and \[tab-nucore-fast\]) due to a gap in the baryon energy spectrum. At $T \ll T_{\rm c}$, the reduction is exponentially strong. For instance, the powerful direct Urca process can be formally open in the inner core, but completely suppressed by a strong superfluidity of neutrons of protons. In addition, when $T$ falls below $T_{\rm c}$, superfluidity initiates a specific neutrino emission due to Cooper pairing of baryons [@frs76] which enhances neutrino cooling. This mechanism can enhance the neutrino luminosity of the star by a factor of $\la 30-100$ over the modified Urca level [@pageetal04; @gusakovetal04]. Superfluidity affects also neutron star heat capacity [@yls99] and thermal conductivity [@bhy01; @sy07] but these effects are less strong.

OBSERVATIONS
============

   Number  Source                        $t$ \[kyr\]   $T_{\rm s}^\infty$ \[MK\]   Confid.      Model    Ref. 
  -------- ---------------------------- ------------- --------------------------- ---------- ----------- ---------------------
     1     PSR B0531+21 (Crab)                1                 $<$2.0              99.8%        BB      [@weisskopf04]
     2     PSR J0205+6449 (in 3C 58)      0.82–5.4              $<$1.02             99.8%        BB      [@slane04a]
     3     PSR J1119–6127                $\sim 1.6$          $\approx$ 1.2            –          mHA     [@zavlin07]
     4     RX J0822–4300 (in Pup A)          2–5                1.6–1.9              90%         HA      [@ztp99]
     5     PSR J1357–6429                $\sim 7.3$        $\approx 0.766 $           –          mHA     [@zavlin07a]
     6     RX J0007.0+7303 (in CTA 1)       10–30              $<$ 0.66               –          BB      [@halpernetal04]
     7     PSR B0833–45 