Implications of the HST/FGS parallaxof SS Cygnion the disc instability model

Simple item page
dc.contributor.authorSchreiber, M R
dc.contributor.authorGänsicke, B T
dc.date.accessioned2021-10-08T11:00:59Z
dc.date.available2021-10-08T11:00:59Z
dc.date.issued2002
dc.description.abstractWe analyse the consequences of the recently measured parallax of SS Cygni (Harrison et al. 1999) on the accretion disc limit cycle model. Using the observed long term light curve of SS Cyg and d = 166 ± 12 pc, we obtain for the mean mass transfer rate M˙ tr = 4.2±1.7×1017 g s−1. In addition, we calculate the vertical structure of the accretion disc taking into account heating of the outer disc by the stream impact. Comparing the mean accretion rate derived from the observations with the calculated critical mass transfer rate, we find that the disc instability model disagrees with the observed long term light curve of SS Cyg as M˙ tr is greater or similar to the critical mass transfer rate. The failure of the model indicated by this result can be confirmed by considering that the accretion rate at the onset of the decline should be exactly equal to the value critical for stability. In contrast to this prediction of the model, we find that the accretion rate required to explain the observed visual magnitude at the onset of the decline must be significantly higher than the critical mass transfer rate. Our results strongly suggest that either the usually assumed temperature dependence of the viscosity parameter α is not a realistic description of the disc viscosity, that the mass transfer rate in
dc.identifier.apacitationSchreiber, M. R., & Gänsicke, B. T. (2002). Implications of the HST/FGS parallaxof SS Cygnion the disc instability model. <i>Astronomy and Astrophysics</i>, 382(1), 124 - 129. http://hdl.handle.net/11427/35062en_ZA
dc.identifier.chicagocitationSchreiber, M R, and B T Gänsicke "Implications of the HST/FGS parallaxof SS Cygnion the disc instability model." <i>Astronomy and Astrophysics</i> 382, 1. (2002): 124 - 129. http://hdl.handle.net/11427/35062en_ZA
dc.identifier.citationSchreiber, M.R. & Gänsicke, B.T. 2002. Implications of the HST/FGS parallaxof SS Cygnion the disc instability model. <i>Astronomy and Astrophysics.</i> 382(1):124 - 129. http://hdl.handle.net/11427/35062en_ZA
dc.identifier.issn0004-6361
dc.identifier.issn1432-0746
dc.identifier.ris TY - Journal Article AU - Schreiber, M R AU - Gänsicke, B T AB - We analyse the consequences of the recently measured parallax of SS Cygni (Harrison et al. 1999) on the accretion disc limit cycle model. Using the observed long term light curve of SS Cyg and d = 166 ± 12 pc, we obtain for the mean mass transfer rate M˙ tr = 4.2±1.7×1017 g s−1. In addition, we calculate the vertical structure of the accretion disc taking into account heating of the outer disc by the stream impact. Comparing the mean accretion rate derived from the observations with the calculated critical mass transfer rate, we find that the disc instability model disagrees with the observed long term light curve of SS Cyg as M˙ tr is greater or similar to the critical mass transfer rate. The failure of the model indicated by this result can be confirmed by considering that the accretion rate at the onset of the decline should be exactly equal to the value critical for stability. In contrast to this prediction of the model, we find that the accretion rate required to explain the observed visual magnitude at the onset of the decline must be significantly higher than the critical mass transfer rate. Our results strongly suggest that either the usually assumed temperature dependence of the viscosity parameter α is not a realistic description of the disc viscosity, that the mass transfer rate in DA - 2002 DB - OpenUCT DP - University of Cape Town IS - 1 J1 - Astronomy and Astrophysics LK - https://open.uct.ac.za PY - 2002 SM - 0004-6361 SM - 1432-0746 T1 - Implications of the HST/FGS parallaxof SS Cygnion the disc instability model TI - Implications of the HST/FGS parallaxof SS Cygnion the disc instability model UR - http://hdl.handle.net/11427/35062 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/35062
dc.identifier.vancouvercitationSchreiber MR, Gänsicke BT. Implications of the HST/FGS parallaxof SS Cygnion the disc instability model. Astronomy and Astrophysics. 2002;382(1):124 - 129. http://hdl.handle.net/11427/35062.en_ZA
dc.language.isoeng
dc.publisher.departmentDepartment of Astronomy
dc.publisher.facultyFaculty of Science
dc.sourceAstronomy and Astrophysics
dc.source.journalissue1
dc.source.journalvolume382
dc.source.pagination124 - 129
dc.source.urihttps://dx.doi.org/10.1051/0004-6361:20011627
dc.subject.otheraccretion
dc.subject.otheraccretion discs
dc.subject.otherbinaries
dc.subject.otherclose
dc.subject.otherstars
dc.subject.otherindividual
dc.subject.otherSS Cygni
dc.subject.othernovae
dc.subject.othercataclysmic variables
dc.titleImplications of the HST/FGS parallaxof SS Cygnion the disc instability model
dc.typeJournal Article
uct.type.publicationResearch
uct.type.resourceJournal Article
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
SchreiberMR_ImplicationsHST_2002.pdf
Size:
538.16 KB
Format:
Adobe Portable Document Format
Description:
Download
Collections
Journal Articles