Abstract:
We report the results of the transit timing variation (TTV) analysis of the extra-solar planet Qatar1b using thirty eight light curves. Our analysis combines thirty five previously available transit light curves
with three new transits observed by us between June 2016 and September 2016 using the 2-m Himalayan
Chandra Telescope (HCT) at the Indian Astronomical Observatory (Hanle, India). From these transit data, the
physical and orbital parameters of the Qatar-1 system are determined. In addition to this, the ephemeris for
the orbital period and mid-transit time are refined to investigate the possible TTV. We find that the null-TTV
model provides the better fit to the (O-C) data. This indicates that there is no evidence for TTVs to confirm
the presence of additional planets in the Qatar-1 system. The use of the 3.6-m Devasthal Optical Telescope
(DOT) operated by the Aryabhatta Research Institute of Observational Sciences (ARIES, Nainital, India) could
improve the photometric precision to examine the signature of TTVs in this system with a greater accuracy than
in the present work.
