{"id":6520,"date":"2026-08-19T13:00:15","date_gmt":"2026-08-19T13:00:15","guid":{"rendered":"https:\/\/www.astri.inaf.it\/?p=6520"},"modified":"2026-08-19T15:16:00","modified_gmt":"2026-08-19T15:16:00","slug":"astri-horn-is-back-in-the-spotlight","status":"publish","type":"post","link":"https:\/\/www.astri.inaf.it\/index.php\/astri-horn-is-back-in-the-spotlight\/2026\/?lang=en","title":{"rendered":"ASTRI-Horn is back in the spotlight"},"content":{"rendered":"\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-mq8498r3-1d7a7d0edef4df5bc5b1fe37cf7e2854\">\n#top .av-special-heading.av-mq8498r3-1d7a7d0edef4df5bc5b1fe37cf7e2854{\npadding-bottom:10px;\n}\nbody .av-special-heading.av-mq8498r3-1d7a7d0edef4df5bc5b1fe37cf7e2854 .av-special-heading-tag .heading-char{\nfont-size:25px;\n}\n.av-special-heading.av-mq8498r3-1d7a7d0edef4df5bc5b1fe37cf7e2854 .av-subheading{\nfont-size:15px;\n}\n<\/style>\n<div  class='av-special-heading av-mq8498r3-1d7a7d0edef4df5bc5b1fe37cf7e2854 av-special-heading-h3  avia-builder-el-0  el_before_av_textblock  avia-builder-el-first '><h3 class='av-special-heading-tag '  itemprop=\"headline\"  >ASTRI-Horn is back in the spotlight <\/h3><div class=\"special-heading-border\"><div class=\"special-heading-inner-border\"><\/div><\/div><\/div>\n<section  class='av_textblock_section av-mq85q47y-7eb74d3dabd006628bea0363470eb7cc '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><p><em>From Editorial Team<\/em><\/p>\n<\/div><\/section>\n<div  class='flex_column av-3ognnp-f115064f93c47ca6d53a1b3267f59311 av_two_third  avia-builder-el-2  el_after_av_textblock  el_before_av_one_fourth  first flex_column_div  column-top-margin'     ><section  class='av_textblock_section av-mq84e1if-23761019d2af4adfe477efa7190bd3c9 '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><p><b>After a major upgrade and calibration phase, the ASTRI-Horn prototype on Mount Etna has proven to be a highly successful instrument. In addition to the scientific results achieved, the telescope has confirmed the validity of the technologies employed, which are also used by the ASTRI Mini-Array and the SST telescopes of the Cherenkov Telescope Array Observatory (CTAO). It will soon be used as a testbed for the study of volcanoes through Cherenkov muon observations.\u00a0<\/b><\/p>\n<p>The ASTRI-Horn telescope, built as part of the ASTRI project at the INAF &#8220;M.C. Fracastoro&#8221; observing station in Serra La Nave, on the slopes of Mount Etna (Sicily, Italy), is the first Cherenkov telescope (IACT) to implement the innovative dual-mirror Schwarzschild-Couder optical configuration, coupled with a compact optical camera based on silicon-based sensors (SiPM) developed by INAF. The telescope was named after Guido Horn D\u2019Arturo, the Italian astronomer, father of tessellated mirror technology for astronomical telescopes, to whom the recent conference \u201c<a href=\"https:\/\/indico.ict.inaf.it\/event\/3198\/\" target=\"_blank\" rel=\"noopener\">Mosaic Telescopes &#8211; Technology and Science<\/a>\u201d (Bologna, January 26-27, 2026) was dedicated.<\/p>\n<p>Between 2020 and 2022, the facility underwent a major overhaul and upgrade. A recent study, published in the journal <i>Publications of the Astronomical Society of the Pacific<\/i> and led by INAF, details the improvements made. These improvements included the use of new reflective optical coatings (optimized to capture Cherenkov light while reducing background noise) on the primary mirror segments, camera enhancements, and a revamp of the control and data acquisition software, as well as refinements to the Monte Carlo simulations and the first tests of machine learning algorithms for shower analysis.<\/p>\n<\/div><\/section><\/div>\n<div  class='flex_column av-321h0l-224518f7cd7976d2571e686a31eaf864 av_one_fourth  avia-builder-el-4  el_after_av_two_third  el_before_av_textblock  flex_column_div  column-top-margin'     ><style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-mq85p2au-a388703f44c64baf2f9768a24a6b4152\">\n.avia-image-container.av-mq85p2au-a388703f44c64baf2f9768a24a6b4152 img.avia_image{\nbox-shadow:none;\n}\n.avia-image-container.av-mq85p2au-a388703f44c64baf2f9768a24a6b4152 .av-image-caption-overlay-center{\ncolor:#ffffff;\n}\n<\/style>\n<div  class='avia-image-container av-mq85p2au-a388703f44c64baf2f9768a24a6b4152 av-styling- avia-align-center  avia-builder-el-5  avia-builder-el-no-sibling '   itemprop=\"image\" itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/ImageObject\" ><div class=\"avia-image-container-inner\"><div class=\"avia-image-overlay-wrap\"><img decoding=\"async\" fetchpriority=\"high\" class='wp-image-6508 avia-img-lazy-loading-not-6508 avia_image ' src=\"https:\/\/www.astri.inaf.it\/wp-content\/uploads\/2026\/08\/paspae8478f2_hr.jpg\" alt='Dall&#039;articolo di G. Leto et al. 2026: il telescopio ASTRI-Horn mostra il nuovo coating dei tasselli dello specchio principale' title='Astri-Horn-nuovo-coating'  height=\"512\" width=\"385\"  itemprop=\"thumbnailUrl\"  \/><\/div><\/div><\/div><\/div>\n<section  class='av_textblock_section av-mq85r07r-83f362a397e5e0388c05118829d58e17 '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><p>To verify its new performance, ASTRI-Horn observed the &#8220;standard candle&#8221; of gamma-ray astrophysics: the Crab Nebula.<\/p>\n<p>The observations, conducted between late 2022 and early 2023, revealed the source with good significance in approximately 20 hours of selected data. The analysis also allowed the nebula&#8217;s energy spectrum to be reconstructed up to 10 TeV, a result in excellent agreement with previous measurements made by networks of Cherenkov telescopes such as MAGIC and H.E.S.S.<\/p>\n<div id=\"attachment_6511\" style=\"width: 760px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-6511\" class=\"wp-image-6510\" src=\"https:\/\/www.astri.inaf.it\/wp-content\/uploads\/2026\/08\/CrabNebulaDetectionASTRI-Horn-hr.jpg\" alt=\"Due pannelli : a sinistra la\" width=\"750\" height=\"335\" \/><p id=\"caption-attachment-6511\" class=\"wp-caption-text\">Adapted from G. Leto et al. paper: the Crab Nebula observed by\u00a0 ASTRI-Horn<\/p><\/div>\n<p><b>A fundamental testbed for the ASTRI Mini-Array and the CTAO SSTs\u00a0<\/b><\/p>\n<p>The results obtained are not only a milestone for this telescope alone, but also represent a key point for the future of very high-energy astrophysics. ASTRI-Horn&#8217;s observing campaign has enabled the entire data acquisition, simulation, and analysis chain to be verified.<\/p>\n<p>These technologies, developed with significant Italian contribution, form the construction and operational basis of the ASTRI Mini-Array dual-mirror telescopes, composed of nine telescopes currently under construction at the Teide Observatory in Tenerife (Canary Islands, Spain), and of the future small-scale telescopes (SSTs) for the southern site of the Cherenkov Telescope Array Observatory (CTAO) in Chile.<\/p>\n<p>Furthermore, the experience gained on Etna in extreme environmental conditions\u2014including fumes, volcanic ash, and large temperature fluctuations\u2014has provided valuable lessons to ensure future telescopes have unprecedented durability and reliability. This experience will be further enhanced in the coming months, thanks to the European PN RIC program <i>CTA++<\/i>, with the refinement of volcano observation with muon showers. ASTRI-Horn thus confirms itself not only as an excellent technological prototype, but also as a mature scientific instrument, which, thanks to its modularity, can easily be reproduced on the larger scale of the next generation of very high-energy gamma-ray telescopes.<\/p>\n<ul>\n<li style=\"list-style-type: none;\">\n<ul>\n<li>The results are published by <i>Publications of the Astronomical Society of the Pacific <\/i>in the paper: &#8220;<a href=\"https:\/\/iopscience.iop.org\/article\/10.1088\/1538-3873\/ae8478\" target=\"_blank\" rel=\"noopener\">The ASTRI-Horn Cherenkov Telescope: Technical Assessment and Calibrations Following its Refurbishment for the ASTRI Mini-Array and CTA-SST Pathfinder<\/a>&#8221; (G. Leto et al., 2026 PASP 138 085001 &#8211; <b>DOI<\/b> 10.1088\/1538-3873\/ae8478<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/div><\/section>\n","protected":false},"excerpt":{"rendered":"<p>After a major upgrade and calibration phase, the ASTRI-Horn prototype on Mount Etna has proven to be a highly successful instrument. In addition to the scientific results achieved, the telescope has confirmed the validity of the technologies employed, which are also used by the ASTRI Mini-Array and the SST telescopes of the Cherenkov Telescope Array Observatory (CTAO). It will soon be used as a testbed for the study of volcanoes through Cherenkov muon observations.<\/p>\n","protected":false},"author":3,"featured_media":6541,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[55],"tags":[80,100,102,98,104,105,103],"class_list":["post-6520","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news-en","tag-astri-mini-array-en-2","tag-astri-horn-en","tag-ctao-en","tag-iact-en","tag-piccoli-telescopi-en","tag-prototipo-en","tag-sst-en"],"_links":{"self":[{"href":"https:\/\/www.astri.inaf.it\/index.php\/wp-json\/wp\/v2\/posts\/6520","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.astri.inaf.it\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.astri.inaf.it\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.astri.inaf.it\/index.php\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.astri.inaf.it\/index.php\/wp-json\/wp\/v2\/comments?post=6520"}],"version-history":[{"count":24,"href":"https:\/\/www.astri.inaf.it\/index.php\/wp-json\/wp\/v2\/posts\/6520\/revisions"}],"predecessor-version":[{"id":6559,"href":"https:\/\/www.astri.inaf.it\/index.php\/wp-json\/wp\/v2\/posts\/6520\/revisions\/6559"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.astri.inaf.it\/index.php\/wp-json\/wp\/v2\/media\/6541"}],"wp:attachment":[{"href":"https:\/\/www.astri.inaf.it\/index.php\/wp-json\/wp\/v2\/media?parent=6520"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.astri.inaf.it\/index.php\/wp-json\/wp\/v2\/categories?post=6520"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.astri.inaf.it\/index.php\/wp-json\/wp\/v2\/tags?post=6520"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}