The Progenitor of Supernova 1993J Revisited

December 2002 • 2002PASP..114.1322V

Authors • Van Dyk, Schuyler D. • Garnavich, Peter M. • Filippenko, Alexei V. • Höflich, Peter • Kirshner, Robert P. • Kurucz, Robert L. • Challis, Peter

Abstract • From Hubble Space Telescope images with 0.05" resolution, we identify four stars brighter than V=25 mag within 2.5" of SN 1993J in M81, which contaminated previous ground-based brightness estimates for the supernova progenitor. Correcting for the contamination, we find that the energy distribution of the progenitor is consistent with that of an early K-type supergiant star with M_V~-7.0+/-0.4 mag and an initial mass of 13-22 M_solar. The brightnesses of the nearby stars are sufficient to account for the excess blue light seen from the ground in preexplosion observations. Therefore, the SN 1993J progenitor did not necessarily have a blue companion, although by 2001, fainter blue stars are seen in close proximity to the supernova. These observations do not strongly limit the mass of a hypothetical companion. A blue dwarf star with a mass up to 30 M_solar could have been orbiting the progenitor without being detected in the ground-based images. Explosion models and observations show that SN 1993J progenitor had a helium-rich envelope. To test whether the helium abundance could influence the energy distribution of the progenitor, we calculated model supergiant atmospheres with a range of plausible helium abundances. The models show that the presupernova colors are not strongly affected by the helium abundance longward of 4000 Å, and abundances ranging between solar and 90% helium (by number) are all consistent with the observations. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained in part from the data archive of the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

Links

• PREPRINT http://arxiv.org/abs/astro-ph/0208382
• NED https://ned.ipac.caltech.edu/uri/NED::InRefcode/2002PASP..114.1322V
• ELECTR https://iopscience.iop.org/article/10.1086/344382
• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2002PASP..114.1322V
• PDF https://iopscience.iop.org/article/10.1086/344382/pdf
• DATA https://archive.stsci.edu/mastbibref.php?bibcode=2002PASP..114.1322V
• DATA https://hst.esac.esa.int/ehst/#/pages/search;bibcode=2002PASP..114.1322V
• SPIRES http://inspirehep.net/search?p=find+eprint+astro-ph/0208382