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<p><span style="font-family: Helvetica; font-size: 18px;">Dear all,</span><br style="font-family: Helvetica; font-size: 18px;">
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<span style="font-family: Helvetica; font-size: 18px;">This is a reminder for the departmental seminar today at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (</span><a class="moz-txt-link-freetext" href="https://stockholmuniversity.zoom.us/j/62211269644?pwd=K0J2eVVMa3pTa1JVN2lyRUJPR3Rjdz09" style="font-family: Helvetica; font-size: 18px;" id="LPlnk989296" previewremoved="true">https://stockholmuniversity.zoom.us/j/62211269644?pwd=K0J2eVVMa3pTa1JVN2lyRUJPR3Rjdz09</a><span style="font-family: Helvetica; font-size: 18px;">).</span><br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">___________________</span><br style="font-family: Helvetica; font-size: 18px;">
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<span style="font-family: Helvetica; font-size: 18px;">Speaker: Khaled Al Moulla (University of Geneva)</span><br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">Title: Roadblocks to Detect Earth-like Exoplanets: Solar-type Activity in Radial Velocities</span><br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">Event: </span><a class="moz-txt-link-freetext" href="https://indico.fysik.su.se/e/khaled_al_moulla" style="font-family: Helvetica; font-size: 18px;" id="LPlnk836837" previewremoved="true">https://indico.fysik.su.se/e/khaled_al_moulla</a><br style="font-family: Helvetica; font-size: 18px;">
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<span style="font-family: Helvetica; font-size: 18px;">Abstract:</span><br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">The radial velocity (RV) technique for detecting exoplanets has in recent years been limited in its applicability to search for Earth-mass planets due to their small semi-amplitudes relative to the intrinsic
variability of their host stars. In this talk, I will present the signatures of stellar activity in high-resolution optical and near-infrared (NIR) spectral time series of the Sun and solar-type stars, observed with the HARPS, HARPS-N and NIRPS spectrographs.
I will talk about a novel, physically motivated method of RV extraction based on the average formation temperature of spectral segments, in order to demonstrate the differential effect of stellar activity signals as a function of photospheric depth, enabling
the separation of temperature-dependent stellar activity from constant Keplerian signals. Additionally, I compare the chromaticity of unsigned magnetic field proxies in the optical versus NIR to evaluate their usefulness as activity indicators with which the
stellar signals can be mitigated.</span><br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">___________________</span><br style="font-family: Helvetica; font-size: 18px;">
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<span style="font-family: Helvetica; font-size: 18px;">We look forward to seeing many of you there. Thanks!</span><br style="font-family: Helvetica; font-size: 18px;">
<br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">Adur, Adélaïde, and Sanja</span><br style="font-family: Helvetica; font-size: 18px;">
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<span style="font-family: Helvetica; font-size: 18px;">Upcoming Events:</span><br style="font-family: Helvetica; font-size: 18px;">
<br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">2024-03-29 ** No seminar ** Good Friday</span><br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">2024-04-05 Simon Ringqvist</span><br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">2024-04-10 Yutong He (**Seminar on WEDNESDAY**)</span><br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">2024-04-12 Alex Riley</span><br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">2024-04-19 Arthur Choplin</span><br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">2024-04-26 Dominique Petit</span><br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">2024-05-03 Gang Li</span><br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">2024-05-08 Ivo (**Seminar on WEDNESDAY**)</span><br style="font-family: Helvetica; font-size: 18px;">
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<span style="font-family: Helvetica; font-size: 18px;">You can subscribe to the seminars calendar in:</span><br style="font-family: Helvetica; font-size: 18px;">
<a class="moz-txt-link-freetext" href="https://ttt.astro.su.se/ical/astro-seminars.ics" style="font-family: Helvetica; font-size: 18px;" id="LPlnk814116">https://ttt.astro.su.se/ical/astro-seminars.ics</a><br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">(Please note that calendar can be subject to updates)</span><br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">___________________</span><br style="font-family: Helvetica; font-size: 18px;">
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<span style="font-family: Helvetica; font-size: 18px;">Join Zoom Meeting:</span><br style="font-family: Helvetica; font-size: 18px;">
<a class="moz-txt-link-freetext" href="https://stockholmuniversity.zoom.us/j/62211269644?pwd=K0J2eVVMa3pTa1JVN2lyRUJPR3Rjdz09" style="font-family: Helvetica; font-size: 18px;">https://stockholmuniversity.zoom.us/j/62211269644?pwd=K0J2eVVMa3pTa1JVN2lyRUJPR3Rjdz09</a><br style="font-family: Helvetica; font-size: 18px;">
<span style="font-family: Helvetica; font-size: 18px;">Meeting ID: 622 1126 9644</span><br>
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