Seeing at Timau National Observatory Based on ERA5 Dataset

Seeing at Timau National Observatory Based on ERA5 Dataset | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Seeing at Timau National Observatory Based on ERA5 Dataset Rhorom Priyatikanto, Clara Y. Yatini, Gerhana P. Putri, Ishfahani Rusyda, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7560729/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 22 Apr, 2026 Read the published version in Experimental Astronomy → Version 1 posted 7 You are reading this latest preprint version Abstract Understanding the seeing conditions is crucial for astronomical observations using a ground-based telescope. This study analyzes long-term atmospheric data (2002–2021) from the ERA5 dataset to assess the seeing conditions at the new Timau National Observatory in Indonesia, which hosts a 3.8-meter optical telescope. While the ERA5 dataset shows remarkable agreement with radiosonde data for temperature and wind speed, it tends to underestimate seeing at Eltari Airport, Kupang. Despite this discrepancy, the ERA5 data suggest a median seeing of 0.79 arcseconds at Timau, with optimal seeing conditions in March and December and greater variability during the May to September dry season. These findings are crucial for the planning and operation of the observatory, which requires excellent seeing conditions for its three-band optical imager and a near-infrared camera. Although the seeing at Timau is not as good as some other observatories, the conditions at Timau make it an observatory that has good prospects for equatorial regions. statistical site testing astronomical seeing Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 22 Apr, 2026 Read the published version in Experimental Astronomy → Version 1 posted Editorial decision: Revision requested 05 Mar, 2026 Reviews received at journal 05 Mar, 2026 Reviewers agreed at journal 07 Feb, 2026 Reviewers invited by journal 29 Sep, 2025 Editor assigned by journal 09 Sep, 2025 Submission checks completed at journal 09 Sep, 2025 First submitted to journal 08 Sep, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7560729","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":527125905,"identity":"3213247f-79a5-438b-8d55-80863c335692","order_by":0,"name":"Rhorom Priyatikanto","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAwElEQVRIiWNgGAWjYDACCSBOMJCQM2BgbAALsDEkEKHlQ4WFMWlaGGecqUjcgBAioMV8dvOxz7xtEunbpQ+3PWD4ZcPAx05Ai8ydY8mzgVpyd/Ylthsw9qUxsPE8IOAuiRxjZpCWDWcY2yQYew4zsEkQsAWmJd2AJC1A70skgLUw/CBKS1oyMJAlDHf2ALUkNqTxEOGX5MPAqKyTN+dhfybx4Y+NnHw7AVtQQWIbAw8p6kHgD6kaRsEoGAWjYCQAAKhjOrdk313yAAAAAElFTkSuQmCC","orcid":"","institution":"National Research and Innovation Agency","correspondingAuthor":true,"prefix":"","firstName":"Rhorom","middleName":"","lastName":"Priyatikanto","suffix":""},{"id":527125906,"identity":"b82fb37b-f8c8-490e-a911-57d85eafad53","order_by":1,"name":"Clara Y. 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