EDP Sciences
Free access
Volume 429, Number 2, January II 2005
Page(s) 667 - 676
Section Stellar structure and evolution
DOI http://dx.doi.org/10.1051/0004-6361:20041687

A&A 429, 667-676 (2005)
DOI: 10.1051/0004-6361:20041687

Type Ia supernova SN 2003du: Optical observations

G. C. Anupama1, D. K. Sahu1, 2 and J. Jose1, 2

1  Indian Institute of Astrophysics, II Block Koramangala, Bangalore 560 034, India
    e-mail: gca@iiap.res.in
2  Center for Research and Education in Science & Technology, Hosakote
    e-mail: dks@crest.ernet.in

(Received 19 July 2004 / Accepted 15 September 2004 )

$\it UBVRI$ photometry and optical spectra of type Ia supernova SN 2003du obtained at the Indian Astronomical Observatory for nearly a year since discovery are presented.

The apparent magnitude at maximum was  $B=13.53\pm 0.02$ mag, and the colour  $(B-V)=-0.08\pm 0.03$ mag. The luminosity decline rate, $\Delta m_{15}(B)=1.04\pm 0.04$ mag indicates an absolute  B magnitude at maximum of  $M_B^{{\rm max}}=-19.34\pm 0.3$ mag and the distance modulus to the parent galaxy as  $\mu=32.89\pm 0.4$. The light curve shapes are similar, though not identical, to those of SNe 1998bu and 1990N, both of which had luminosity decline rates similar to that of SN 2003du and occurred in spiral galaxies. The peak bolometric luminosity indicates that ~ $0.9~{{M}}_\odot$ mass of  56Ni was ejected by the supernova. The spectral evolution and the evolution of the Si II and Ca II absorption velocities closely follows that of SN 1998bu, and in general, is within the scatter of the velocities observed in normal type Ia supernovae.

The spectroscopic and photometric behaviour of SN 2003du is quite typical for SNe Ia in spirals.

A high velocity absorption component in the Ca II (H and K) and IR-triplet features, with absorption velocities of ~ $20\,000$ km s -1 and ~ $22\,000$ km s -1 respectively, is detected in the pre-maximum spectra of days  -11 and  -7.

Key words: stars: supernovae: general -- stars: supernovae: individual: SN2003du

SIMBAD Objects

© ESO 2004