SN 2025qpk: A Photometric and Spectroscopic Case for Type II-P Reclassification

SN 2025qpk: A Photometric and Spectroscopic Case for Type II-P Reclassification | 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 SN 2025qpk: A Photometric and Spectroscopic Case for Type II-P Reclassification Caroline Escobedo, Dane Hansen, Satya Iyer, Gavin Warnakulasooriya This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8633877/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Studying supernovae provides numerous insights into the nature of the universe, revealing distances to galaxies and the way that heavy elements first formed. On July 7th, 2025, supernova (SN) 2025qpk was discovered in the galaxy UGC 11622, and later classified as a Type Ia supernova. Our team utilized photometry and spectroscopy techniques to gather data on SN 2025qpk. Over 13 days, we performed Sloan g and r imaging of SN 2025qpk a total of 7 times. We collected images in-person using a 0.4-meter f/8.9 reflector telescope at the Leitner Family Observatory and Planetarium at Yale University. We also collected imaging remotely with the 0.61-meter f/6.5 reflector telescope at the Sierra Remote Observatory in Auberry, California. Our data was test-fit with models of various SN types, and found the Type II-P model to fit best, with a χ2 value of 2.9307. This evidence counters 2025qpk’s previous classification of Type Ia. Our spectroscopy shows hints of absorption typical of a Type II-P supernova, providing further evidence for our reclassification. Our findings provide a case for further analysis of SN 2025qpk, whose classification and characteristics remain intriguing. Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-8633877","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":581779023,"identity":"304130d7-a949-4691-a566-29a4d6a82591","order_by":0,"name":"Caroline Escobedo","email":"","orcid":"","institution":"West Aurora High School","correspondingAuthor":false,"prefix":"","firstName":"Caroline","middleName":"","lastName":"Escobedo","suffix":""},{"id":581779024,"identity":"2db5ca41-407e-41b7-b7f6-6e9efba6fbdc","order_by":1,"name":"Dane Hansen","email":"","orcid":"","institution":"Menlo-Atherton High School","correspondingAuthor":false,"prefix":"","firstName":"Dane","middleName":"","lastName":"Hansen","suffix":""},{"id":581779025,"identity":"8764ac00-4999-4e0e-a6b4-8d6dcfc090b3","order_by":2,"name":"Satya Iyer","email":"","orcid":"","institution":"Dowling Catholic High School","correspondingAuthor":false,"prefix":"","firstName":"Satya","middleName":"","lastName":"Iyer","suffix":""},{"id":581779026,"identity":"bd8b65a5-32e2-473c-a8ca-d731d1f7d9b8","order_by":3,"name":"Gavin Warnakulasooriya","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA8UlEQVRIiWNgGAWjYJCCAxCK+eCDD0CKjZ14LWzJhjNAFDPxlvGYSfOAbSOgTt79jOHhwja7fHP2M2bSNr+2yfMxMzB++JiDW4vhmRyDwzPbki139qQVW+f23TZsY2Zglpy5DY+WhrSEw7zbmA0MDiRvvJ3bc5sRqIWNmReflv5nIC31BgbnHxhIW/bctieoRV4i+QBQy2EDgxspRtIMP24nEtRiIPEYqOXfcaCWZ8mGvQ23k9uYGZvx+kW+P7H5M8+ZaqDDkg8++PHntu389uaDHz7is+UAMo+xDUw24FYPsgVV+g9exaNgFIyCUTBCAQB6RlRHlu/IIQAAAABJRU5ErkJggg==","orcid":"","institution":"Franklin High School","correspondingAuthor":true,"prefix":"","firstName":"Gavin","middleName":"","lastName":"Warnakulasooriya","suffix":""}],"badges":[],"createdAt":"2026-01-19 00:08:14","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8633877/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8633877/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":101398550,"identity":"9ca9d99f-0138-407d-a06c-4361573a63f3","added_by":"auto","created_at":"2026-01-29 09:42:15","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":709170,"visible":true,"origin":"","legend":"","description":"","filename":"Team1PaperSN2025qpk1.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8633877/v1_covered_56390f6e-ea47-4435-b1e8-bc73efd88d70.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"SN 2025qpk: A Photometric and Spectroscopic Case for Type II-P Reclassification","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-8633877/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8633877/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Studying supernovae provides numerous insights into the nature of the universe, revealing distances to galaxies and the way that heavy elements first formed. On July 7th, 2025, supernova (SN) 2025qpk was discovered in the galaxy UGC 11622, and later classified as a Type Ia supernova. Our team utilized photometry and spectroscopy techniques to gather data on SN 2025qpk. Over 13 days, we performed Sloan g and r imaging of SN 2025qpk a total of 7 times. We collected images in-person using a 0.4-meter f/8.9 reflector telescope at the Leitner Family Observatory and Planetarium at Yale University. We also collected imaging remotely with the 0.61-meter f/6.5 reflector telescope at the Sierra Remote Observatory in Auberry, California. Our data was test-fit with models of various SN types, and found the Type II-P model to fit best, with a χ2 value of 2.9307. This evidence counters 2025qpk’s previous classification of Type Ia. Our spectroscopy shows hints of absorption typical of a Type II-P supernova, providing further evidence for our reclassification. 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