the conventional models is that strange stars are almost bare, especially in the polar cap region, if they are formed directly from supernova explosions. Such bare polar cap strange stars (BPCSSs), can also well act as radio pulsars[@xq98; @xqz99]. In Sect.2, we will discuss that phase transition from nuclear matter to SQM may be an important mechanism to retain a successful supernova explosion, and the strange stars, if born as the products of the explosions, are very likely to have [*very*]{} thin crusts ($\sim 10^{-15}M_\odot$) and bare polar caps almost throughout their lifetimes. The electrical and thermal properties of BPCSSs are discussed in Sect.3, focusing on some distinguishing properties as compared with neutron stars. In Sect.4, we test this BPCSS idea with the present available radio and high energy emission data of pulsars, and point out the strong and weak aspects of the idea. Finally we will propose some possible approaches to distinguish BPCSSs from neutron stars in Sect.5, and summarize the conclusions in Sect.6.

Newborn strange stars
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Supernova explosions: neutron stars or strange stars?
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The theory of stellar structure and evolution has been proved a great success in astrophysics. However, some challenges still exist in understanding a 