Dr Kazimieras Černis, a researcher at the Institute of Theoretical Physics and Astronomy of the Faculty of Physics at Vilnius University (VU), named the asteroid in honour of St. Casimir, the first saint and patron saint of Lithuania. The asteroid was actively observed at various observatories between 2013 and 2019, and its orbit was finally determined in 2024. 

“We discovered the asteroid in 2013 at the Baldone Astronomical Observatory in Latvia together with Dr Ilgmārs Eglītis. It will be clearly visible again in September this year in the constellation Pisces, near the border of the constellation Aquarius,” says the astronomer. 

An extraordinary way to promote Lithuania 

This is not the first time Dr K. Černis has initiated the commemoration of important Lithuanian nobles and saints in space. The scientist and his colleagues have named over 150 asteroids, 100 of which have Lithuanian names or names related to Lithuanian history. 

“I chose to name the asteroid in honour of St. Casimir because of his historical and religious significance. Unfortunately, due to restrictions imposed by the International Astronomical Union, which registers the names of celestial bodies, my proposal to indicate in the name that it refers specifically to St. Casimir was rejected, so it was named “Casimir” rather than “St. Casimir,” without any indication of his status as a saint. I have already named other asteroids after kings and dukes, such as Algirdas and Vytautas. There are also asteroids which I named after saints who lived or visited Lithuania, such as St. Faustina, who lived in Vilnius, and the Polish saint Urszula Ledóchowska,” says Dr K. Černis. 

Dr Ilgmārs Eglītis and Dr Kazimieras Černis beside the Schmidt system telescope. Photo from the personal archive.

Cooperation with Latvian astronomers 

Astronomers from Vilnius University and Latvia have been collaborating for 17 years. According to the astronomer, during this time, around 60 asteroids have been discovered that need to be named, including some extremely rare asteroids. The scientists work together at the Baldone Observatory, located 30 kilometres south of Riga. 

“We have agreed with the Latvians that we will search for asteroids together at the Baldone Observatory and share our discoveries equally – they will suggest one name and we will suggest the other. We have been fortunate to discover not only many unnamed asteroids, but also rare and unique ones, such as the so-called centaurs. It is believed that they contain more ice than rocky material. The one we discovered orbits the Sun between Jupiter and Saturn and is approximately 70 kilometres in size. We discovered it in 2009 and named it Orius,” says the scientist. 

According to the Minor Planet Center database of the International Astronomical Union, asteroid (635483) “Casimir” is on average 2.20 times farther from the Sun than Earth and orbits the Sun in 3 years and 99 days (1193.74 days). Asteroid orbital elements: a = 2.202 AU, e = 0.132, i = 3.887°, P = 1193.74 days (3.27 m.). 

The International Astronomical Union announced that the asteroid, provisionally designated 2013 RU34 (635483), would be named “Casimir” at the suggestion of Dr K. Černis. The citation for the name was published in the IAU Minor Planet Center's electronic circular (MPEC) and WGSBN Bulletin 2025.