Like nearly all stellar astronomers, the members of the Section of Variable Stars and Exoplanets of the Slovak Astronomical Society at the Slovak Academy of Sciences and the Slovak Union of Astronomers (hereafter “the Section”) eagerly awaited the eruption of the recurrent nova T CrB predicted for 2024. They did not merely wait passively but had prepared photometric and spectroscopic detectors. They regularly monitored the object. But the eruption has not occurred yet. Nevertheless, recurrent novae and novae in general form an important part of this report. An interesting activity has emerged – a campaign that unexpectedly connects variable star observers with astrophotographers.
One part of the story of this campaign begins at the conference on symbiotic stars and peculiar novae, organized by our member Jaroslav Merc in Prague from June 3–7, 2024. The author of this report was intrigued by the contributions of a group led by Prof. Michael Shara, currently working at the American Museum of Natural History. Their contributions dealt with the search for extremely faint remnants of repeated nova outbursts. Today, we know that practically every nova erupts repeatedly, and in between outbursts behaves like some type of cataclysmic binary. Theory predicts that the interaction of the tenuous gas expanding after repeated outbursts forms shock waves, which are the source of electromagnetic radiation. Prof. Shara’s group even built a battery of telescopes to experimentally confirm the existence of such super-shells (Nova super-remnants). From what has been published so far, we know that genuine Nova super-remnants have been confirmed for the most frequently erupting recurrent nova M31N 2008-12a and for KT Eridani. And most recently, probably also for T CrB itself.
The second, parallel, part of the story relates to the development of astrophotographers’ capabilities. This mainly involves achieving extremely long exposures through narrowband filters. They reveal unknown stellar streams around galaxies, planetary nebulae, and supernova remnants in unprecedented detail. Coincidentally, at Kolonica Saddle this year, we opened an astrophotography pavilion dedicated specifically to such advanced astrophotographers. It quickly filled with instruments designed for imaging large extended objects. Naturally, the idea of joining the search for Nova super-remnants did not take long to appear. Thus, today we have a joint campaign of the Variable Star Section and the Astrophotography Section. Details are available on the campaign coordination website: https://astrophoto.kozmos.sk/
As for the activities of the Section members, 19 papers co-authored by our members were published. In 11 cases, a Section member was the first author. A fine result for 20 members. A significant part of them was included in the proceedings of the conference on observing techniques, instruments, and research with small telescopes held in the Tatras in 2023.
The main event where Section members could personally participate was the Variable summer school, held in July at the Astronomical Observatory at Kolonica Saddle, again under the professional guidance of Theodor Pribulla. This time it focused on processing satellite data and linking them with ground-based observations. The event report is published at: https://variable.astrokolonica.sk/sk/2024-kolonica-26-jul-3-august-satelitne-data/.
The traditional Kolos conference was also held, organized under the leadership of the Vihorlatská Observatory in Humenné. Five Section members actively participated. The conference report is available at: https://kolos.astrokolonica.sk/kolos-2024-report/.
Looking Ahead to 2025
In 2025, we will continue monitoring T CrB. Traditional events will also take place. Please note the dates:
– Variable: 25 July – 2 August 2025
– Kolos: 6–8 November 2025
Kolonica, 14 January 2025
Pavol A. Dubovský
Chairman of the Section