2008/11/30 by S. Blondin, J. L. Prieto, F. Patat +7 · 4 citations
Mathematics · Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Gamma-ray bursts and supernovae #Geology #Mathematics #Physics #Pulsars and Gravitational Waves Research #Spectral line #Supernova #Type (biology) #Variable (mathematics) #astro-ph
paper · pdf · doi:10.1088/0004-637x/693/1/207
published as Astrophys.J.693:207-215,2009 · 10 pages, 5 figures (original paper); 6 pages, 6 figures (Erratum). ApJ, accepted
openalex publication_date 2009/03/01 · openalex created_date 2016/06/24 · arxiv created 2017/07/10 · arxiv updated 2017/07/11 · openalex updated_date 2026/08/05
Recent high-resolution spectra of the Type Ia supernova SN 2006X have revealed the presence of time-variable and blueshifted Na i D features, interpreted by Patat et al. as originating in circumstellar material within the progenitor system. The variation seen in SN 2006X induces relatively large changes in the total Na i D equivalent width (ΔEW ∼ 0.5 Å in just over two weeks) that would be detectable at lower resolutions. We have used a large data set comprising 2400 low-resolution spectra of 450 Type Ia supernovae (SNe Ia) obtained by the CfA Supernova Program to search for variable Na i D features. Out of the 31 SNe Ia (including SN 2006X) in which we could have detected similar EW variations, only one other (SN 1999cl) shows variable Na i D features, with an even larger change over a similar ∼10 day timescale (ΔEW = 1.66 ± 0.21 Å). Interestingly, both SN 1999cl and SN 2006X are the two most highly reddened objects in our sample, raising the possibility that the variability is connected to dusty environments.