RXTE observations of the X-ray transient XTE J1859+226

We present results of RXTE observations of XTE J1859+226. a transient and p robable microquasar discovered in October, 1999. The light curve approximat ely followed a fast-rise exponential-decay, with a peak flux of about 1.2 C rab (2-10 keV). The source is at a galactic latitude of +8.5 degrees. which makes it difficult to estimate distance and luminosity precisely. QPOs wer e detected in the 150-200 Hz and 0.5-10 Hz ranges, The high frequency QPOs and the results of spectral fitting can be used to loosely constrain the ce ntral object mass.