{"product_id":"shelyak-se0288","title":"Shelyak Star’Ex 14-20-26-32 µm slit + 25 µm hole (GEN2)","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eFour selectable slit widths: 14 µm, 20 µm, 26 µm, and 32 µm\u003c\/li\u003e\n\u003cli\u003eCentral 25 µm pinhole for alignment\u003c\/li\u003e\n\u003cli\u003e4mm slit length for extended objects\u003c\/li\u003e\n\u003cli\u003e16mm x 16mm fused silica substrate\u003c\/li\u003e\n\u003cli\u003e2mm substrate thickness for durability\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\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\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\u003eStar’Ex 14-20-26-32 µm slit + 25 µm hole (GEN2)\u003c\/h2\u003e\n\u003cp\u003eThe Star’Ex GEN2 4-position reflective slit provides four distinct slit widths—14 µm, 20 µm, 26 µm, and 32 µm—engraved on a 16mm square substrate using high-precision photolithography. A central 25 µm pinhole acts as an artificial star for easy setup, and the entire 2mm thick component is made from robust fused silica for extended spectral transparency down to 375 nanometers. Each 4mm long slit is widened by a factor of 10 at its end to facilitate advanced spectrophotometric calibration.\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\u003eFour Slit Options from 14 µm to 32 µm for Versatile Spectroscopy\u003c\/h3\u003e\n\u003cp\u003eThis second-generation slit offers four distinct apertures arranged in a square, allowing you to match the spectrograph's resolution to your target and seeing conditions. The narrow 14 µm slit is ideal for achieving very high spectral resolution on bright targets with a small telescope. In contrast, the wider 32 µm slit is better suited for low-resolution work or capturing faint signal with larger instruments, such as a 300 mm telescope, where maximizing light input is critical.\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\u003e2mm Fused Silica Construction with UV Transparency\u003c\/h3\u003e\n\u003cp\u003eThe substrate is a 2mm thick, 16mm square blade of fused silica (synthetic quartz), chosen for its exceptional durability and broad spectral transmission. This material is transparent deep into the ultraviolet, offering a modest but useful gain around 375 nanometers even with the standard Star'Ex optics. The 2mm thickness makes the slit robust against mishandling and allows both sides to be cleaned easily with a dampened cotton swab.\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\u003eIntegrated 25 µm Pinhole: An Artificial Star for Easy Benchtop Setup\u003c\/h3\u003e\n\u003cp\u003eA major innovation of the GEN2 design is the central 25 µm diameter hole. This pinhole acts as a perfect artificial star, allowing you to fully align and focus your spectrograph on a workbench without needing a telescope or a clear night sky. This feature dramatically simplifies the initial setup and calibration process, ensuring your instrument is perfectly configured before you attach it to the telescope.\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\u003e4mm Length and Widened Ends for Advanced Spectrophotometry\u003c\/h3\u003e\n\u003cp\u003eEach slit is 4mm long, enabling you to capture spectra from extended objects like nebulae or comets. Furthermore, the final 0.5mm of each slit is widened by a factor of 10. This unique design provides critical data on atmospheric turbulence and instrument performance, and it is essential for acquiring the spectrophotometric data needed to calibrate your spectra in absolute flux values.\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 are the different slit widths on the Star’Ex GEN2 slit for?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe four widths allow you to optimize your spectrograph for different goals.\n\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e14 µm \u0026amp; 20 µm:\u003c\/strong\u003e Best for high-resolution spectroscopy on bright stars where fine spectral detail is the priority.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e26 µm \u0026amp; 32 µm:\u003c\/strong\u003e Ideal for lower-resolution work on fainter objects or with larger telescopes, as they allow more light to enter the spectrograph.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the purpose of the 25 µm central hole on the Star'Ex GEN2 slit?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e25 µm central hole\u003c\/strong\u003e serves as an artificial star. It allows you to perform a complete optical setup and alignment of your spectrograph on a workbench with a simple light source, without needing to attach it to a telescope. This makes initial configuration significantly easier and more precise.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow would I choose between the 14 µm and 32 µm slits for a 300 mm telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFor a 300 mm telescope, the \u003cstrong\u003e32 µm slit\u003c\/strong\u003e is generally the better choice. Its wider aperture is better matched to the typical seeing conditions and image scale of a larger instrument, allowing more light from your target to pass into the spectrograph. The 14 µm slit would be extremely difficult to use under average seeing and would discard most of the starlight.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the Star'Ex GEN2 slit made of and why does it matter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe slit is made from a \u003cstrong\u003e2mm thick plate of fused silica\u003c\/strong\u003e. This material offers two key advantages:\n\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDurability:\u003c\/strong\u003e It is mechanically robust and easy to clean without risk of damage.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUV Transparency:\u003c\/strong\u003e It transmits light well into the ultraviolet portion of the spectrum (down to ~375 nm), allowing for astrophysical studies in wavelengths that are inaccessible with standard glass.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the Star’Ex GEN2 slit come with a holder?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, the slit is delivered without its 3D-printed support. You will need to either 3D print the support part yourself using the plans provided by the manufacturer or design a custom holder for your specific instrument.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the 4mm slit length on the Star'Ex GEN2 to get a spectrum of the Orion Nebula (M42)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The long \u003cstrong\u003e4mm slit length\u003c\/strong\u003e is specifically designed for capturing spectra of objects with large angular sizes, such as the Orion Nebula (M42) or comets. This allows you to study how the spectral characteristics change across different regions of the nebula in a single exposure.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct\u003c\/td\u003e\n\u003ctd\u003e4-Position Reflective Slit (GEN2)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSlit Widths\u003c\/td\u003e\n\u003ctd\u003e14 µm, 20 µm, 26 µm, 32 µm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCentral Pinhole Diameter\u003c\/td\u003e\n\u003ctd\u003e25 µm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSlit Length\u003c\/td\u003e\n\u003ctd\u003e4 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate Material\u003c\/td\u003e\n\u003ctd\u003eFused Silica (Synthetic Quartz)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate Dimensions\u003c\/td\u003e\n\u003ctd\u003e16 mm x 16 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate Thickness\u003c\/td\u003e\n\u003ctd\u003e2 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoatings\u003c\/td\u003e\n\u003ctd\u003eAnti-reflective (one side), Opaque Chromium (slit side)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatibility\u003c\/td\u003e\n\u003ctd\u003eStar’Ex Spectrographs, custom instruments\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eStar’Ex GEN2 4-Position Slit\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\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":52943055159581,"sku":"SHK-SE0288","price":92.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Shelyak-Star-Ex-14-20-26-32-m-slit-25-m-hole-GEN2-1_4f93cd48-7203-4178-9c33-d324015bfd63.jpg?v=1789616548","url":"https:\/\/davidastro.com\/fr-us\/products\/shelyak-se0288","provider":"David Astro","version":"1.0","type":"link"}