Dziewanna - the largest "Polish" object in the Solar System

In 2010, astronomers from the Astronomical Observatory of the University of Warsaw used a telescope at the Las Campanas Observatory in Chile to conduct observations of large sections of the southern sky. Their goal was to search for large objects on the outskirts of the Solar System. The project was conducted as part of one of the largest large-scale sky surveys in the world - the Optical Gravitational Lensing Experiment (OGLE), the project leader Prof. Andrzej Udalski reported in the release sent to PAP.

The result of this hunt was the discovery of over a dozen new objects with diameters reaching several hundred kilometres. One of them was given the technical designation 2010 EK139. Further research has shown that it is the largest "Polish" object in the Solar System, included in the list of the 40 largest independent objects of the system.

Discoverers have the privilege of naming a new object in the Solar System (after it is verified by the Minor Planet Center operating at the Harvard University under the auspices of the International Astronomical Union).

In recent years, small objects from the nearby regions of the Solar System have been discovered on a massive scale, with diameters rarely exceeding a few kilometres. Discoverers generally give them names of people or places. But in the case of distant trans-Neptunian objects, the Minor Planet Center applies a strictly defined naming scheme - they are named after deities from the mythologies of different nations.

"In 2010, after the press release about the discovery of this very interesting object, the issue of its naming attracted considerable attention" - reminds Prof. Udalski. But it turned out that the name Perun proposed in the Gazeta Wyborcza poll had already been used to name a much less impressive Solar System object, and Weles is too similar to an already existing asteroid name.

"When in 2017 our 2010EK139 was added to the list of objects that could be given their own names, we decided to follow this convention and find a name associated with Polish, or more generally Slavic deities in order to have a space object referring to our traditions" - describes Prof. Udalski.

The choice was the name of a young goddess appearing in various Slavic mythologies: Dziewanna, protector of wild nature, forests and woods, bringer of spring and new life. Her symbol is wild mullein, the plant that was used as torches during the festivities associated with the goddess.

"Although the name Dziewanna in other Slavic languages may be easier to pronounce for foreigners, we decided to use the Polish spelling to emphasize the Polish roots of our discovery and the OGLE project" - explains Prof. Michał Szymański, director of the Astronomical Observatory of the University of Warsaw and co-founder of the OGLE project.

After the official approval of the proposed name by the Minor Planet Center (a few days ago), 2010 EK139 no longer orbits in the Solar System, Dziewanna does.

If Dziewanna orbited the Earth instead of the Moon, its shield would have been only seven times smaller than the Moon. Its projection on the Earth`s surface covers almost the entire Poland.

"Discovering such large objects in the Solar System was extremely exciting" - remembers Professor Udalski. "As a rule, astronomers study inaccessible objects, located extremely far away from us. We felt almost like Columbus discovering new lands, because in a few hundred years it will certainly be easy to reach them" - he adds.

Soon after the discovery of 2010 EK139 it turned out that this object had already been registered a few years earlier, but it escaped the astronomers` attention. Thanks to the data from earlier observations, it was possible to determine its precise orbit around the Sun. It revolves around the Sun once in 593 years on a very elongated ellipse. The closest it gets to the Sun is 33 astronomical units (the astronomical unit is the Earth - Sun distance, 150 million km), the maximum distance is more than three times greater.

At the end of 2010, EK139 was still observed by the Herschel satellite to measure the reflectivity of its surface. It turned out that it reflects sunlight quite well - it is most likely partly covered with ice. The measurement also allowed to accurately determine the size of the minor planet - 470 km. It is one of the largest objects in the solar system discovered in recent years.

"I hope that putting Dziewanna in the sky will encourage researchers of Polish and Slavic traditions and cultures to learn more about this mysterious goddess" - adds Prof. Udalski. "Fantasizing even more - it might also encourage scientists, engineers or technical university students to design an extremely ambitious space project. (...) It would be very interesting to see the true face of our Dziewanna and learn its secrets" - he notes.

PAP - Science in Poland

ekr/ zan/ kap/

tr. RL