Sad news today from Simon Portegies Zwart, who wrote the following orbituary:

It is with great sadness that I have to inform you of the passing away of Sverre Aarseth on 28 December this year after 90 two-body orbits. Sverre Johannes Aarseth was born on July 20, 1934, in Norway.

Sverre was a student of Fred Hoyle, and later became the supervisor of Douglas Heggie and Elena Terlevich at the University of Cambridge’s Institute of Astronomy. He pioneered computational astrophysics, developing the NBODY family of codes that revolutionized our understanding of planet formation, stellar clusters, the dynamics of black holes, and galaxy clusters. His work laid the foundation for numerous advancements in dynamical astronomy, earning him the prestigious Brouwer Award in 1998.

His commitment to open science was evident long before the concept of open-source software became popular, as he freely distributed and supported his codes. Generations of astronomers have benefited from Sverre’s codes. In recognition of his contributions, asteroid 9836 Aarseth (1985 TU) was named in his honor. Fittingly, Sverre is currently observable between Virgo and Lyra, a celestial tribute to his lasting impact on the field.

Beyond his scientific pursuits, Sverre was an avid mountaineer and accomplished chess player. He earned the title of International Master for Correspondence Chess in 1981. The astronomical community celebrated his 80th birthday in Sexten Italy in 2014, where we climnbed the Tre Cime di Lavaredo (also called der Drei Sinnen, a pathetic small mountain for Sverre), almost missing his afternoon talk.

Generations of astronomers were entertained by his vivid stories of meeting tigers (in the wild), racing cars, and stormy mountain top sleep-overs. His lively personality, humor, and groundbreaking work will be remembered fondly. As he ascends to a higher orbit, we will cherish the memory of his vibrant personality, captivating stories, and the invaluable codes he wrote. His legacy will continue to inspire future generations of astrophysicists, much like the celestial bodies he spent his life studying.

We have been lucky to have orbited Sverre.