SN 2009ip is an LBV Outburst

We obtained medium-resolution optical spectra of SN2009ip in NGC 7259 (CBET #1928) with the Magellan Echellete Spectrograph mounted on the Magellan/Clay 6.5-m telescope on 2009 September 1.24 UT. The spectra exhibit narrow (FWHM ~ 550 km/s) hydrogen Balmer emission lines centered at the systemic velocity of NGC 7259. These properties, along with a peak optical absolute magnitude of about -13.7 mag, previous variability at the same position, and a potential progenitor with M~-10 mag (ATEL #2183) indicate that SN2009ip is a luminous blue variable (LBV) outburst, similar to previous SN impostors such as SN1997bs (Van Dyk et al.