We have been monitoring Supernova ( SN ) 1987A with Chandra X-Ray Observatory since 1999 .
We present a review of previous results from our Chandra observations , and some preliminary results from new Chandra data obtained in 2006 and 2007 .
High resolution imaging and spectroscopic studies of SN 1987A with Chandra reveal that X-ray emission of SN 1987A originates from the hot gas heated by interaction of the blast wave with the ring-like dense circumstellar medium ( CSM ) that was produced by the massive progenitor ’ s equatorial stellar winds before the SN explosion .
The blast wave is now sweeping through dense CSM all around the inner ring , and thus SN 1987A is rapidly brightening in soft X-rays .
At the age of 20 yr ( as of 2007 January ) , X-ray luminosity of SN 1987A is L _ { X } \sim 2.4 \times 10 ^ { 36 } ergs s ^ { -1 } in the 0.5 - 10 keV band .
X-ray emission is described by two-component plane shock model with electron temperatures of kT \sim 0.3 and 2 keV .
As the shock front interacts with dense CSM all around the inner ring , the X-ray remnant is now expanding at a much slower rate of v \sim 1400 km s ^ { -1 } than it was until 2004 ( v \sim 6000 km s ^ { -1 } ) .