Browsing by Author "Challis, P."

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    HIGH-AMPLITUDE δ-SCUTIS IN THE LARGE MAGELLANIC CLOUD
    (2010) Garg, A.; Cook, K. H.; Nikolaev, S.; Huber, M. E.; Rest, A.; Becker, A. C.; Challis, P.; Clocchiatti, A.; Miknaitis, G.; Minniti, D.; Morelli, L.; Olsen, K.; Prieto, J. L.; Suntzeff, N. B.; Welch, D. L.; Wood-Vasey, W. M.
    We present 2323 high-amplitude delta-Scuti (HADS) candidates discovered in the Large Magellanic Cloud by the SuperMACHO survey (Rest et al.). Frequency analyses of these candidates reveal that several are multimode pulsators, including 119 whose largest amplitude of pulsation is in the fundamental (F) mode and 19 whose largest amplitude of pulsation is in the first overtone (FO) mode. Using Fourier decomposition of the HADS light curves, we find that the period-luminosity (PL) relation defined by the FO pulsators does not show a clear separation from the PL relation defined by the F pulsators. This differs from other instability strip pulsators such as type c RR Lyrae. We also present evidence for a larger amplitude, subluminous population of HADS similar to that observed in Fornax.
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    LIGHT. CURVES. OF. 213 TYPE. Ia SUPERNOVAE. FROM. THE. ESSENCE. SURVEY
    (2016) Narayan, G.; Rest, A.; Tucker, B.; Foley, R.; Wood, W.; Challis, P.; Stubbs, C.; Kirshner, R.; Aguilera, C.; Clocchiatti, Alejandro; Becker, A.; Blondin, S.; Covarrubias, R.; Damke, G.; Davis, T.; Filippenko, A.
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    Supernova 2011D in UGC 2498
    (2011) Narla, A.; Cenko, S. B.; Li, W.; Filippenko, A. V.; Howerton, S.; Drake, A. J.; Djorgovski, S. G.; Mahabal, A.; Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, Marcio; Beshore, E. C.; Larson, S. M.; Christensen, E.; Marion, G. H.; Challis, P.; Berlind, P.
    Via public images from the Catalina Sky Survey (CSS). 2011 UT R.A. (2000.0) Decl. Mag. Offset Observers Jan. 5.09 3 02 14.58 +17 20 58.9 18.2 33".8 E, 14".7 N CSS Jan. 6.30 3 02 14.53 +17 20 58.3 18.2 34".4 E, 14".8 N KAIT Additional magnitudes for 2011D: 2010 Dec. 8.32 UT, [19.3 (KAIT); 10.19, [19.4 (CSS); 2011 Jan. 7.21, 18.2 (KAIT); 8.13, 17.8 (S. Howerton, remotely with the LB-1 0.6-m telescope near Rodeo, NM, U.S.A.). Drake notes that the presumed host galaxy, UGC 2498, has redshift z = 0.0231. G. H. Marion and P. Challis, Harvard-Smithsonian Center for Astrophysics (CfA), on behalf of the CfA Supernova Group, report that a spectrum (range 340-740 nm) was obtained of 2011D on Jan. 8 UT by P. Berlind with the F. L. Whipple Observatory 1.5-m telescope (+ FAST). Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows that 2011D is a type-IIb supernova a few days before maximum light....