutionary stage Main sequence
Spectral type M5 [3]
Astrometry
Proper motion (μ)RA: 9.707 [4]   mas/yr
Dec.: −51.469 [4]   mas/yr
Parallax (π)8.4918 ± 0.0408  mas [4]
Distance 384 ± 2  ly
(117.8 ± 0.6  pc)
Details
White dwarf
Mass 0.8 [5]   M☉
Radius 0.01 [5]   R☉
Rotation 1.95 [3]   minutes
Red dwarf
Mass 0.28 - 0.45 [3]   M☉
Other designations
AR  Sco, 2MASS  J16214728-2253102
Database references
SIMBAD data

AR Scorpii (AR Sco) is a binary pulsar that consists of a white dwarf and a red dwarf. [3] It is located close to the ecliptic plane in the constellation Scorpius. Parallax measurements made by Gaia put the system at a distance of about 380 light-years (120 parsecs). [4]

A broadband optical light curve for AR Scorpii, plotted from Kepler data ARScoLightCurve.png
A broadband optical light curve for AR Scorpii, plotted from Kepler data

AR Scorpii is the first "white dwarf-pulsar" to be discovered. [7] Its unusual nature was first noticed by amateur astronomers. [8] The 3.56-hour period in AR Scorpii's light curve caused it to be misclassified as a Delta Scuti variable, but in 2016, this period was found to be the binary orbital period. In addition, the system shows very strong optical, ultraviolet, and radio pulsations originating from the red dwarf with a period of just 1.97 minutes, which is a beat period from the orbital rotation and the white dwarf spin. [3] These pulsations occur when a relativistic beam from the white dwarf sweeps across the red dwarf, which then reprocesses the beam into the observed electromagnetic energy. Although the white dwarf shows evidence of accretion in the past, at present it is not accreting significantly, and the system is powered by the spin-down of the white dwarf. [7] [5] The white dwarf's rotation will slow down on a timescale of 107 years. [5] It has a radius of about 7×103 km, [5] about the same size as Earth.

See also

Related Research Articles

<span class="mw-page-title-main">Pulsar</span> Rapidly rotating neutron star

A pulsar is a highly magnetized rotating neutron star that emits beams of electromagnetic radiation out of its magnetic poles. This radiation can be observed only when a beam of emission is pointing toward Earth, and is responsible for the pulsed appearance of emission. Neutron stars are very dense and have short, regular rotational periods. This produces a very precise interval between pulses that ranges from milliseconds to seconds for an individual pulsar. Pulsars are one of the candidates for the source of ultra-high-energy cosmic rays

<span class="mw-page-title-main">Wolf 424</span> Star in constellation of Virgo

Wolf 424 is a binary star system comprising two red dwarf stars at a distance of approximately 14.2 light-years from the Sun. It is located in the constellation Virgo, between the stars ε Virginis and ο Virginis.

<span class="mw-page-title-main">9 Aurigae</span> Multiple star system in the constellation Auriga

9 Aurigae is a star system in Auriga (constellation). It has an apparent magnitude of about 5, making it visible to the naked eye in many suburban skies. Parallax estimates made by the Hipparcos spacecraft put it at about 86 light-years from the solar system, although individual Gaia Data Release 3 parallaxes place all three components at 88 light years.

LS I +61 303 is a binary system containing a massive star and a compact object. The compact object is a pulsar and the system is around 7,000 light-years away.

<span class="mw-page-title-main">Teide 1</span> Brown dwarf in the constellation Taurus

Teide 1 is a brown dwarf located around 430 light years away in the Pleiades. It was the first brown dwarf to be confirmed. Its surface temperature is 2,600 ± 150 K, which is about half that of the Sun. Its luminosity is 0.08–0.05% of that of the Sun. It is estimated to have about the same age as Pleiades, giving a plausible range from 70 to 140 Myr.

AM Canum Venaticorum is a hydrogen-deficient cataclysmic variable binary star in the constellation of Canes Venatici. It is the type star of its class of variables, the AM Canum Venaticorum stars. The system consists of a white dwarf gaining matter via an accretion disk from a semi-degenerate or white dwarf companion.

<span class="mw-page-title-main">2MASS J0441+2301</span> Young star system in the constellation Taurus

2MASS J0441+2301 is a young quadruple system hosting a planetary-mass object, a red dwarf star and two brown dwarfs, approximately 470 light years away.

<span class="mw-page-title-main">HD 63032</span> Binary star system in the constellation Puppis

c Puppis, also known as HD 63032 and HR 3017, is a spectroscopic binary star in the constellation Puppis. Its apparent magnitude is of 3.61, making it the eight-brightest star in Puppis. The system is the brightest member of the open cluster NGC 2451, over two magnitudes brighter than every other star in the cluster. As the turnoff point of the cluster is currently around B7, the parameters of the system fit with cluster membership.

<span class="mw-page-title-main">G 9-38</span> Star in the constellation Cancer

G 9-38, also known as EI Cancri and GJ 1116, is a binary star system consisting of two M-type stars. At 16.7 light-years from the Sun, the system is relatively nearby.

ADS 7251 is a binary star system 6.33 parsecs from the Sun. The components are near-identical red dwarfs separated by 17″ in 2019.

<span class="mw-page-title-main">HP Lyrae</span> Variable star in the constellation Lyra

HP Lyrae is a variable star in the constellation Lyra, with a visual magnitude varying between 10.2 and 10.8. It will likely be an RV Tauri variable, an unstable post-AGB star losing mass before becoming a white dwarf.

<span class="mw-page-title-main">OGLE-LMC-CEP0227</span> Variable star in the Large Magellanic Cloud

OGLE-LMC-CEP0227 is an eclipsing binary and Cepheid variable star, pulsating every 3.8 days. The star, in the Large Magellanic Cloud, was the first Cepheid star system found to be orbiting exactly edge on.

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

S Cassiopeiae is a Mira variable and S-type star in the constellation Cassiopeia. It is an unusually cool star, rapidly losing mass and surrounded by dense gas and dust producing masers.

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

WZ Andromedae is an eclipsing binary star in the constellation Andromeda. Its maximum apparent visual magnitude is 11.6, but drops down to 12.00 during the main eclipse which occurs roughly every 16.7 hours.

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

AD Andromedae is an eclipsing binary in the constellation Andromeda. Its maximum apparent visual magnitude is 11.2, but it shows a decrease of 0.62 magnitudes during the main eclipse and 0.58 during the secondary one. It is classified as a Beta Lyrae variable star with a period of almost one day.

<span class="mw-page-title-main">CC Andromedae</span> Star in the constellation Andromeda

CC Andromedae is a variable star in the constellation Andromeda. It is a pulsating star of the Delta Scuti type, with an apparent visual magnitude that varies between 9.19 and 9.46 with a periodicity of 3 hours.

<span class="mw-page-title-main">CN Andromedae</span> Star in the constellation Andromeda

CN Andromedae is an eclipsing binary star in the constellation Andromeda. Its maximum apparent visual magnitude is 9.62 and drops down to a minimum of 10.2 during the main eclipse. It is classified as a Beta Lyrae variable with a period roughly of 0.4628 days.

<span class="mw-page-title-main">FF Andromedae</span> Star in the constellation Andromeda

FF Andromedae is a spectroscopic binary in the constellation Andromeda. It has a typical apparent visual magnitude of 10.4, but undergoes flare events that can increase its brightness by about a magnitude.

OAO 1657-415 is a high-mass X-ray binary (HMXB) located in the constellation of Scorpius, over 20,000 light years away. It is believed to be composed of a compact object and a highly evolved massive slash star, with Wolf–Rayet and O-type features in its spectrum, with a spectral type of Ofpe/WN9. OAO 1657-415 is special as it has the largest eccentricity and orbital period of any HMXB, and also because its donor star is much more evolved than many other HMXB donor stars.

<span class="mw-page-title-main">HR 3562</span> Visual binary in constellation Vela

HR 3562 is a visual binary consisting of a bluish-white hued variable star and a Sun-like secondary star in the southern constellation of Vela. It has the variable-star designation IY Velorum. With an apparent magnitude of 6.26, the brighter primary is near the limit for naked eye visibility. The fainter companion has an apparent magnitude of 12.639 and can be observed with a telescope with an aperture of 76 mm or wider. It is located approximately 373 parsecs (1,220 ly) distant according to Gaia EDR3 parallax measurements, and is receding away from the Solar System at a heliocentric radial velocity of 22.0 km/s.

References

  1. 1 2 Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues. 2246: II/246. Bibcode:2003yCat.2246....0C.
  2. ↑ "AR Scorpii". International Variable Star Index. AAVSO . Retrieved 2023-03-13.
  3. 1 2 3 4 5 Marsh, T. R.; et al. (2016). "A radio-pulsing white dwarf binary star". Nature. 537 (7620): 374–377. arXiv: 1607.08265 . Bibcode:2016Natur.537..374M. doi:10.1038/nature18620. PMID   27462808. S2CID   4451512.
  4. 1 2 3 4 Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics . 616. A1. arXiv: 1804.09365 . Bibcode: 2018A&A...616A...1G . doi: 10.1051/0004-6361/201833051 . Gaia DR2 record for this source at VizieR.
  5. 1 2 3 4 5 Singh, K. K.; Meintjes, P. J.; Yadav, K. K. (2021). "Properties of white dwarf in the binary system AR Scorpii and its observed features". Modern Physics Letters A. 36 (13). arXiv: 2103.11602 . Bibcode:2021MPLA...3650096S. doi:10.1142/S0217732321500966. S2CID   232307204.
  6. ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
  7. 1 2 Buckley, D. A. H.; Meintjes, P. J.; Potter, S. B.; Marsh, T. R.; Gänsicke, B. T. (2017-01-23). "Polarimetric evidence of a white dwarf pulsar in the binary system AR Scorpii". Nature Astronomy. 1 (2): 0029. arXiv: 1612.03185 . Bibcode:2017NatAs...1E..29B. doi:10.1038/s41550-016-0029. S2CID   15683792.
  8. ↑ Hambsch, Franz-Josef (15 August 2016). "Amateurs Help Discover Pulsing White Dwarf". Sky and Telescope.
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.