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dc.contributor.authorBarnes, J R
dc.contributor.authorCollier Cameron, A
dc.date.accessioned2011-12-20T16:01:25Z
dc.date.available2011-12-20T16:01:25Z
dc.date.issued2001-09-21
dc.identifier.citationBarnes , J R & Collier Cameron , A 2001 , ' Starspot patterns on the M dwarfs HK Aqr and RE 1816+541 ' , Monthly Notices of the Royal Astronomical Society , vol. 326 , no. 3 , pp. 950-958 . https://doi.org/10.1046/j.1365-8711.2001.04649.x
dc.identifier.issn0035-8711
dc.identifier.urihttp://hdl.handle.net/2299/7430
dc.description.abstractWe present the first Doppler images of two M dwarfs in the solar neighbourhood. Late-type dwarfs are generally too faint to enable spectra with sufficient signal-to-noise (SIN) ratios for Doppler imaging to be obtained in short enough exposure times. Using the large number of photospheric absorption lines in each spectrum, we apply least-squares deconvolution to derive composite line profiles with S/N ratios of 100-500. The surface images of HK Aqr reveal a moderately spotted surface, with the majority of starspots appearing at low latitudes, whereas RE 1816 +541 exhibits spots at all latitudes. Neither star shows significant evidence for the oft-observed polar spot. Despite the boost in S/N ratio achieved with the least-squares deconvolution technique, the images are not consistent enough to determine reliably the magnitude of differential rotation. Nevertheless, the images are consistent enough to place upper limits on the rate of surface shear.en
dc.format.extent9
dc.language.isoeng
dc.relation.ispartofMonthly Notices of the Royal Astronomical Society
dc.subjectline : profiles
dc.subjectmethods : data analysis
dc.subjectstars : activity
dc.subjectstars : imaging
dc.subjectstars : late-type
dc.subjectstars : spots
dc.subjectDIFFERENTIAL ROTATION
dc.subjectPLAGE ACTIVITY
dc.subjectRAPID ROTATOR
dc.subjectGLIESE-890
dc.subjectPROMINENCES
dc.subjectRE-1816+541
dc.titleStarspot patterns on the M dwarfs HK Aqr and RE 1816+541en
dc.contributor.institutionSchool of Physics, Astronomy and Mathematics
dc.description.statusPeer reviewed
rioxxterms.versionofrecord10.1046/j.1365-8711.2001.04649.x
rioxxterms.typeJournal Article/Review
herts.preservation.rarelyaccessedtrue


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