2021 – Kolonica 31 July – 8 August “From Argelander to Savanevych”


EvaPopardovskáSR, SPHE3
VladimírPopardovskýSR, SPHE4
MartinPopardovskýSR, SPHE5
RobertBarsaSR, SAS5
TomislavChrenkoSR, Malacky3
IgorKudzejSR, Hvezdáreň Humenné
PavolDubovskýSR, SPHE
TomášMedulkaSR, Hvezdáreň Humenné


The astrocamp was organized by the Vihorlat Observatory with co-organizers, which were the Slovak Central Observatory, the Slovak Astronomical Society of the Slovak Academy of Sciences, the Slovak Union of Astronomers, the Faculty of Natural Sciences of the UPJŠ in Košice and the Non-Investment Fund Teleskop. The event took place from July 31 to August 8, 2021 at the Astronomical Observatory at Kolonica Saddle. It was also the first action of the newly established Section of Variable Stars and Exoplanets SAS at SAS and SZA (hereinafter Section). In keeping with its name, astrocamp is aimed at observing variable stars. The observatory is excellently equipped for this purpose. There are a number of telescopes for visual observation, CCD photometry, and a low-resolution slit spectrograph LISA was also available for participants. After a long time, the participants were purely Slovaks. Traditional participants from Ukraine and Poland did not arrive due to travel restrictions in place. Eventually, a group of eleven enthusiasts gathered at Variable, four of whom are already members of the Section and the others will soon become them. The organizational leader of the astrocamp was RNDr. Igor Kudzej, CSc., director of the Vihorlat Observatory. The expert leader was the chairman of the Section himself, Pavol A. Dubovsky. The technical provision of the astrocamp was in charge of another employee of the Vihorlat Observatory, Tomáš Medulka.

In terms of content, Variable astrocamp consists in solving research tasks that participants choose from the offered list. The tasks are built in such a way that the solver should go through the whole process from theoretical preparation, through practical observation, data analysis to presentation of results. Astrocamp is thus actually a training camp in which participants increase their knowledge and skills and, on the other hand, provide their own experience to colleagues. In the end, each participant gained an overview of all solved tasks and thus a comprehensive overview of the methods of research of variable stars. The title of the astrocamp “From Argelander to Savanevych” was also written on the invitation. That is, from simple methods of visual observation to sophisticated processing of CCD photometry developed by a group of Ukrainian programmers led by prof. Savanevyč with the active help of astronomers from the Vihorlat Observatory.

This year, out of five tasks announced, participants chose four. So they formed four groups. The visual group consisted of a single participant, Peter Veress, who focused on visual estimates of cepheid brightness. It’s beautiful that anyone else is interested in observing with their own eyes at a time when everything takes place on computer monitors. Stanislav Šúst, Peter Cabuka and Tomáš Chrenko embarked on the routine task of determining the transformation coefficients for individual telescopes used for CCD photometry. The classic task of constructing O-C diagrams for eclipsing binaries was solved by Vladimír and Eva Popardovský. True only on archival data. Because they managed to get the whole light curve themselves only on the last night. They also tried to innovate. They compared the minima times obtained by various methods implemented in the MAVKA program with those obtained using a neural network created in the Matlab environment. An attractive topic about spectroscopy of variable stars attracted Robert Barsa and Martin Popardovský. Yes, the well-known Slovak astrophotographer devoted himself to spectroscopy. And he had the opportunity to experience how exciting this discipline is. It was during Variable that the so called P Cygni profile in the spectrum of Nova Vulpeculae 2021 (V606 Vul) appeared overnight in the emission lines.

Thus, the stars themselves wished astrocamp with their activity. In addition to the aforementioned nova, it was also possible to observe the extremely slow nova V1405 Cas and at the same time the extremely fast nova V1674 Her. It was worse with conditions in the Earth’s atmosphere. Only the last night was completely clear. Until then, every hole in the clouds had to be exploited.

The last evening at Variable includes the presentation of the final presentations of individual researchers and the Jindřich Šilhán Prize for an exemplary approach to observing variable stars. This time, Stanislav Šúst, a recent graduate of post-secondary studies in astronomy, was awarded. However, we are pinning our hopes on the whole group of astronomers – variable stars observers, that has formed here. With such people, the activity of the Section of Variable Stars and Exoplanets will certainly be full of amazing experiences.