The striking case of RX J1856.5-3754
Optical excess of ~6 over the
Rayleigh-Jeans tail of the X-ray
best fitting bb (Walter
& Lattimer, 2002)
No X-ray pulsations: upper limit on the pulsed
fraction £1% (Burwitz et al., 2003)
previous d ~120-140 pc (Kaplan et al, 2001; Walter &
Lattimer, 2002)
Þ revised d
~175 pc (Kaplan et al., 2003, Korea meeting)
Þ radiation radius of only 7-8 km!
€
Two-T model: x-ray
= caps; optical = star surface (Pons et al. 2002; Walter & Lattimer, 2002)
€
Is it the first quark/strange star discovered?
(Drake et al, 2002; Xu, 2002)
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Phase transition to a solid surface (B>few
x1013 G) (Turolla et al. 2003)
(Pons et al, 2002; Walter &
Lattimer, 2002 )