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Dear colleagues, </div>
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<span role="button" class="contextualExtensionHighlight ms-font-color-themePrimary ms-border-color-themePrimary ident_110_217" tabindex="0">our next EO meeting will take place this Thursday </span><b><span role="button" class="contextualExtensionHighlight ms-font-color-themePrimary ms-border-color-themePrimary ident_110_217" tabindex="0">Feb
28</span></b><span role="button" class="contextualExtensionHighlight ms-font-color-themePrimary ms-border-color-themePrimary ident_110_217" tabindex="0"> at </span><b><span role="button" class="contextualExtensionHighlight ms-font-color-themePrimary ms-border-color-themePrimary ident_110_217" tabindex="0">13:15</span></b><span role="button" class="contextualExtensionHighlight ms-font-color-themePrimary ms-border-color-themePrimary ident_110_217" tabindex="0"> in
the KTH meeting room on the 5th floor.</span> </div>
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<div><span style="font-family: Calibri, Helvetica, sans-serif, EmojiFont, "Apple Color Emoji", "Segoe UI Emoji", NotoColorEmoji, "Segoe UI Symbol", "Android Emoji", EmojiSymbols; font-size: 16px;"><b>Dr Dan Perley</b> visiting from
<b>LJMU</b> will present us the following talk</span><br>
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<p><span style="font-size: 12pt; color: rgb(33, 33, 33); font-family: wf_segoe-ui_normal, "Segoe UI", "Segoe WP", Tahoma, Arial, sans-serif, serif, EmojiFont;">Multiwavelength Observations of the Extreme Transient AT2018cow</span><br>
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<p><font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="1" color="#212121"><span style="font-size: 12pt;">The bright, luminous, and fast multiwavelength transient AT2018cow </span></font><font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="1" color="#212121"><span style="font-size: 12pt;">displayed
unprecedented behavior at almost every waveband: a </span></font><font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="1" color="#212121"><span style="font-size: 12pt;">fast-evolving UV/optical counterpart that maintains
an extremely hot </span></font><font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="1" color="#212121"><span style="font-size: 12pt;">photospheric temperature over its entire evolution, an </span></font><font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="1" color="#212121"><span style="font-size: 12pt;">erratically-fluctuating
luminous X-ray counterpart, and a heavily </span></font><font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="1" color="#212121"><span style="font-size: 12pt;">self-absorbed </span></font><font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="1" color="#212121"><span style="font-size: 12pt;">radio/submillimeter
counterpart. We present a comprehensive set </span></font><font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="1" color="#212121"><span style="font-size: 12pt;">of photometric and spectroscopic observations of this
transient from </span></font><font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="1" color="#212121"><span style="font-size: 12pt;">groundbased observatories spanning four continents and from space, </span></font><font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="1" color="#212121"><span style="font-size: 12pt;">including
multiwavelength observations from Swift, NuSTAR, Astrosat, </span></font><font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="1" color="#212121"><span style="font-size: 12pt;">SMA, and ALMA. We consider both supernova
and intermediate-mass black </span></font><font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="1" color="#212121"><span style="font-size: 12pt;">hole tidal disruption event interpretations for its origin, although
no </span></font><font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="1" color="#212121"><span style="font-size: 12pt;">simple theoretical model can explain the full set of observations. </span></font><font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="1" color="#212121"><span style="font-size: 12pt;">Transients
similar to AT2018cow are probably not rare in the universe: </span></font><font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="1" color="#212121"><span style="font-size: 12pt;">we are on the alert for more such objects
within ZTF, and anticipate </span></font><font face="wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif,serif,EmojiFont" size="1" color="#212121"><span style="font-size: 12pt;">that they will be detected in large numbers by LSST in the coming decade.</span></font><br>
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<p style="font-size:16px; font-family:Calibri,Helvetica,sans-serif">---------------------------------</p>
<p style="font-size:16px; font-family:Calibri,Helvetica,sans-serif">André da Silva Schneider<br>
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<p style="font-size:16px; font-family:Calibri,Helvetica,sans-serif"><span style="font-size:10pt; font-family:Calibri,Helvetica,sans-serif,serif,EmojiFont">Department of Astronomy</span><br>
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<p style="font-size:16px; font-family:Calibri,Helvetica,sans-serif"><span style="font-family:Calibri,Helvetica,sans-serif,serif,EmojiFont"><span style="font-size:10pt">Stockholm University</span></span></p>
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