BEGIN:VCALENDAR
VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-6936
DTSTART:20220506T170500Z
DURATION:PT1H0M0S
DTSTAMP:20260414T114411Z
LAST-MODIFIED:20220427T170413Z
LOCATION:2241 Chamberlin Hall
SUMMARY:Hot Atmospheres of Cool Stars: From Physical Conditions to Phy
 sical Processes\, Plasma Physics (Physics/ECE/NE 922) Seminar\, Dr. Na
 ncy S. Brickhouse\, 2022 Distinguished Alumni Awardee\, Senior Science
  Advisor Center for Astrophysics\, Harvard University & Smithsonian
DESCRIPTION:Observations of cool star atmospheres show a broad range o
 f physical conditions\, with some stars having peak electron temperatu
 res around a few MK like the Sun\, while others show peaks above 20 MK
 . The X-ray luminosities of some quiescent coronae are as much as five
  orders of magnitude larger than the Sun’s. For the past three decad
 es we have used ultraviolet and X-ray spectrometers to determine the p
 hysical conditions ---electron temperature\, electron density\, elemen
 tal abundances --- for a relatively small sample of cool stars (mostly
  the brightest). The youngest stars show a hot accretion shock in addi
 tion to an active corona\, although the resolving powers of instrument
 s to date are not sufficient to cleanly separate the two components. W
 e are proposing Arcus\, a NASA medium-scale explorer mission (MIDEX)\,
  to study structure and evolution in the Universe. Arcus will host a g
 rating spectrometer of sufficient spectral resolution to go beyond the
  measurement of physical conditions to the exploration of the physical
  processes that produce the high energy emission. 
URL:https://www.physics.wisc.edu/events/?id=6936
END:VEVENT
END:VCALENDAR