Early-time spectroscopic observations of SN 1998aq in NGC 3982

Abstract

Medium resolution spectroscopic observations of SN 1998aq made in April-May, 1998, are presented. We confirm its Type Ia classification based on the prominent Si II 6355 A line and other features similar to SNe Ia. No significant sign of hydrogen Balmer-alpha line was seen in high-resolution spectra taken at 8 days before maximum. Preliminary estimate of reddening and distance modulus, based on the correlation between the line depth ratio of two Si II features around 6000 A and BVRI light curves of Type Ia SNe, is presented. Moreover, H-alpha emission from the core of the Seyfert 2 type host galaxy NGC 3982 has also been detected.