Institute of Astronomy

ContactPiwnice k. Torunia, 87-148 Łysomice
tel.: +48 56 611 30 10
fax: +48 56 611 30 09

General Seminar (2023)

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General Seminar takes place every Monday at 11.15 in Piwnice, radioastronomy seminar room.
Remote participation via the BigBlueButton (BBB).

9 January 2023

Annual summary of the telescopes outcome in the Piwnice Observatory

dr hab. Agnieszka Słowikowska, prof. UMK, dr Paweł Zieliński, dr Karolina Bąkowska (Institute of Astronomy, Nicolaus Copernicus University)

During the last two years, the renovation of the 90-cm and 60-cm telescopes and recoating process of their mirrors took place. Additionally, the new instruments have been installed in the second dome and are ready for use. On the radio telescopes, the SPUB grant allowed the modernisation of the radio infrastructure. These challenging tasks ended with success, and the photometric and radio observations were resumed. We will present the outcome of the renovation, preliminary scientific results from the optical telescopes, ongoing projects and plans for these instruments in our institute. We encourage students and PhD students to participate in this seminar, as it will help you learn about a wide range of scientific collaboration opportunities.

16 January 2023

“Precise masses as fundamental parameter for planet structure, distributions and in-depth atmospheric studies”

dr Grzegorz Nowak (Instituto de Astrofísica de Canarias (IAC) Tenerife, Spain)

The basic characterisation of planets (internal structure, formation history and possible atmospheric composition) starts with a measurement of their masses and radii. The need to know both of these quantities is a motivation for a great development of the ground- and space-based transit surveys and for a continuous importance of the radial velocity (RV) technique, which together became a tandem of mutually supporting observing techniques. Having the three main planetary quantities, i.e. mass, radius and mean density, we are in a position to study the planets’ internal structure as well as their formation and evolution, by placing them within mass-radius and mass-density diagrams. Precise RV measurements from 3-4-metre class telescopes are fundamental in determining planetary masses, in filling these diagrams, and in explaining the large scatter in fundamental properties, especially for the smallest planets of 1-4 Earth radii.
In this talk I am going to present recent results of radial velocity follow-up of Kepler-K2 and TESS planet candidates with TNG/HARPS-N and CAHA/CARMENES instruments in a framework of KESPRINT and CARMENES consortia. These results include sub-Neptune planets around nearby M dwarfs LTT 3780 (TOI-732) and G 9-40 (K2-313, TOI-5097), an ultra-short-period, 1.7 R_Earth planet around a solar-type star HD 20329 (TOI-4524), sub-Saturn around G7V star K2-280, and a planetary system around G9V star HD 191939 (TOI-1339), including HD 191939 g – Uranus-mass planet in the habitable zone with an orbital period of ~300 days.

23 January 2023

“Cow, Camel and other explosive animals”

dr Mariusz Gromadzki (Astronomical Observatory, University of Warsaw)

An extensive development of all-sky surveys, in the last years, allowed discovery of fast, blue and very energetic extragalactic transients, which fade in a scale of a few weeks or shorter. In mid 2018, an enigmatic object was discovered AT 2018cow aka “Cow”, its untypicall evolution was systematically reported on Twitter and the nature of explosion for a long time remained a puzzle. Further, follow up observations solved the mystery and similar targets were discovered. “Cow” has become part of pop culture and the group of these transients got a nickname FBOTs (Fast Blue Optical Transients). In my talk I will present a brief review of this exciting topic.

30 January 2023

“Young open clusters asteroseismic potential”

dr Dawid Moździerski (Astronomical Institute, University of Wrocław)

Star clusters studies are known as a very good starting point for studies of stars themselves. I will briefly present the most interesting open clusters in terms of the asteroseismology of their members. Our latest results of the search for pulsating stars and their ensemble asteroseismology indicate, that young open clusters provide excellent conditions for asteroseismic studies of the parameters of stars and their interiors.

6 February 2023

“Progenitors of LGRBs: Are single stars enough”

MSc Rafia Sarwar (Institute of Astronomy, Nicolaus Copernicus University)

In recent years theoretical and observational stellar astrophysics strongly altered the paradigm of our current understanding of the life cycle of massive stars, from their birth in the dense interstellar medium to their final fate of collapsing into compact objects. If these compact objects are insufficiently close orbits, they start losing orbital energy via gravitational wave (GW) emission. Stellar evolutionary models are commonly used to infer the event rates of these gravitational waves statistically. Despite their significance, many if not all the evolutionary models of massive stars do not take in the final phase of the stellar explosion. The complexity of the problem is due to the intricate dependence of the explosion physics on the structure of the exploding star. Therefore, it is crucial to develop a new computer routine that associates stellar models with various types of supernovae in accordance with their explosion energies and ejecta mass. Here we present the preliminary results of Yoon et al. (2006), revised and expanded upon, including the new observational comparison for GRBs.