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Optical observations of type IIP supernova 2004dj: Evidence for the asymmetry of $^{56}$Ni ejecta

N. N. Chugai·S. N. Fabrika·O. N. Sholukhova·V. P. Goranskij·P. K. Abolmasov·V. V. Vlasyuk
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Abstract

The photometric and spectroscopic observations of nearby type IIP supernova 2004dj are presented. The $^{56}$Ni mass estimated from the light curve is $\approx0.02 M_{\odot}$. This estimate is found to be consistent with the H$α$ luminosity. SN2004dj reveals a strong asymmetry of the H$α$ emission line at the nebular epoch with the shift of the maximum of -1600 km s$^{-1}$. A similar asymmetric component is detected in H$β$, [O I] and [Ca II] lines. The line asymmetry is interpreted as a result of the asymmetry of $^{56}$Ni ejecta. The H$α$ profile and its evolution are reproduced in the model of the asymmetric bipolar $^{56}$Ni and spherical hydrogen distributions. The mass of the front $^{56}$Ni jet is comparable to the central component and twice as larger compared to the rear $^{56}$Ni jet. We note that the asymmetric bipolar structure of of $^{56}$Ni ejecta is revealed also by SN1999em, another type IIP supernova.

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N. N. Chugai, S. N. Fabrika, O. N. Sholukhova, V. P. Goranskij, P. K. Abolmasov, V. V. Vlasyuk. 2005-07-29. Optical observations of type IIP supernova 2004dj: Evidence for the asymmetry of $^{56}$Ni ejecta. https://doi.org/10.1134/1.2138766

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