BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Osservatorio Astronomico di Roma - ECPv6.15.18//NONSGML v1.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-ORIGINAL-URL:https://www.oa-roma.inaf.it
X-WR-CALDESC:Eventi per Osservatorio Astronomico di Roma
REFRESH-INTERVAL;VALUE=DURATION:PT1H
X-Robots-Tag:noindex
X-PUBLISHED-TTL:PT1H
BEGIN:VTIMEZONE
TZID:Europe/Rome
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20170326T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20171029T010000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20180325T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20181028T010000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20190331T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20191027T010000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=Europe/Rome:20180112T114500
DTEND;TZID=Europe/Rome:20180112T124500
DTSTAMP:20260406T172019
CREATED:20171215T072607Z
LAST-MODIFIED:20171215T072607Z
UID:3845-1515757500-1515761100@www.oa-roma.inaf.it
SUMMARY:Not all stars are the Sun: rethinking the Mixing Length
DESCRIPTION:Characterizing heat transport in stars is notoriously complicated\, and the task of reproducing the physics involved with high precision on stellar evolutionary timescales is a long-standing problem in stellar modeling. For this reason\, convection in 1-D stellar evolution codes is addressed primarily through a framework known as mixing length theory (MLT). In this simplified picture\, the efficiency of convective heat transport is encapsulated by the mixing length parameter alpha_{MLT}\, measured in pressure scale heights.\nWhile it is well understood that our nearest star is not a valid representation of stars in general\, it remains the standard procedure to calibrate alpha_{MLT} according to solar specifications\, and then to apply this value in any stellar model\, regardless of mass or composition. However\, there has been growing evidence that the use of a solar-calibrated mixing length is not always appropriate.\nIn this study\, we investigate the scope of validity of a solar-calibrated mixing length over a range of evolutionary phases and input physics for very metal-poor stars\, and find that the solar-calibrated mixing length is widely ineffective at reproducing the observed properties of such stars.
URL:https://www.oa-roma.inaf.it/event/seminar-by-meridith-joyce/
LOCATION:Aula Gratton
CATEGORIES:Seminari
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Rome:20180112T114500
DTEND;TZID=Europe/Rome:20180112T124500
DTSTAMP:20260406T172019
CREATED:20171215T072607Z
LAST-MODIFIED:20171215T072607Z
UID:4743-1515757500-1515761100@www.oa-roma.inaf.it
SUMMARY:Not all stars are the Sun: rethinking the Mixing Length
DESCRIPTION:Characterizing heat transport in stars is notoriously complicated\, and the task of reproducing the physics involved with high precision on stellar evolutionary timescales is a long-standing problem in stellar modeling. For this reason\, convection in 1-D stellar evolution codes is addressed primarily through a framework known as mixing length theory (MLT). In this simplified picture\, the efficiency of convective heat transport is encapsulated by the mixing length parameter alpha_{MLT}\, measured in pressure scale heights.\nWhile it is well understood that our nearest star is not a valid representation of stars in general\, it remains the standard procedure to calibrate alpha_{MLT} according to solar specifications\, and then to apply this value in any stellar model\, regardless of mass or composition. However\, there has been growing evidence that the use of a solar-calibrated mixing length is not always appropriate.\nIn this study\, we investigate the scope of validity of a solar-calibrated mixing length over a range of evolutionary phases and input physics for very metal-poor stars\, and find that the solar-calibrated mixing length is widely ineffective at reproducing the observed properties of such stars.
URL:https://www.oa-roma.inaf.it/event/seminar-by-meridith-joyce-2/
LOCATION:Aula Gratton
CATEGORIES:Seminari
END:VEVENT
END:VCALENDAR