Observational Facilities and Stellar Characterization Capabilities at Tartu Observatory

<p>Tartu Observatory telescopes offer unique guaranteed access to objects in the Northern hemisphere. The observational facilities include a 1.5- m and 0.6-m classic Cassegrain reflectors, and 0.31-m remotely controllable telescope .</p> <p>&#160;The 1.5 m telescope is currently equipped with a long-slit Cassegrain spectrograph used for stellar characterisation. Historically, the objects of interest have been massive stars but we are now developing new research direction and expanding the list of targets to exoplanet- and disk-hosting stars.</p> <p>We have started evaluating our capabilities to characterise host stars spectroscopically to determine their parameters and composition. In 2020, we carried out a pilot study of a TESS candidate planet host, which we found to have a rare, strong chemical peculiarity [1]. This also allowed us to prepare our tools, workflow, and end-to-end analysis. We are also contributing to the European Space Agency Ariel space mission by offering stellar activity monitoring.</p> <p>The 0.6-m and 0.31-m telescopes are utilised for photometric measurements and the 0.31-m one in particular has been a workhorse for exoplanet transit monitoring. Since 2020, we have made significant preparations to develop and prove our transit observation capabilities: we have observed more than 70 transit light curves. About&#160; half of them have been submitted to ExoClock to contribute to Ariel mission planning.</p> <p>Concerning future upgrades, Tartu Observatory will have new instruments by the middle of 2023. The upgrades include procuring a medium resolution echelle spectrograph (projected bandwidth 390 nm to&#160; 750 nm, R= 25 000) and new photometer (Johnson-Cousins BVRI and SDSS filters) for the 1.5-m telescope, which will not only enhance our capabilities in both spectroscopic and photometric data retrieval of host stars. In addition, a new remote control system of the telescope will be installed and improvements on instrumentation for the 0.6-m and 0.31-m photometric telescopes will be made.&#160;</p> <p>This presentation will give an overview of our facilities, and of current and future spectroscopic and photometric capabilities.</p> <p>&#160;</p> <p>References:</p> <ul> <li>&#8220;A rare phosphorus-rich star in an eclipsing binary from TESS&#8221;, Colin P. <em>et al.</em>, A&A <strong>658</strong> A105 (2022), DOI: 10.1051/0004-6361/202142124</li> </ul>