| Authors | Botticella, M. T.; Trundle, C.; Pastorello, A.; Rodney, S.; Rest, A.; Gezari, S.; Smartt, S. J.; Narayan, G.; Huber, M. E.; Tonry, J. L.; Young, D.; Smith, K.; Bresolin, F.; Valenti, S.; Kotak, R.; Mattila, S.; Kankare, E.; Wood-Vasey, W. M.; Riess, A.; Neill, J. D.; Forster, K.; Martin, D. C.; Stubbs, C. W.; Burgett, W. S.; Chambers, K. C.; Dombeck, T.; Flewelling, H.; Grav, T.; Heasley, J. N.; Hodapp, K. W.; Kaiser, N.; Kudritzki, R.; Luppino, G.; Lupton, R. H.; Magnier, E. A.; Monet, D. G.; Morgan, J. S.; Onaka, P. M.; Price, P. A.; Rhoads, P. H.; Siegmund, W. A.; Sweeney, W. E.; Wainscoat, R. J.; Waters, C.; Waterson, M. F.; Wynn-Williams, C. G. |
| Abstract | We present photometric and spectroscopic observations of a luminous Type IIP Supernova (SN) 2009kf discovered by the Pan-STARRS 1 (PS1) survey and also detected by the Galaxy Evolution Explorer. The SN shows a plateau in its optical and bolometric light curves, lasting approximately 70 days in the rest frame, with an absolute magnitude of M V = -18.4 mag. The P-Cygni profiles of hydrogen indicate expansion velocities of 9000 km s-1 at 61 days after discovery which is extremely high for a Type IIP SN. SN 2009kf is also remarkably bright in the near-ultraviolet (NUV) and shows a slow evolution 10-20 days after optical discovery. The NUV and optical luminosity at these epochs can be modeled with a blackbody with a hot effective temperature (T ~ 16,000 K) and a large radius (R ~ 1 × 1015 cm). The bright bolometric and NUV luminosity, the light curve peak and plateau duration, the high velocities, and temperatures suggest that 2009kf is a Type IIP SN powered by a larger than normal explosion energy. Recently discovered high-z SNe (0.7 < z < 2.3) have been assumed to be IIn SNe, with the bright UV luminosities due to the interaction of SN ejecta with a dense circumstellar medium. UV-bright SNe similar to SN 2009kf could also account for these high-z events, and its absolute magnitude M NUV = -21.5 ± 0.5 mag suggests such SNe could be discovered out to z ~ 2.5 in the PS1 survey. |
