Is PSR J1957+5033 the coldest neutron starquestionMark

We propose XMMNewton observations of 840 kyr old radioquiet gammaray pulsarJ1957+5033. Its short Chandra observations revealed the presence of a very softXray emission in the 0.10.3 keV range. This suggests that the pulsar Xrayspectrum can have a soft thermal component from the NS surface with thetemperature of 2740 eV, as is expected for the NS at the photon cooling stage.PSR J1957+5033 can be the coldest isolated neutron star at the age of 1 Myr,which is important for comparison with cooling scenarios of these stars. Werequest for 80 ks observations to confirm this as it is not possible withChandra due to calibration uncertainties at low energies. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]