The Absolute K Magnitude and the Distance of OH/IR Stars

The absolute K magnitudes and the distances of some OH/IR stars are calculated and discussed in this paper.It is found that the absolute K magnitude is almost constant for the OH/IR stars with the bright apparent K magnitude (K<4.0), but the absolute K magnitude is dispersed and dimmer for the OH/IR stars with K> 4.0.The dimmer and dispersed absolute K magnitudes may be caused by the thicker circumstaller dust shells of these stars.The relation between the apparent K magnitude and the distance for the OH/IR stars with K < 4.0 is also given, so that the distances of the OH/IR stars with K< 4.0 can be estimated form the apparent K magnitude, and the problem of the correction of interstallar reddening of these stars is also solved.