Institute of Astronomy

Variable Universe

Variability of brightness of stars and other objects is one of the most important tools in studying the Universe. Studies of variable objects provide input to a wide range of fields of astrophysics, from understanding the internal composition of the stars and detection of extrasolar planets, to revealing the structure of galaxies and detecting invisible matter. In the IoA we are involved in various photometric surveys, including SDSS, OGLE and Gaia.

Variability Tree

RR Lyrae stars

These well known distance indicators are perfect tools for disentangling the internal structure of the Milky Way and tracing tidally disrupted galaxies in the halo of our Galaxy.

Microlensing events

Microlensing events are unique brightening phenomena observed in one in a million of stars towards the Galactic Centre caused by the effect of gravitational lensing by an object passing in front of a background star. Microlensing depends on the mass of the object therefore can be used in detecting dark matter in compact objects or extra-solar planets. IoA members are involved in the main microlensing survey, Optical Gravitational Lensing Experiment (OGLE) which continuously observes the Galactic Centre and finds almost a thousand microlensing events every year.

Supernovae and other transients with Gaia satellite

Members of the IoA are preparing the photometry processing for the cornerstone ESA mission, Gaia. Shortly after launch of the satellite in 2013 the IoA will be also analysing the incoming data from the satellite in order to detect any kind of astrophysical anomalies or appearances of a new interesting objects on the sky. This will include numerous supernovae, novae, optical counter-parts to gamma-ray bursts, microlensing events and other interesting transients. More can be found on Gaia Science Alerts Working Group website: