Barthel formally retired at the end of 2018, but he plans to continue working part-time.
A festive retirement concert took place in December 2018, in the Groningen Oosterpoort concert hall. The Groningen student symphony orchestra Mira, conducted by Pieter Bosma, played the Academic Fest Ouverture by Brahms, Tchaikovsky’s first piano concerto (with soloist Martin Oei) and Dvorak’s 7th symphony (picture: Elmer Spaargaren).
Together with his former colleague Mark Neeser, Peter Barthel produced several well-known astronomical photographs, using multi-band exposures with the FORS Camera of ESO’s Very Large Telescope. Three of these appeared together in ESO’s web release Three Dusty Beauties, whereas another one – the Sombrero Galaxy, Messier 104 – features in the top page of the website you are currently reading. The relevant web release is Fine Shades of a Sombrero. Several of these VLT images appeared as NASA’s APOD, Astronomy Picture of the day, such as Messier66.
Summarizing the views which he developed through many years of publicly discussing the relation between science and religion, and motivated by a question of a 7-year old elementary school pupil, Peter Barthel published his short, unique booklet “Professor, bestaat God?” (“Professor, does God exist?”) in 2017. Its third edition appeared in Spring 2019, and the English version is in preparation. Reviews can be found here.
At the occasion of the 4th centenary of Groningen University in 2014, Peter Barthel and his colleague George van Kooten organized the first ever interdisciplinary international scientific conference on Matthew’s story of the Star of Bethlehem and the Magi. The resulting book was published by Brill, and is available as hardback and paperback.
In winter 2010 Peter Barthel carried out a small project researching the moon phases as depicted on SantaClaus (Sinterklaas) gift wrap and books, and on Christmas cards, in The Netherlands and the USA. The resulting publication caused many smiles and substantial press coverage, including the Dec5 Pauw & Witteman talk show.
Together with his Groningen team Peter Barthel won the 2007-08 national Academische Jaarprijs for science communication, for their project “Discover the invisible universe”, explaining infrared radiation and infrared astronomy to school children and the public-at-large.
In 2014 Barthel won the national Willem de Graafprijs for his efforts in astronomy outreach and education.