The 2001 Superoutburst of WZ Sagittae

Simple item page
dc.contributor.authorPatterson, Joseph
dc.contributor.authorMasi, Gianluca
dc.contributor.authorRichmond, Michael W.
dc.contributor.authorMartin, Brian
dc.contributor.authorBeshore, Edward
dc.contributor.authorSkillman, David R.
dc.contributor.authorKemp, Jonathan
dc.contributor.authorVanmunster, Tonny
dc.contributor.authorRea, Robert
dc.contributor.authorAllen, William
dc.contributor.authorDavis, Stacey
dc.contributor.authorDavis, Tracy
dc.contributor.authorHenden, Arne A.
dc.contributor.authorStarkey, Donn
dc.contributor.authorFoote, Jerry
dc.contributor.authorOksanen, Arto
dc.contributor.authorCook, Lewis M.
dc.contributor.authorFried, Robert E.
dc.contributor.authorHusar, Dieter
dc.contributor.authorNovák, Rudolf
dc.contributor.authorCampbell, Tut
dc.contributor.authorRobertson, Jeff
dc.contributor.authorKrajci, Thomas
dc.contributor.authorPavlenko, Elena
dc.contributor.authorMirabal, Nestor
dc.contributor.authorNiarchos, Panos G.
dc.contributor.authorBrettman, Orville
dc.contributor.authorWalker, Stan
dc.date.accessioned2020-09-09T17:17:42Z
dc.date.available2020-09-09T17:17:42Z
dc.date.issued2002-06-10
dc.description.abstractWe report the results of a worldwide campaign to observe WZ Sagittae during its 2001 superoutburst. After a 23 yr slumber at V = 15.5, the star rose within 2 days to a peak brightness of 8.2, and showed a main eruption lasting 25 days. The return to quiescence was punctuated by 12 small eruptions, of ~1 mag amplitude and 2 day recurrence time; these "echo outbursts" are of uncertain origin, but somewhat resemble the normal outbursts of dwarf novae. After 52 days, the star began a slow decline to quiescence. Periodic waves in the light curve closely followed the pattern seen in the 1978 superoutburst: a strong orbital signal dominated the first 12 days, followed by a powerful common superhump at 0.05721(5) day, 0.92(8)% longer than Porb. The latter endured for at least 90 days, although probably mutating into a "late" superhump with a slightly longer mean period [0.05736(5) day]. The superhump appeared to follow familiar rules for such phenomena in dwarf novae, with components given by linear combinations of two basic frequencies: the orbital frequency ωo and an unseen low frequency Ω, believed to represent the accretion disk's apsidal precession. Long time series reveal an intricate fine structure, with ~20 incommensurate frequencies. Essentially all components occurred at a frequency nωo - mΩ, with m = 1, ..., n. But during its first week, the common superhump showed primary components at nωo - Ω, for n = 1, 2, 3, 4, 5, 6, 7, 8, 9 (i.e., m = 1 consistently); a month later, the dominant power shifted to components with m = n - 1. This may arise from a shift in the disk's spiral‐arm pattern, likely to be the underlying cause of superhumps. The great majority of frequency components are redshifted from the harmonics of ωo, consistent with the hypothesis of apsidal advance (prograde precession). But a component at 35.42 cycles day⁻¹ suggests the possibility of a retrograde precession at a different rate, probably N = 0.13 ± 0.02 cycles day⁻¹. The eclipses permit measuring the location and brightness of the mass‐transfer hot spot. The disk must be very eccentric and nearly as large as the white dwarf's Roche lobe. The hot‐spot luminosity exceeds its quiescent value by a factor of up to 60. This indicates that enhanced mass transfer from the secondary plays a major role in the eruption.en_US
dc.description.sponsorshipWe would like to express our gratitude to T. Ohshima for his brilliant discovery of WZ Sge on its steep rise to maximum; T. Kato and the VSNET team for their boundless energy in organizing many of the observations from variable-star astronomers around the world, keeping the communications fast and the excitement high; John Cannizzo, Matt Wood, and John Thorstensen for discussions; Jim Kern, Matt Aggleton, Kevin Beaulieu, Dustin Crabtree, Brad Conrad, Marko Moilanen, Harri Hyvonen, Cindy Foote, Jennie McCormick, Fred Velthuis, Tim Hager, Kosmas Gazeas, Alexander Yushchenko, James Hannon, Dan Kaiser, Franco Mallia, and Lasse Jensen for other contributions of data to this enterprise; and a wise and anonymous referee for suggestions. This research was supported in part by grants 00-98254 from the NSF and GG 00-42 from the Research Corporation.en_US
dc.description.urihttps://iopscience.iop.org/article/10.1086/341696en_US
dc.format.extent27 pagesen_US
dc.genrejournal articlesen_US
dc.identifierdoi:10.13016/m2boyv-osf9
dc.identifier.citationJoseph Patterson et al., The 2001 Superoutburst of WZ Sagittae, PASP 114 721 (2002), doi: https://doi.org/10.1086/341696en_US
dc.identifier.urihttps://doi.org/10.1086/341696
dc.identifier.urihttp://hdl.handle.net/11603/19619
dc.language.isoen_USen_US
dc.publisherIOPen_US
dc.relation.isAvailableAtThe University of Maryland, Baltimore County (UMBC)
dc.relation.ispartofUMBC Physics Department Collection
dc.relation.ispartofUMBC Joint Center for Earth Systems Technology (JCET)
dc.relation.ispartofUMBC Center for Space Sciences and Technology (CSST) / Center for Research and Exploration in Space Sciences & Technology II (CRSST II)
dc.rightsThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.
dc.rightsPublic Domain Mark 1.0*
dc.rightsThis work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law
dc.rights.urihttp://creativecommons.org/publicdomain/mark/1.0/*
dc.titleThe 2001 Superoutburst of WZ Sagittaeen_US
dc.typeTexten_US

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Patterson_2002_PASP_114_721.pdf
Size:
791.04 KB
Format:
Adobe Portable Document Format
Description:
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
2.56 KB
Format:
Item-specific license agreed upon to submission
Description:
Download

Collections

UMBC Physics Department
UMBC Center for Space Sciences and Technology (CSST) / Center for Research and Exploration in Space Sciences & Technology II (CRSST II)
UMBC Joint Center for Earth Systems Technology (JCET)