Monthly Meeting June

Precision Metrology of the Sky: Advances and Problems of VLBI Astrometry

The use of Very Long Baseline Interferometry (VLBI) technique revolutionizes modern astrometry. It surpasses Gaia’s positional accuracy and allows conducting distance (parallax) measurements in the galactic plane far beyond the reach of optical telescopes. In this talk I will describe the method and report on some recent developments at the Warkworth Radio Astronomical Observatory in the field of radio (VLBI) astrometry. We will discuss problems of positional measurements in radio astronomy, talk about effects of radio source structure on determination of its precise position on the sky, about the perspectives of mapping spiral arms beyond the Galactic Centre with the use of methanol maser emission sources, learn about the “Gaia Sausage” as well as of a new class of pulsars based on rotating white dwarfs (rather than neutron stars).

Professor Sergei Gulyaev is the founder and director of AUT’s Institute for Radio Astronomy and Space Research (IRASR). Under his direction, the institute has built an observatory at Warkworth, north of Auckland, equipped with a 12-metre and a 30-metre radio telescope.

A hallmark of Professor Gulyaev’s research is his collaborative approach with the IRASR forging working relationships with radio astronomy and national aeronautical organisations around the world, including NASA, SpaceX, ESA (European Space Agency) and JAXA (Japanese Space Agency).

In one of many collaborative projects Professor Gulyaev and his team have used a technique known as Very Long Baseline Interferometry (VLBI) to link the Warkworth radio telescope with observatories across Australia, including ASKAP (Australian SKA Pathfinder). Acting as one virtual radio telescope they were able to get greater resolution or sharper cosmic images from their observations.