A Tale of Two Impostors: SN2002kg and SN1954J in NGC 2403
Abstract
We describe new results on two supernova impostors in NGC 2403, SN 1954J(V12) and SN 2002kg(V37). For the famous object SN 1954J, we combine four critical observations: its current SED, its Hα emission line profile, the Ca II triplet in absorption in its red spectrum, and the brightness compared to its pre-event state. Together, these strongly suggest that the survivor is now a hot supergiant with T ~ 20,000 K, a dense wind, substantial circumstellar extinction, and a G-type supergiant companion. The hot star progenitor of V12's giant eruption was likely in the post-red supergiant stage and had already shed a lot of mass. V37 is a classical LBV/S Dor variable. Our photometry and spectra observed during and after its eruption show that its outburst was an apparent transit on the HR Diagram due to enhanced mass loss and the formation of a cooler, dense wind. V37 is an evolved hot supergiant at ≈10^6 L⊙ with a probable initial mass of 60–80 M⊙.
Additional Information
© 2017 The American Astronomical Society. Received 2017 July 28; revised 2017 September 1; accepted 2017 September 1; published 2017 October 17. Based on observations with the Multiple Mirror Telescope, a joint facility of the Smithsonian Institution and the University of Arizona, and on observations obtained with the Large Binocular Telescope (LBT), an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners include The University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota, and University of Virginia. Research by R.H. and K.D. on massive stars is supported by the National Science Foundation AST-1109394. This paper uses data from the MODS1 and MODS2 spectrographs built with funding from NSF grant AST-9987045 and the NSF Telescope System Instrumentation Program (TSIP), with additional funds from the Ohio Board of Regents and the Ohio State University Office of Research. Facilities: MMT/Hectospec - , LBT/MODS1 + MODS2 - , HST/ACS - , HST/WFC3 - .Attached Files
Published - Humphreys_2017_ApJ_848_86.pdf
Submitted - 1709.01528.pdf
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Additional details
- Eprint ID
- 82432
- Resolver ID
- CaltechAUTHORS:20171017-144643437
- AST-1109394
- NSF
- AST-9987045
- NSF
- Ohio Board of Regents
- Ohio State University
- Created
-
2017-10-17Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)