Top-left: NGC 4490−2011OT1 in its host galaxy. The R-band image was obtained on 2012 March 24 with the 2.2 m telescope of the Calar Alto Observatory, equipped with CAFOS. Top-right: NGC 3437−2011OT1 and its host galaxy. The R-band image was obtained on 2011 January 15 with the 2.2 m telescope of the Calar Alto Observatory, with CAFOS. A blow-up showing the transient is in the upper-left inset. Middle-left: UGC 12307−2013OT1 and its host galaxy. The R-band image was obtained on 2013 October 11 with the 3.58 m Telescopio Nazionale Galileo, equipped with LRS. A blow-up with the transient is shown in the upper-left inset. Middle-right: SN 1997bs in NGC 3627. The R-band image was obtained on 1997 April 27 with the 0.91 m Dutch Telescope at ESO – La Silla. Bottom-left: M 101−2015OT1 in the outskirts of its host galaxy. The Sloan-r band image was obtained on 2015 February 18 with the 1.82 m Asiago Copernico Telescope plus AFOSC. Bottom-right: SNhunt248 in NGC 5806. The AFOSC image in the Sloan-r band was obtained on 2014 July 18.