Coin shaped yellowish object in West Bengal, India.The setting: I and my sister was standing on the rooftop(it is the tallest structure nearby) when I was showing her various stars. It was 23:00 Indian standard time, date 20/09/2012 and most of the city was in slumber(as usual. It is a very small town of the indian state west bengal).The event: Sky was perfectly clear(no cloud anywhere) full of stars and no moon, as usual there was little city light. It was then I saw an circular, flattened object, size of a small coin(5 cent coin), colored yellowish(looked like if it was made from cheap plastic), flew from west to east through a perfect perpendicular(with earth) and in straight line. It was not emitting any light(like aircrafts do) nor It left a trail or haze. It flew faster than a bird but much slower than a meteor(again there was no trail). There was no sound.My background info: Physician with MBBS degree(I don't drink, nor use any drug which may cause any impairment of perceptions).My sister: Perusing pre-med.