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
AE Aquarii - the first discovered white dwarf pulsar.
^ abCutri, 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.
^"AR Scorpii". International Variable Star Index. AAVSO. Retrieved 2023-03-13.
