The
striking
case of RX J1856.5-3754
n
500 ks DDT Chandra exposure
(i) RX J1856.5-3754 has a
featureless
X-ray continuum
(ii) better fit with a simple bb than with more
sophisticated atmospheric models (Burwitz et al 2001,
Drake et al 2002
, Burwitz et al, 2002)