Journal ArticleSN 2019zrk, a bright SN 2009ip analog with a precursorFransson, Claes; Sollerman, Jesper; Strotjohann, Nora L.; Yang, Sheng; Schulze, Steve; Barbarino, Cristina; Kool, Erik C.; Ofek, Eran O.; Crellin-Quick, Arien; De, Kishalay; Drake, Andrew J.; Fremling, Christoffer; Gal-Yam, Avishay; Ho, Anna Y.; Kasliwal, Mansi M.We present photometric and spectroscopic observations of the Type IIn supernova SN 2019zrk (also known as ZTF 20aacbyec). The SN shows a > 100 day precursor, with a slow rise, followed by a rapid rise to M  ≈ −19.2 in the r and g bands. The post-peak light-curve decline is well fit with an exponential decay with a timescale of ∼39 days, but it shows prominent undulations, with an amplitude of ∼1 mag. Both the light curve and spectra are dominated by an interaction with a dense circumstellar medium (CSM), probably from previous mass ejections. The spectra evolve from a scattering-dominated Type IIn spectrum to a spectrum with strong P-Cygni absorptions. The expansion velocity is high, ∼16 000 km s −1 , even in the last spectra. The last spectrum ∼110 days after the main eruption reveals no evidence for advanced nucleosynthesis. From analysis of the spectra and light curves, we estimate the mass-loss rate to be ∼4 × 10 −2   M ⊙ yr −1 for a CSM velocity of 100 km s −1 , and a CSM mass of 1  M ⊙ . We find strong similarities for both the precursor, general light curve, and spectral evolution with SN 2009ip and similar SNe, although SN 2019zrk displays a brighter peak magnitude. Different scenarios for the nature of the 09ip-class of SNe, based on pulsational pair instability eruptions, wave heating, and mergers, are discussed.2022-10-0110423984Astronomy & Astrophysics666A790004-6361https://doi.org/10.1051/0004-6361/2022434522034437National Science Foundation