BEGIN:VCALENDAR
X-LOTUS-CHARSET:UTF-8
VERSION:2.0
PRODID:-//unihamburg/mundry
METHOD:PUBLISH
BEGIN:VTIMEZONE
TZID:Europe/Berlin
X-LIC-LOCATION:Europe/Berlin
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:19700329T020000
RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=3
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:19701025T030000
RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=10
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
UID:127039
CLASS:PUBLIC
SUMMARY:COLLOQUIUM  Dan Stern, California Institute of Technology
DTSTART;TZID=Europe/Berlin:20251119T140000
DTEND;TZID=Europe/Berlin:20251119T153000
DTSTAMP:20260617T1326Z
DESCRIPTION:The Extremes of Quasar Variability:  Black Hole Mergers, Acquisitions, and Foreclosures\n
Variability is one of the key observational properties of quasars, recognized from their initial discovery in the 1960s. Variability probes of the fueling of their supermassive black hole engines, their physics, evolution, and environment. A new generation of synoptic sky surveys, in combination with the novel data analytics tools, offers unprecedented opportunities to study quasars in the time domain.  I will discuss quasars with extreme light curves, including quasars that likely host merging stellar mass black holes in their accretion disks; quasars that have gone through extreme brightening events, likely associated with the acquisition of stars that are torn apart as they wander too close to the black hole; and quasars that have turned off, or foreclosed, on surprisingly fast timescales.  The business of black holes is booming with existing surveys such as the Zwicky Transient Facility, eROSITA, and WISE -- and will expand yet further with surveys starting in the coming year and decade. \n
Talk in presence and via Zoom:\n
https://uni-hamburg.zoom.us/j/66006535328?pwd=aGkrSjJIYmZjK0VpYlpGL0ZrdHg2UT09 \n
\n
LOCATION:Hamburg Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Bibliothek
END:VEVENT
END:VCALENDAR