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BEGIN:VEVENT
DTSTART;TZID=Atlantic/Canary:20221117T103000
DTEND;TZID=Atlantic/Canary:20221117T113000
UID:iactalks-1626
X-WR-CALNAME: IAC Talks: Open Astronomy Seminars
X-ORIGINAL-URL: /iactalks/Talks/view/1626
CREATED:2022-11-17T10:30:00+00:00
X-WR-CALDESC: IAC Talks upcomming talks
SUMMARY:The scattering properties of dust in distant comets
DESCRIPTION:The scattering properties of dust in distant comets\nDrs. Oleks
 andra Ivanova\n\nThe Oort cloud and the Edgeworth-Kuiper belt are two main
  reservoirsthat supply new comets to the inner region of the Solar System.
  Some ofthe cometary nuclei demonstrate significant activity at heliocentr
 icdistances beyond 5 au. It is of great interest to determine the reasonsf
 or this. Since 2011 we have provided a comprehensive program ofpolarimetri
 c, photometric, and spectral investigations of active distantcomets at the
  6-m telescope BTA. We present the results of broadbandpolarimetric measur
 ements for seven distant comets C/2011 S1 (LINEAR),C/2011 R1 (LINEAR), C/2
 014 A4 (SONEAR), C/2013 V4 (Catalina), C/2012 J1(Catalina), C/2011 KP36 (S
 pacewatch), and C/2014 B1 (Schwartz) whichhave perihelion distances of mor
 e than 3 au. The comets show significantactivity beyond the Jovian orbit. 
 Polarization maps of the cometsdemonstrate spatial variations of linear po
 larization over the coma fromabout –2% up to –7% at phase angl
 es from 2 to 20 degrees that may berelated to changes in the physical prop
 erties of dust particles. Averagepolarization values are significantly hig
 her (in absolute values) thanthe typical value of polarization (∼1.5%)
  observed for the whole coma ofmost comets that approach closer to the Sun
 . Probably dust in distantcomets differs from the dust in short-period com
 ets. We also compare thepolarimetric observational data with the results o
 f numerical modelingperformed early for different types of dust aggregates
 .\n------------------------------------------------\nZOOM: https://rediris
 .zoom.us/j/89675933678?pwd=QnptWjNYNzNZQ3V6MFl6SDdjOUFCQT09   Meeting ID: 
 896 7593 3678  Passcode: 334513 \n \nYouTube: https://youtu
 .be/gjpr7YVmfJA\n
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