{"id":2198,"date":"2024-06-03T07:05:00","date_gmt":"2024-06-03T06:05:00","guid":{"rendered":"https:\/\/pepsi.aip.de\/?p=2198"},"modified":"2024-09-02T07:37:18","modified_gmt":"2024-09-02T06:37:18","slug":"the-pepsi-exoplanet-transit-survey-pets-v-new-na-d-transmission-spectra-indicate-a-quieter-atmosphere-on-hd-189733b","status":"publish","type":"post","link":"https:\/\/pepsi.aip.de\/?p=2198","title":{"rendered":"The PEPSI Exoplanet Transit Survey (PETS) &#8211; V. New Na D transmission spectra indicate a quieter atmosphere on HD 189733b"},"content":{"rendered":"\n<p>Absorption lines from exoplanet atmospheres observed in transmission allow us to study atmospheric characteristics such as winds. We present a new high-resolution transit time-series of HD 189733b, acquired with the PEPSI instrument at the LBT and analyse the transmission spectrum around the Na D lines. We model the spectral signature of the RM-CLV-effect using synthetic PHOENIX spectra based on spherical LTE atmospheric models. We find an Na D absorption signature between the second and third contact but not during the ingress and egress phases, which casts doubt on the planetary origin of the signal. Presupposing a planetary origin of the signal, the results suggest a weak day-to-nightside streaming wind in the order of 0.7 km\/s and a moderate super-rotational streaming wind in the order of 3-4 km\/s, challenging claims of prevailing strong winds on HD 189733b.<\/p>\n\n\n\n<figure id=\"attachment_2200\" aria-describedby=\"caption-attachment-2200\" style=\"width: 798px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/pepsi.aip.de\/wp-content\/uploads\/2024\/09\/pets5_pic.jpeg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-2200\" src=\"https:\/\/pepsi.aip.de\/wp-content\/uploads\/2024\/09\/pets5_pic.jpeg\" alt=\"\" width=\"798\" height=\"638\" srcset=\"https:\/\/pepsi.aip.de\/wp-content\/uploads\/2024\/09\/pets5_pic.jpeg 798w, https:\/\/pepsi.aip.de\/wp-content\/uploads\/2024\/09\/pets5_pic-300x240.jpeg 300w, https:\/\/pepsi.aip.de\/wp-content\/uploads\/2024\/09\/pets5_pic-768x614.jpeg 768w\" sizes=\"auto, (max-width: 798px) 100vw, 798px\" \/><\/a><figcaption id=\"caption-attachment-2200\" class=\"wp-caption-text\">The HD 189733b transit observation. Top: Continuum signal-to-\u0002noise ratio per combined pixel (95 per cent quantile). Bottom: The RM effect. Dashed vertical lines show the contact points 1st\u20134th (cyan) and 2nd\u20133rd (purple).<\/figcaption><\/figure>\n\n\n\n<p>Read more: <a href=\"https:\/\/ui.adsabs.harvard.edu\/abs\/2024MNRAS.530.4826K\/abstract\">Keles et al. 2024, MNRAS, 530, 4826<\/a> <br \/><br \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Absorption lines from exoplanet atmospheres observed in transmission allow us to study atmospheric characteristics such as winds. We present a new high-resolution transit time-series of HD 189733b, acquired with the PEPSI instrument at the LBT and analyse the transmission spectrum around the Na D lines. We model the spectral signature of the RM-CLV-effect using synthetic &hellip; <a href=\"https:\/\/pepsi.aip.de\/?p=2198\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">The PEPSI Exoplanet Transit Survey (PETS) &#8211; V. New Na D transmission spectra indicate a quieter atmosphere on HD 189733b<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11],"tags":[],"class_list":["post-2198","post","type-post","status-publish","format-standard","hentry","category-publications"],"_links":{"self":[{"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=\/wp\/v2\/posts\/2198","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2198"}],"version-history":[{"count":3,"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=\/wp\/v2\/posts\/2198\/revisions"}],"predecessor-version":[{"id":2209,"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=\/wp\/v2\/posts\/2198\/revisions\/2209"}],"wp:attachment":[{"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2198"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2198"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2198"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}