First Light for PEPSI

22 April 2015. The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) has received its first celestial light through the Large Binocular Telescope (LBT). Astronomers from the Leibniz Institute for Astrophysics Potsdam showed the instruments incredible capabilities at different wavelengths and resolving powers. Among the first targets were several of the bright Gaia-ESO benchmark stars, magnetically active stars, solar-like stars with planets, a solar twin in M67, Jupiter’s four Galilean moons, and the bright Nova Sgr 2015b.
First Light for PEPSI

Spectrum of HD 82106 in comparison to other AIP observatories.

On April 1st, the 2 x 8.4m mirrors of LBT, effectively an 11.8m telescope, were turned to the K3 dwarf star HD 82106, and PEPSI received its first celestial photons through the world’s largest telescope. The instrument splits the stellar light into a spectrum with a wavelength resolution otherwise only obtainable in solar physics. The commissioning team of four AIP astronomers on the 3200m Mt. Graham in Arizona was preceded by a team of five who prepared the instrument for this event.

The star was only the first in a series of commissioning targets that test the instrument’s resolving powers at different wavelengths. Switching between resolution modes or between wavelength settings takes less than a minute and can be done any time. PEPSI is the only instrument that enables astronomers to point to bright stars as well as to faint quasars during the same night.




Caption: Star spectrum of HD 82106 compared to the Sun and Arcturus (detail).

Science Contact and Principal Investigator: Prof. Dr. Klaus G. Strassmeier

Project scientists: Dr. Ilya Ilyin and Dr. Michael Weber

Media contact: Dr. Janine Fohlmeister, +49 331 7499 383

The key topics of the Leibniz Institute for Astrophysics Potsdam (AIP) are cosmic magnetic fields and extragalactic astrophysics. A considerable part of the institute's efforts aim at the development of research technology in the fields of spectroscopy, robotic telescopes, and e-science. The AIP is the successor of the Berlin Observatory founded in 1700 and of the Astrophysical Observatory of Potsdam founded in 1874. The latter was the world's first observatory to emphasize explicitly the research area of astrophysics. Since 1992 the AIP is a member of the Leibniz Association.