[Astronomy seminar] No astronomy seminar this week

[Astronomy seminar announcements]

NO Astronomy Seminar this week. However, there will be an astrobiology 
talk at Nordita on Friday April 12 at 15:15:

Time & location: Friday April 12, 15:15 in 112:028 (Nordita south)

Title: The Messenger: a galactic centre gravitational-wave beacon

Speaker: Marek Abramowicz (Gothenburg U & Nikolaus Copernicus Center)

Abstract:
Our existence in the Universe resulted from a rare combination of 
circumstances. The same must be true for any advanced extraterrestrial 
civilisation. If there exist any in the Milky Way, they are likely 
scattered over large distances in space and time, however, they must be 
aware of the unique property of the Galactic centre: it hosts the 
closest massive black hole to anyone in the Galaxy. A sufficiently 
advanced civilisation may have placed material in orbit around this 
black hole to study it, extract energy from it, and/or for communication 
purposes. In either case, its orbital motion will necessarily be a 
source of gravitational waves. Here we show that a Jupiter-mass 
"Messenger" on the innermost stable circular orbit around the black hole 
can be sustained for a few billion years by the energy output of a 
single star and emits an unambiguously artificial (continuous) 
gravitational wave signal that will be observable with LISA-type detectors.

Other upcoming activities:
19/4 (Fri): Good Friday, no seminar
26/4 (Fri) @ 10:30: Ernst de Mooij (Dublin)
26/4 (Fri) @ 13:00: PhD defence of Tine Libbrecht in FB52