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dc.contributor.authorWang, Ting-gui
dc.contributor.authorJiang, Ning
dc.contributor.authorGe, Jian
dc.contributor.authorCutri, Roc M.
dc.contributor.authorJiang, Peng
dc.contributor.authorSheng, Zhengfeng
dc.contributor.authorZhou, Hongyan
dc.contributor.authorBauer, James
dc.contributor.authorMainzer, Amy
dc.contributor.authorWright, Edward L.
dc.date.accessioned2020-01-31T19:34:22Z
dc.date.available2020-01-31T19:34:22Z
dc.date.issued2019-11-14
dc.identifier.citationTing-gui Wang et al 2019 ApJL 886 L5en_US
dc.identifier.issn2041-8205
dc.identifier.doi10.3847/2041-8213/ab53ed
dc.identifier.urihttp://hdl.handle.net/10150/636798
dc.description.abstractWe report the detection of a large-amplitude MIR outburst in the white dwarf (WD) 0145+234 in the NEOWISE Survey data. The source had a stable MIR flux before 2018, and was brightened by about 1.0 magnitude in the W1 and W2 bands within half a year and has been continuously brightening since then. No significant variations are found in the optical photometry data during the same period. This suggests that this MIR outburst is caused by recent replenishing or redistribution of dust, rather than intrinsic variations of the WD. Spectral energy distribution modeling of 0145+234 suggests that there was already a dust disk around the WD in the quiescent state, and both of the temperature and surface area of the disk evolved rapidly since the outburst. The dust temperature was 1770 K in the initial rising phase, close to the sublimation temperature of silicate grains, and gradually cooled down to around 1150 K, while the surface area increased by a factor of about six during the same period. The inferred closest distance of dust to the WD is within the tidal disruption radius of a gravitationally bounded asteroid. We estimated the dust mass to be between 3;;10(15) and 3;;10(17)?/(1 g cm(?3)) kg for silicate grains of a power-law size distribution with a high cutoff size from 0.1 to 1000 ?m. We interpret this as a possible tidal breakup of an exoasteroid by the WD. Further follow-up observations of this rare event may provide insights on the origin of dust disk and metal pollution in some WDs.en_US
dc.description.sponsorshipChinese Science FoundationNational Natural Science Foundation of China [NSFC-11833007, 11421303]; National Aeronautics and Space AdministrationNational Aeronautics & Space Administration (NASA); Planetary Science Division of the National Aeronautics and Space Administrationen_US
dc.language.isoenen_US
dc.publisherIOP PUBLISHING LTDen_US
dc.rightsCopyright © 2019. The American Astronomical Society. All rights reserved.en_US
dc.subjectWhite dwarf starsen_US
dc.subjectCircumstellar dusten_US
dc.subjectInfrared excessen_US
dc.subjectVariable radiation sourcesen_US
dc.titleAn Ongoing Mid-infrared Outburst in the White Dwarf 0145+234: Catching in Action the Tidal Disruption of an Exoasteroid?en_US
dc.typeArticleen_US
dc.contributor.departmentUniv Arizonaen_US
dc.identifier.journalASTROPHYSICAL JOURNAL LETTERSen_US
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en_US
dc.eprint.versionFinal published versionen_US
dc.source.volume886
dc.source.issue1
dc.source.beginpageL5
refterms.dateFOA2020-01-31T19:34:24Z


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