Open AccessWZ Sagittae as a DQ Herculis star
Author(s) -
Lasota JeanPierre,
Kuulkers Erik,
Charles Phil
Publication year - 1999
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1999.02485.x
Subject(s) - physics , astrophysics , white dwarf , beat (acoustics) , rotation period , astronomy , magnetosphere , spinning , intermediate polar , oscillation (cell signaling) , plasma , stars , optics , quantum mechanics , biology , genetics , engineering , mechanical engineering
We argue that quiescent WZ Sge is a rapidly spinning magnetic rotator in which most of the matter transferred from the secondary is ejected from the system. Assuming that the observed 27.87‐s oscillation period results from the spinning white dwarf, we propose that the other observed principal period of 28.96 s is a beat caused by reprocessing of the rotating white dwarf beam on plasma blobs in Keplerian rotation at the outer disc rim. The weaker, transient, 29.69‐s period is identified as a beat with the Keplerian period of the magnetosphere. WZ Sge evolves through a cycle of spin‐up and spin‐down phases. During the spin‐down phase it is a DQ Her star; during the spin‐up phase it should be a ER UMa star.