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Dear all,</div>
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<div style="font-size: 12pt; margin-top: 0px; margin-bottom: 0px;" class=""><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" size="3" color="black" style="font-family: Calibri, Helvetica, sans-serif, Helvetica, EmojiFont, "Apple Color Emoji", "Segoe UI Emoji", NotoColorEmoji, "Segoe UI Symbol", "Android Emoji", EmojiSymbols;" class=""><span style="font-size: 12pt;" class="">our
next Extreme Object meeting will be </span></font><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" size="3" color="black" style="font-family: Calibri, Helvetica, sans-serif, Helvetica, EmojiFont, "Apple Color Emoji", "Segoe UI Emoji", NotoColorEmoji, "Segoe UI Symbol", "Android Emoji", EmojiSymbols;" class=""><span style="font-size: 12pt;" class=""><b class="">next
Thursday, 21st of April, at 13:15 (CET).</b></span></font><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" size="3" color="black" style="font-family: Calibri, Helvetica, sans-serif, Helvetica, EmojiFont, "Apple Color Emoji", "Segoe UI Emoji", NotoColorEmoji, "Segoe UI Symbol", "Android Emoji", EmojiSymbols;" class=""><span style="font-size: 12pt;" class=""> The
speaker is </span></font><span style="font-family: Calibri, sans-serif; font-size: 14.666666984558105px;" class=""><b class="">Tuomas Kangas</b></span><font size="2" color="#333333" class=""><span style="font-size: 17px;" class=""><font face="wf_segoe-ui_normal, Segoe UI, Segoe WP, Tahoma, Arial, sans-serif, serif, EmojiFont" class=""> from
KTH. </font></span></font><font face="Calibri, Helvetica, sans-serif, Helvetica, EmojiFont, Apple Color Emoji, Segoe UI Emoji, NotoColorEmoji, Segoe UI Symbol, Android Emoji, EmojiSymbols" class="">He will talk about his recently submitted paper on hydrogen-</font><span style="font-family: Calibri, Helvetica, sans-serif, Helvetica, EmojiFont, "Apple Color Emoji", "Segoe UI Emoji", NotoColorEmoji, "Segoe UI Symbol", "Android Emoji", EmojiSymbols; font-size: medium;" class="">rich</span><font face="Calibri, Helvetica, sans-serif, Helvetica, EmojiFont, Apple Color Emoji, Segoe UI Emoji, NotoColorEmoji, Segoe UI Symbol, Android Emoji, EmojiSymbols" class=""> superluminous
supernovae. </font></div>
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</span></font></div>
<div style="margin-top: 0px; margin-bottom: 0px;" class=""><font face="Calibri, Helvetica, sans-serif, Helvetica, EmojiFont, Apple Color Emoji, Segoe UI Emoji, NotoColorEmoji, Segoe UI Symbol, Android Emoji, EmojiSymbols" size="3" style="font-family: Calibri, Helvetica, sans-serif, serif, EmojiFont;" class="">The
meeting will be held </font><font size="3" style="font-family: Calibri, Helvetica, sans-serif, serif, EmojiFont;" class="">in</font><font face="Calibri, Helvetica, sans-serif, Helvetica, EmojiFont, Apple Color Emoji, Segoe UI Emoji, NotoColorEmoji, Segoe UI Symbol, Android Emoji, EmojiSymbols" size="3" class=""><font face="Calibri, Helvetica, sans-serif, serif, EmojiFont" class=""> <b class="">hybrid </b></font><b class="">mode</b></font><font size="3" face="Calibri, Helvetica, sans-serif, serif, EmojiFont" class=""> at
the </font><span style="font-family: Calibri, sans-serif; font-size: 14.666666984558105px;" class=""><b class="">Albano 3:6228 - Mega </b></span><font face="Calibri, sans-serif" class=""><span style="font-size: 14.666666984558105px;" class=""><b class="">room</b>. </span></font></div>
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<font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="2" color="#212121" class=""><span style="font-size: 15px;" class=""><font face="Calibri,Helvetica,sans-serif,Helvetica,EmojiFont,Apple Color Emoji,Segoe UI Emoji,NotoColorEmoji,Segoe UI Symbol,Android Emoji,EmojiSymbols" size="3" color="black" class=""><span lang="en-US" style="font-size: 12pt;" class=""><b class="">To
join remotely via zoom:</b></span></font></span></font></div>
<div style="font-family: Calibri, Helvetica, sans-serif, Helvetica, EmojiFont, "Apple Color Emoji", "Segoe UI Emoji", NotoColorEmoji, "Segoe UI Symbol", "Android Emoji", EmojiSymbols; font-size: 12pt; margin-top: 0px; margin-bottom: 0px;" class="">
<font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="2" color="#212121" class=""><span style="font-size: 15px;" class=""><font face="Calibri,Helvetica,sans-serif,Helvetica,EmojiFont,Apple Color Emoji,Segoe UI Emoji,NotoColorEmoji,Segoe UI Symbol,Android Emoji,EmojiSymbols" size="2" color="black" class=""><span lang="en-US" style="font-size: 16px;" class=""><a href="https://stockholmuniversity.zoom.us/j/65883589027?pwd=RGxJOUVQWmNtMlZFMUIwaHRabkExdz09" class="">https://stockholmuniversity.zoom.us/j/65883589027?pwd=RGxJOUVQWmNtMlZFMUIwaHRabkExdz09</a></span></font></span></font></div>
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<font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="2" color="#212121" class=""><span style="font-size: 15px;" class=""><font face="Calibri,Helvetica,sans-serif,Helvetica,EmojiFont,Apple Color Emoji,Segoe UI Emoji,NotoColorEmoji,Segoe UI Symbol,Android Emoji,EmojiSymbols" size="2" color="black" class=""><span lang="en-US" style="font-size: 16px;" class=""><br class="">
</span></font></span></font></div>
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<font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="2" color="#212121" class=""><span style="font-size: 15px;" class=""><font face="Calibri,Helvetica,sans-serif,Helvetica,EmojiFont,Apple Color Emoji,Segoe UI Emoji,NotoColorEmoji,Segoe UI Symbol,Android Emoji,EmojiSymbols" size="3" color="black" class=""><span lang="en-US" style="font-size: 12pt;" class=""><b class="">Meeting
ID:</b></span></font><font face="Calibri,Helvetica,sans-serif,Helvetica,EmojiFont,Apple Color Emoji,Segoe UI Emoji,NotoColorEmoji,Segoe UI Symbol,Android Emoji,EmojiSymbols" size="3" color="black" class=""><span lang="en-US" style="font-size: 12pt;" class=""> 658
8358 9027</span></font></span></font></div>
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<font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="2" color="#212121" class=""><span style="font-size: 15px;" class=""><font face="Calibri,Helvetica,sans-serif,Helvetica,EmojiFont,Apple Color Emoji,Segoe UI Emoji,NotoColorEmoji,Segoe UI Symbol,Android Emoji,EmojiSymbols" size="3" color="black" class=""><span lang="en-US" style="font-size: 12pt;" class=""><b class="">Title: </b></span></font></span></font></div>
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<span style="font-size: 12pt; font-family: Calibri, Helvetica, sans-serif;" class="">Power sources of hydrogen-rich superluminous supernovae</span></div>
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<span style="font-size: 12pt; font-family: Arial, sans-serif, serif, EmojiFont; color: black;" class=""> </span></div>
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<font size="2" style="font-family: Calibri, sans-serif, serif, EmojiFont;" class=""><span style="font-size: 11pt;" class=""><font size="3" color="black" style="font-family: Arial, sans-serif, serif, EmojiFont;" class=""><span style="font-size: 12pt;" class=""><b class="">Abstract:</b></span></font></span></font></div>
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<span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Calibri, Helvetica, sans-serif; font-size: 16px;" class="">Superluminous supernovae (SLSNe), with their often-extreme luminosity compared with the typical core-collapse supernovae (CCSNe)
of massive stars, cannot be explained with the power sources typical to their lower-luminosity counterparts. Analogously to CCSNe, SLSNe are divided into hydrogen-poor (type I) and hydrogen-rich (type II). Most hydrogen-rich SLSNe are clearly powered by interaction
with a dense circumstellar medium (CSM) and have spectra with strong narrow emission lines, while hydrogen-poor ones are thought to be powered by the spin-down of a magnetar born in the explosion. In rare cases, SLSNe II with broad emission lines but no narrow
lines are found; the power sources of such SNe have been ambiguous, with both magnetars and CSM interaction as possible explanations, but only a few are known in the literature. I present a study based on 14 SLSNe II without narrow lines, the largest such
sample to date, discovered and/or followed up by the Zwicky Transient Facility between 2018 and 2020. We have examined the light curves, spectra and host galaxies of these SLSNe and fitted light curve models to them. While light curve models have trouble distinguishing
between magnetars and CSM, other signs point toward interaction being the dominant powering mechanism of SLSNe II. The most luminous ones, however, may need another power source as well.</span></div>
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<div style="margin-top: 0px; margin-bottom: 0px;" class=""><font size="3" class="">Kind regards,</font></div>
<div style="margin-top: 0px; margin-bottom: 0px;" class=""><font size="3" class=""><br class="">
</font></div>
<div style="margin-top: 0px; margin-bottom: 0px;" class=""><font size="3" class="">Note: We welcome our new organiser </font><span style="font-size: medium; orphans: 2; widows: 2; background-color: rgb(255, 255, 255);" class="">Haakon Andresen</span></div>
<div style="margin-top: 0px; margin-bottom: 0px;" class=""><font size="3" class=""><br class="">
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<div style="margin-top: 0px; margin-bottom: 0px;" class=""><font size="3" class="">Ana Sagués Carracedo & Davide Gizzi & </font><span style="font-size: medium; orphans: 2; widows: 2; background-color: rgb(255, 255, 255);" class="">Haakon Andresen</span></div>
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