Speaker
Description
The European Astronomical Society of Small Telescopes (EASST) is a non-profit organization dedicated to enabling high-quality astronomical research with small and medium aperture telescopes. Within this framework, the Black Hole Target and Observation Manager (BHTOM) has been developed as a robust, web-based observational coordination system designed to support both professional and amateur astronomers. BHTOM enables systematic, long-term, rapid-cadence photometric monitoring of diverse astrophysical targets, including gravitational microlensing events, variable stars, transients, quasars, exoplanets, and Solar system objects.
The BHTOM network currently integrates data from nearly 130 telescopes worldwide, many of which are operated by skilled amateur observers and professional astronomers. The platform provides tools for automated scheduling, data reduction, and centralized data sharing, thereby streamlining the production of science-ready photometric measurements. This infrastructure facilitates large-scale, distributed observing campaigns and significantly enhances the scientific return achievable with small-aperture instrumentation.
One of the scientific focuses of BHTOM is gravitational microlensing, a technique uniquely sensitive to compact, non-luminous objects such as stellar-mass black holes, neutron stars, and free-floating planets. Microlensing observations offer insights into the Galaxy’s dark or otherwise invisible population, including potential primordial black holes and candidates for dark matter. The Gaia mission, launched by ESA in 2013, has played a key role in identifying microlensing events, and forthcoming data releases (DR4 and DR5) are expected to increase the number of events substantially.
This presentation provides an overview of the BHTOM system and the crucial contribution of small telescopes, including those operated in Lithuania at the Moletai Astronomical Observatory, to the follow-up of Gaia-discovered microlensing events, including Gaia16aye, Gaia18cbf, Gaia19bld, Gaia19dke, AT2021uey, and Gaia20fnr. Coordinated observations from the BHTOM network have enabled precise characterization of lens masses and distances, demonstrating that collective efforts of small-telescope observers can deliver high-impact scientific results. The talk aims to highlight these achievements and encourage further participation from the global astronomy community. E.S., M.M., J.Z., E.P., V.C., and U.J. acknowledge funding from the Research Council of Lithuania (LMTLT, grant No. S-LL-24-1).