The International Astronomical Union Names an Asteroid After a Pope

March 13, 2023
The Vatican Observatory

The Working Group Small Bodies Nomenclature (WGSBN) – which reports to the International Astronomical Union (IAU) is responsible for assigning names to minor planets and comets. This is a functional working group, which exists beyond the normal three-year lifespan of IAU working groups.

According to the IAU, assigning a particular name to an asteroid is the result of a process that can, in some cases, take decades. When a new minor planet is discovered, it is assigned a provisional designation, based on its date of discovery.

When the object's orbit is sufficiently well determined that its position can be reliably predicted in the distant future, it is given a permanent designation number, issued sequentially by the IAU's Minor Planet Center.

Its discoverer is then invited to suggest a name. Names of pets or commercial names are not permitted. Names of individuals or events primarily known for their political or military activities may not be used until 100 years after the death of the individual or the occurrence of the event.

Naming rights cannot be purchased. Nominated names are judged by the WGSBN, which is made up of fifteen professional astronomers from around the world with research interests related to minor planets and comets.

Automated search efforts have discovered thousands of new asteroids, so the WGSBN must limit the number of those given official names. Thus, most asteroids only receive a numerical designation.

Three astronomers from the Vatican Astronomical Observatory, as well as a pope with ties to the observatory, now have asteroids named after them. On February 7, 2023, the WGSBN released its latest batch of named asteroids (WGSBN Bulletin 3, #2), which includes:

– 560974 Ugobuoncompagni – in honor of Ugo Buoncompagni (1502-1585), known as Gregory XIII, who led the reform of the calendar and initiated the tradition of papal astronomers and observatories. He asked Fr. Christopher Clavius, S.J. (who already has an asteroid named in his honor) to study the calendar, which led to the publication of the “Gregorian” calendar.

– 562971 Johannhagen – in honor of Fr. Johann Hagen (1847-1930) of the Society of Jesus (S.J.) and director of the Vatican Observatory from 1906 to 1930.

– 551878 Stoeger – in honor of Fr. Bill Stoeger, S.J. (1943-2014), cosmologist and theologian at the Vatican Observatory.

– 565184 Janusz – in honor of Fr. Robert Janusz, S.J. (b. 1964), currently a staff member of the observatory.

More than 30 asteroids today bear the name of Jesuits, such as Fr. Giovanni Battista Riccioli (1598-1671), who developed the system of lunar nomenclature still used today (for example, when the Apollo 11 mission landed in the lunar “Sea of Tranquility,” the name “Tranquility” came from Riccioli).

Monument to Gregory XIII in St. Peter's Basilica