Situated adjacent to the picturesque hill town of Nainital, ARIES (an acronym of Aryabhatta Research Institute of Observational Sciences) is one of the leading research Institutes which specializes in observational Astronomy & Astrophysics and Atmospheric Sciences. The main research interests of Astronomy & Astrophysics division are in solar, planetary, stellar, galactic and extra-galactic astronomy including stellar variabilities, X-ray binaries, star clusters, nearby galaxies, quasars, and inherently transient events like supernovae and highly energetic Gamma Ray Bursts. Research focus in Atmospheric Sciences division is mainly in the lower part of the atmosphere and covers the studies on aerosols and trace gases. Moreover, to strengthen the scientific contribution, the Institute has extended its horizon to theoretical and numerical studies in Relativistic Astrophysics. The unique position of ARIES (79° East), places it at almost in the middle of 180° wide longitude band, between Canary Island (20° West) and Eastern Australia (157° East), and therefore complements observations which might not be possible from either of these two places. ARIES has made unique contribution from time to time. To quote examples from the past the first successful Indian optical observations of the afterglow of gamma-ray burst was carried out from ARIES on January 23, 1999, a few micro-lensing events and quasar variability, new ring systems around Saturn, Uranus, and Neptune were also discovered.
The Institute hosts four telescopes of apertures 104-cm, 130-cm, 3.6-mDOT and 4-m ILMT. There is a 15-cm telescopes dedicated for solar observations. The 104-cm optical telescope is being used as a main observing facility by the ARIES scientists since 1972. It is equipped with 2k x 2k, and 1k x 1k liquid N cooled CCD cameras, fast photometer, spectrophotometer, and standard astronomical 2 filters. The telescope uses a SBIG ST-4 camera for auto-guiding through an auxiliary 20-cm telescope.
In order to carry out observations in the frontier areas of astronomy, the Institute has installed 130-cm, 360-cm and 400-cm optical telescopes at a site called 'Devasthal' at a distance of ~ 60-Km from ARIES, which has the advantages of having dark skies and excellent observing conditions. The Scientists from the Solar group of ARIES are also participating in the national projects like space coronagraph and National Large Solar Telescope (NLST). There are different instruments for observation of physical and optical properties of aerosols and trace gas. An 84-cm micro-pulse LIDAR system for high altitude studies of aerosols and a ST Radar (Stratosphere Troposphere Radar) to measure winds speed up to an altitude of around 20 km is also operational at Nainital.