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<div class="" style="margin-top: 0px; margin-bottom: 0px;"><font class="" size="3">Dear all,</font></div>
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<div class="" style="margin-top: 0px; margin-bottom: 0px;"><font class="" size="3"><font color="black" class="">our next and last Extreme Object meeting before the summer break will be held </font><font color="black" class=""><b class="">next Thursday, 16th
of April, at 13:15 (CET).</b></font><font color="black" class=""> The speaker is </font><font color="#333333" class=""><font class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-style: normal;" class=""><b class="">Wynn Jacobson-Galan</b></span><span style="color: rgb(29, 28, 29); font-variant-ligatures: common-ligatures; orphans: 2; widows: 2; text-decoration-thickness: initial;" class=""> a
fellow researcher from Berkeley visiting us in Stockholm next week</span>. </font></font></font></div>
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<div class="" style="margin-top: 0px; margin-bottom: 0px;"><font size="3" class=""><font class="">The meeting will be held </font><font class="">in</font><font class=""><font class=""> <b class="">hybrid </b></font><b class="">mode</b></font><font class=""> at
the </font><span class=""><b class="">Albano 3:6228 - Mega </b></span><font class=""><span class=""><b class="">room</b><font class="">. </font></span></font><font class=""><span class=""><font class=""><i class="">Some directions</i> f</font></span></font><span class="" style="font-variant-ligatures: common-ligatures; orphans: 2; widows: 2; text-decoration-thickness: initial;">or
those that have never been in the Mega room, it is located in Nordita (<b class="">floor 6 house 3</b>), if you enter from the door on the right of the elevator it is just there. I will be a little in advance to set up the room, and I can open the door for
people with no access. </span></font></div>
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</font></font></div>
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<div class="" style="margin-top: 0px; margin-bottom: 0px;"><font color="#212121" class=""><font color="black" class="" size="3"><span lang="en-US" class=""><b class="">To join the meeting online:</b></span></font></font></div>
<div class="" style="margin-top: 0px; margin-bottom: 0px;"><font color="#212121" class=""><font color="black" class="" size="3"><span lang="en-US" class=""><a href="https://stockholmuniversity.zoom.us/j/65883589027?pwd=RGxJOUVQWmNtMlZFMUIwaHRabkExdz09" class="">https://stockholmuniversity.zoom.us/j/65883589027?pwd=RGxJOUVQWmNtMlZFMUIwaHRabkExdz09</a></span></font></font></div>
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<div class="" style="margin-top: 0px; margin-bottom: 0px;"><font color="#212121" class="" size="3"><font color="black" class=""><span lang="en-US" class=""><b class="">Meeting ID:</b></span></font><font color="black" class=""><span lang="en-US" class=""> 658
8358 9027</span></font></font></div>
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<div class=""><font size="3" class=""><span style="font-style: normal;" class=""><b class="">Title</b>: Watching a Star Explode with the Young Supernova Experiment</span></font></div>
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<div class=""><font size="3" class=""><span style="font-style: normal;" class=""><b class="">Abstract</b>: We present multi-wavelength observations of supernova (SN) 2020tlf, the first normal type II-P/L SN with confirmed precursor emission, as detected by
the Young Supernova Experiment (YSE) transient survey. The detected pre-explosion emission for ~130 days prior to SN is consistent with either a super-Eddington progenitor wind or a wave-driven eruption. Soon after discovery, “flash” spectroscopy of SN 2020tlf
revealed prominent narrow emission lines from shock-ionized circumstellar material (CSM) shed in progenitor mass-loss episodes in the final months before explosion. Following classification, SN 2020tlf was observed in a thorough multi-wavelength follow-up
campaign in UV/optical/IR, radio and X-ray bands out to a +300 days after explosion. The nebular phase spectra of SN 2020tlf constrain the possible mass of the red supergiant progenitor to 10-12 Msun. Finally, we present radiative transfer modeling of the
SN light curve and spectral evolution, which reveals that the progenitor star had an extended envelope, detached CSM and a heightened mass loss rate. We will discuss how the progenitor and CSM properties of SN 2020tlf fits within the phase space of the small
but growing number of SNe with “flash” spectroscopy and pre-explosion eruptions. Furthermore, we will discuss the physical processes capable of producing such luminous precursor emission in a red supergiant in the final year(s) before explosion. </span></font></div>
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<div class="" style="margin: 0px;"><span class="" style="font-family: Slack-Lato, Slack-Fractions, appleLogo, sans-serif; orphans: 2; widows: 2;"><font size="3" class="">Kind regards,</font></span></div>
<span class="c-mrkdwn__br" data-stringify-type="paragraph-break" style="box-sizing: inherit; display: block; height: 8px; font-family: Slack-Lato, Slack-Fractions, appleLogo, sans-serif; font-variant-ligatures: common-ligatures; orphans: 2; widows: 2; text-decoration-thickness: initial;"></span><span class="" style="font-family: Slack-Lato, Slack-Fractions, appleLogo, sans-serif; font-variant-ligatures: common-ligatures; orphans: 2; widows: 2; text-decoration-thickness: initial;"><font size="3" class="">Ana
Sagués Carracedo & Haakon Andresen</font></span></div>
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