YTTHACA: YSOs at Tübingen, Tautenburg, Hamburg & ESO – A Coordinated Analysis

• Applicants: Dr. Jochen Eislöffel, since 8/2023; Dr. Carlo Felice Manara; Professorin Dr. Beate Stelzer
• Subject Area: Astrophysics and Astronomy
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 469334657

The properties of young stars and their circumstellar disks are key to understand planet formation. Measuring the conditions for planet formation are the goals of the HST legacy program ULLYSES and our VLT large program PENELLOPE (P.I. C.F. Manara). ULLYSES will use 500 orbits to observe 82 young (age < 10 Myr) stars at UV wavelengths complemented by PENELLOPE, which will obtain 250 h of optical and near-infrared spectroscopy for the ULLYSES targets contemporaneously with HST. This unprecedented database will be complemented by TESS lightcurves for all targets, and many other smaller observing campaigns are providing supplementary data. We propose to utilize the unique opportunity of this multi-wavelength dataset for a comprehensive study combining our complementary expertise in the field of young stars. To this end, we have developed a program that explores different facets of variability to probe the physical conditions throughout YSO evolution. Specifically, we propose to a) determine the stellar and accretion properties of YSOs from spectroscopy and photometric time-series, and constrain their variability on day, month, year and secular time-scales b) study the outflow properties of these targets and decipher their variability and time evolution from multiple tracers at different wavelengths c) derive the dust properties from a detailed modelling of the extinction law at different ages, which directly relates to the building blocks of forming planets d) measure how the outflow-to-accretion rate evolves with age using results from a) and b). The outflow-to-accretion rate depends on the accretion mode through the disk and, perhaps, the disk structure, again directly impacting the conditions for planet formation.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Dr. Christian Schneider, until 8/2023