Analysis of WFCAM images of M33 galaxy

In this study، 1200 images and catalogues of M33 spiral galaxy taken by WFCAM camera at UKIRT telescope in J، H and K bands. Cross correlation methods were employed to identify stars in overlapping regions from among images taken in different dates. Careful astrometric and photometric analysis was made to calibrate stellar positions and magnitudes using their 2MASS near infra red survey. The final catalogue consisted of 445303 stars and covered more than 0. 75 square degrees of sky centered on M33 core، which included the bulge and spiral arms. This is the biggest catalogue ever made from a nearby spiral galaxy in near infrared. A color magnitude diagram in near infrared was plotted، which shows a bunch of very red stars that extended to J-K = 4.