Aryabhatta Research Institute of Observational Sciences (ARIES) is one of the leading research Institutes which specializes in observational Astronomy and Astrophysics and Atmospheric Sciences. The main research interests of Astronomy and 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 its scientific contribution, the Institute has extended its horizon to theoretical and numerical studies in Relativistic Astrophysics. The Scientists from the Solar group of ARIES also participate in national projects like space coronagraph and National Large Solar Telescope (NLST). The unique position of ARIES (79ø East), places it at almost in the middle of 180ø wide longitude band, between Canary Island (20ø West) and Eastern Australia (157ø East), and therefore complements observations which might not be possible from either of these two places.

The name of the post of Chief Astronomer was changed to Director in September 1958. The Director was bestowed full power of a Head of the Institution in 1965. Upon transfer from the state of Uttar Pradesh to Uttaranchal on 09th November 2000, this organization was named `State Observatory` (SO). On March 22nd 2004, SO was converted to Aryabhatta Research Institute of Observational Sciences (ARIES), an autonomous institution under the Department of Science & Technology (DST), Government of India.

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 being setup. The Institute hosts two telescopes of apertures 56-cm and 104-cm. There are two 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 is setting up 130-cm and 360-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 130-cm telescope is expected to be operational by the end of 2010, and the 360-cm telescope will be operational by 2012.