Optical-NIR SED and spectroscopy of ROTSE3 J115649.1+542726

ROTSE3 J115649.1+542726 (Yuan et al. 2008; ATel #1515) is a blue optical/UV transient claimed as an AGN, and later proposed by Gezari & Halpern 2008 (ATel #1524) as a tidal disruption (TDF) event at z~1. Here we report on extensive follow-up coverage and present evidence that does not support the z~1 TDF and AGN hypotheses. Instead, we suggest a plausible hypothesis is that ROTSE3 J115649.1+542726 is a peculiar, bright SN at z~0.07; other possibilities, such as a transient at z=0 or a TDF at z~0.07 are not excluded.