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Project Progress

As in previous years, my major effort during the past year continuesto be the preparation of the VYSOS project. VYSOS (Variable YoungStellar Objects Survey) consists of a 20 inch telescopes,mounted in Hawaii at Mauna Loa and a 16 inch telescopealready mounted in Chile at Cerro Armazones. The northern telescope is ownedand operated by me, and the southern telescope is owned and operatedby Rolf Chini, a colleague at the Ruhr-Universitat Bochum in Germany.The goal of our project is to have these two fully robotic telescopesmonitor all star forming regions along the entire Galactic planewithin about 2 kpc in order to understand the photometric variabilityof solar-like young stars. Such variability can have a number ofcauses, mainly accretion activity, starspots, eclipses by companionsor dustclouds, and magnetic reconnection events. Almost nothing isknown about the timescales and amplitudes of these phenomena, and theVYSOS project will put this on a firm footing by monitoring many tensof thousands of young low-mass stars over the next decade ormore.

To survey larger swaths of the sky, we have installed a 135 mmapochromatic refractor at the Mauna Loa Observatory. It has a 2.9 ×2.9 degree field and can reach 17th magnitude in 5 min exposures. Weare currently performing surveys of large areas of the Milky Way withthis telescope, together with a similar survey done by a 150 mmrefractor installed at our site in Chile. These small but highlyefficient telescopes will also be used for monitoring bright comets asthey enter the inner Solar System. Our northern refractor alone hasalready obtained over 30,000 images in the past 16 months. We havealso developed an all-sky camera that allows us to monitor theobserving conditions via the internet.

During the past year we have received a grant that has allowed us toorder a second 135 mm apochromatic refractor, and we expect deliveryin a few months. This will be mounted next to the first refractor, andthe two will perform simultaneous observations in an r- and ani-filter, so we get information not only on variability but also oncolor changes. We have also performed repairs and have improved thedrive system for the two domes.