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The Type Ic SN 1990B in NGC 4568

Clocchiatti, Alejandro and Suntzeff, Nicholas B. and Phillips, Mark M. and FIlippenko, Alexei V. and Turatto, Massimo and Benetti, Stefano and Cappellaro, Enrico and Aviles, Roberto and Covarrubias, Ricardo and DeGioia-Eastwood, K. and Dickinson, Mark and Gouiffes, Christian and Guhathakurta, Puragra and Hamuy, Mario and Heathcoate, Steve R. and Leibundgut, Bruno and Matheson, Thomas and Navarrete, Mauricio and Perez, M. and Phillips, Andrew and Piemonte, Antonello and Ruiz, María T. and Shields, Joseph C. and Smith, Chris and Spinrad, Hyron and Struch, Conrad R. and Tyson, J. Anthony and Wells, Lisa (2001) The Type Ic SN 1990B in NGC 4568. Astrophysical Journal, 553 (2). pp. 886-896. ISSN 1538-4357


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Publisher’s or external URL: http://dx.doi.org/10.1086/320940


We present a study of the Type Ic supernova (SN) 1990B that includes most of the observations obtained from around the world. The combined data set comprises 84 BV(RI)(c) photometric points spanning approximately 360 days after maximum light and 14 spectra from 5 up to similar to 150 days after maximum light. In contrast to other Type Ic SNe, SN 1990B did not display a weak but distinct He I lambda 5876 line indicating that its He content was smaller or that the He layers were rather effectively shielded from the radioactive matter in the ejecta. The behavior of the Na I D line, however, suggests that He I lambda 5876 was blended with it. SN 1990B appeared on a sharply varying background that complicates the usual techniques of digital photometry. In order to do unbiased photometry, we modeled and subtracted the background of each image with the SN using images of NGC 4568 taken ~2500 days after the explosion, when SN 1990B had faded beyond detection. We compare the performance of standard point-spread function fitting photometry of the SN in the images with and without the background of the parent galaxy and find the results to differ systematically at late times. The photometry done on the images with the background light of NGC 4568 subtracted shows the light curves of SN 1990B to be of the slow Type Ic variety, with a slope steeper than that of the Type Ib SN 1983N or the Type II transition (Type IIb) SN 1993J but slower than that of the Type Ic SN 1994I. We estimate the reddening by foreground matter in the Galaxy and NGC 4568 and compute BV(RI)(c) light curves spanning similar to 110 days after maximum light.

Item Type: Article
ID number or DOI: 10.1086/320940
Keywords: 1994i; emission; helium; ib supernovae; Light; m51; m81; sn-1993j; standard stars; supernovae : general; supernovae : individual (SN 1990B); ubvri photometry
Subjects: Q Science > QB Astronomy
NAU Depositing Author Academic Status: Faculty/Staff
Department/Unit: College of Engineering, Forestry, and Natural Science > Physics and Astronomy
Date Deposited: 25 Sep 2015 18:37
URI: http://openknowledge.nau.edu/id/eprint/100

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