Photometric and spectroscopic evolution of the interacting transient AT 2016jbu(Gaia16cfr)
Sollerman, J.; Reichart, D. E.; Harrison, D. L.; Hanlon, L.; Soszyński, I.; Udalski, A.; Pietrukowicz, P.; Skowron, J.; Poleski, R.; Kozłowski, S.; Gromadzki, M.; Ulaczyk, K.; Galbany, L.; Inserra, C.; Brown, P. J.; Gutiérrez, C. P.; Howell, D. A.; Johansson, J.; Smartt, S. J.; Rau, A.; Hodgkin, S. T.; van Leeuwen, M.; Delgado, A.; Chen, T. -W.; Kankare, E.; Young, D. R.; Maguire, K.; Kotak, R.; Dong, Subo; Benetti, S.; Shahbandeh, M.; Shappee, B. J.; Morrell, N.; Stritzinger, M. D.; Kuncarayakti, H.; Fraser, M.; McCully, C.; Pignata, G.; Nicholl, M.; Hiramatsu, D.; Holoien, T. W. -S.; van Soelen, B.; Tartaglia, L.; Elias-Rosa, N.; Hosseinzadeh, G.; Eldridge, J. J.; Dennefeld, M.; Prieto, J. L.; Blondin, S.; Stevance, H. F.; Schweyer, T.; Cartier, R.; Hsiao, E.; Bento, J.; Nyholm, A.; Monard, B.; Müller-Bravo, T. E.; Martin-Carrillo, A.; Bose, S.; Pastorello, A.; Brennan, S. J.; Chen, Ping; Wyrzykowski, L.; Meintjes, P.; Sand, D.; Tucker, B. E.; Abbot, H.; Szymański, M.; O'Neill, D.; Callis, E.; Duffy, P.
Ireland, Sweden, Italy, Finland, New Zealand, Germany, United States, Chile, France, China, Spain, South Africa, United Kingdom, Australia, Poland, Denmark
Abstract
We present the results from a high-cadence, multiwavelength observation campaign of AT 2016jbu (aka Gaia16cfr), an interacting transient. This data set complements the current literature by adding higher cadence as well as extended coverage of the light-curve evolution and late-time spectroscopic evolution. Photometric coverage reveals that AT 2016jbu underwent significant photometric variability followed by two luminous events, the latter of which reached an absolute magnitude of MV ~ -18.5 mag. This is similar to the transient SN 2009ip whose nature is still debated. Spectra are dominated by narrow emission lines and show a blue continuum during the peak of the second event. AT 2016jbu shows signatures of a complex, non-homogeneous circumstellar material (CSM). We see slowly evolving asymmetric hydrogen line profiles, with velocities of 500 km s-1 seen in narrow emission features from a slow-moving CSM, and up to 10 000 km s-1 seen in broad absorption from some high-velocity material. Late-time spectra (~+1 yr) show a lack of forbidden emission lines expected from a core-collapse supernova and are dominated by strong emission from H, He I, and Ca II. Strong asymmetric emission features, a bumpy light curve, and continually evolving spectra suggest an inhibit nebular phase. We compare the evolution of H α among SN 2009ip-like transients and find possible evidence for orientation angle effects. The light-curve evolution of AT 2016jbu suggests similar, but not identical, circumstellar environments to other SN 2009ip-like transients.