Is Calvera riding against the Magnificent Seven

Recent Chandra, Swift and Gemini observations of 1RXS J141256.0+792204 suggestthat it is a new Isolated Neutron Star (INS). However, the INS nature of thissource, dubbed Calvera, relies only on its large Xraytooptical flux ratio. Anidentification with an Xray dim INS or a magnetar seems unlikely while thatwith a Compact Central Object or an old solitary mspulsar appears moreplausible. Here we propose a 28 ks observation to obtain the first highqualityXray spectrum of Calvera and to perform an accurate timing analysis. The newXray data will clarify whether Calvera is an ordinary member of one of thealready known INS classes or, more intriguing, if it is one of the long soughtmissing links required to unify the different INS classes in a common scenario. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]