The Pepsi Exoplanet Transit Survey (PETS@LBT) Workshop is scheduled on
Tuesday Sep 22 – 6am to 9am AZ time (13:00-16:00 UTC)
In this Workshop, we will discuss and wrap-up our community proposal for a large LBT program, to be submitted shortly thereafter. We propose a high-resolution spectroscopic survey of exoplanet transits, secondary eclipses, and host-star characterizations of selected targets; dubbed the “PEPSI/LBT Exoplanet Transit Survey (PETS)”. Immediate goal is characterizing the planetary and stellar atmospheres in detail. During this 3-hr Zoom meeting we shall emphasis again the strengths and uniqueness of this proposal and recall shortcomings. The survey requests 40 nights in total or 12.5 nights per semester for two years in order to observe a representative number of targets starting in semester 2021A.
The 33 meters long (in A0 format) spectrum of epsilon Eridani is available for download. See the Wallposters section among the Library links. Note that the whole spectrum is in two PDF files, each having a size of almost 18 MB.
9 January 2018. The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first batch of high-spectral resolution data to the scientific community. In a series of three papers in the European journal Astronomy & Astrophysics, the PEPSI team presents a new spectral atlas of the Sun, a total of 48 atlases of bright benchmark stars, and a detailed analysis of the chemical abundances of the 10-billion year old planet-system host Kepler-444.
During the first use of PEPSI-POL for science, we achieved a shutter-open-time of 91% during the night October 13/14, 2017. “Open-shutter time” is the time when photons are being collected on an instrument’s detector for later scientific use. As far as we know this is by far the highest at LBTO so far. The total available observing time from twilight to twilight on October 13/14 was 9 hours and 42 minutes of which 8 hours and 50 minutes were used to expose five different targets.
The installation of PEPSI at the LBT was completed on September 6th when both its polarimeters were mounted in the straight foci of the LBT. During the night of September 10, 2017 the telescope was pointed to the magnetic standard star gamma Equ and a series of integrations in circularly and linearly polarized light were obtained. These spectra have a spectral resolution of R=120,000, covered four wavelength regions in the optical (two always simultaneously) and reached a S/N ratio of up to 600:1 in 6 min integrations. The telescope was just tracking and not guiding yet nor were the wavefront sensors actively collimating the telescopes. The image quality was controlled by eye (by John Hill remotly from Tucson). Because the polarimeters for each of the LBT telescopes are identical and modular in design, circular and linear polarization may be obtained simultaneously. We used the SX side for circular and the DX side for linear polarization. A total of 12 exposures were obtained.
August 21, 2017. The partial solar eclipse was observed at Mt.Graham in Arizona remotely from AIP with the Solar Disk Integrated Telescope (SDI) which guides on the Sun and feeds the light into the PEPSI high-resolution spectrograph in the pier of the LBT telescope. The partial eclipse began on 09:16 MST and ended at 12:03 MST.
One hundred spectra were obtained during the course of the eclipse in two wavelength regions 422-477 and 536-628 nm with the resolving power 270 000 (1100 m/s in radial velocity per resolution element). The spectra obtained are highly dynamic as the area of the line formation changes, hence, the shape of the lines is slightly alternating. We perform analysis of the Sodium D1 line 589.59 nm which is formed in the lower chromosphere of the Sun above 500 km of its photosphere. Its bisector (i.e. the central wavelength at different depths of the line profile) shows large changes in the line core which is formed in the higher chromospheric layers.