{"product_id":"shelyak-op0094","title":"Shelyak Prism 3.8° for the Star Analyser","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e3.8° prism angle precisely calculated for the Star Analyser\u003c\/li\u003e\n\u003cli\u003eImproves spectral resolution by approximately 20%\u003c\/li\u003e\n\u003cli\u003eAchieves a resolving power of R~130\u003c\/li\u003e\n\u003cli\u003eCorrects optical coma inherent in converging beam setups\u003c\/li\u003e\n\u003cli\u003eOptimized for advanced applications like nova and supernova characterization\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003ePrism 3.8° for the Star Analyser\u003c\/h2\u003e\n\u003cp\u003eThe Shelyak Prism 3.8° for the Star Analyser is an optical enhancement designed to increase its resolving power by approximately 20%. This accessory corrects for coma inherent in the Star Analyser's simple design, pushing its performance to a resolving power of R~130. By adding this 3.8° prism, you can extract more detailed spectral data from your existing setup.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eCorrect Coma and Boost Resolution by 20% to R~130\u003c\/h3\u003e\n\u003cp\u003eThe Star Analyser's effectiveness comes from its simplicity—placing a diffraction grating directly into a telescope's converging light path. However, this introduces optical coma, which can soften spectral lines. The 3.8° Prism is specifically calculated to counteract this aberration, resulting in a sharper spectrum and an approximate 20% improvement in resolving power, achieving R~130.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eIs the 3.8° Prism Necessary for Your Spectroscopy?\u003c\/h3\u003e\n\u003cp\u003eThis prism is not a requirement for everyone. If you are using the Star Analyser to explore the basics of spectroscopy, the standard configuration is more than sufficient. However, if your goal is to push the instrument to its analytical limits for scientific contribution—such as characterizing the spectral evolution of novae or supernovae—this 3.8° prism is an essential upgrade.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main purpose of the Prism 3.8° for the Star Analyser?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary purpose of the 3.8° Prism is to improve the optical quality and resolution of spectra produced by a Star Analyser grating. It specifically corrects for \u003cstrong\u003ecoma\u003c\/strong\u003e, an aberration introduced when the grating is placed in a converging telescope beam, boosting resolution by about \u003cstrong\u003e20% to R~130\u003c\/strong\u003e.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the 3.8° Prism for the Star Analyser improve resolution?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe prism works by pre-correcting the light path before it reaches the diffraction grating. Its \u003cstrong\u003e3.8° wedge angle\u003c\/strong\u003e is precisely calculated to cancel out the coma that the simple, in-beam placement of the Star Analyser would otherwise create. This results in sharper, better-defined spectral lines and therefore higher effective resolution.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need this 3.8° Prism if I'm just starting with spectroscopy?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this prism is generally not necessary for beginners. The standard Star Analyser is an excellent tool for learning and discovering spectroscopy. This 3.8° prism is an upgrade for users who want to push the Star Analyser to its maximum performance for more demanding applications, like pro-am collaborations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the 3.8° Prism to study the spectrum of a bright supernova like SN 2023ixf?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, this is an ideal application. Characterizing novae and supernovae is a key use case for this prism. The increased resolution to \u003cstrong\u003eR~130\u003c\/strong\u003e allows for better identification and monitoring of spectral features as the event evolves, providing more valuable scientific data than the Star Analyser could achieve on its own.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of optical aberration does the Prism 3.8° correct in my f\/8 SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe prism is designed to correct for \u003cstrong\u003ecoma\u003c\/strong\u003e that is introduced by the Star Analyser itself, not the telescope. When you place the grating in the converging f\/8 light cone of your SCT, coma is created. The 3.8° Prism is engineered to minimize this specific aberration, leading to a cleaner spectrum regardless of your telescope's native optical quality.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the 3.8° Prism for the Star Analyser change how I process my spectra?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe prism does not fundamentally change the data acquisition or processing workflow. You will still capture and calibrate your spectra using the same software (like Demetra). The primary difference will be in the final result: you will start with a sharper raw image, allowing for a more precise and higher-resolution final spectral profile.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Shelyak_Star_Analyser_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eShelyak Star Analyser Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/shelyak-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eShelyak 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Shelyak","offers":[{"title":"Default Title","offer_id":52943034614045,"sku":"SHK-OP0094","price":82.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Shelyak-Prism-3-8-for-the-Star-Analyser-1_4033f785-10e6-4816-acc7-23ef1ad0c1cf.jpg?v=1789616029","url":"https:\/\/davidastro.com\/fr-us\/products\/shelyak-op0094","provider":"David Astro","version":"1.0","type":"link"}