{"product_id":"shelyak-se0242","title":"Shelyak Grating module for the UVEX - 150 l\/mm","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e150 lines\/mm Grating Density\u003c\/li\u003e\n\u003cli\u003eDesigned for the Shelyak UVEX Spectroscope\u003c\/li\u003e\n\u003cli\u003eOptimized for Low-Resolution, Wide-Coverage Spectroscopy\u003c\/li\u003e\n\u003cli\u003eInterchangeable Module for UVEX System\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\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\u003eGrating module for the UVEX - 150 l\/mm\u003c\/h2\u003e\n\u003cp\u003eThis optional 150 lines\/mm grating module expands the capabilities of your UVEX spectroscope, sitting at the lowest-resolution end of a lineup that includes 300, 600, 1200, and 1800 l\/mm options. By trading the high resolution of the standard 600 l\/mm grating for maximum wavelength coverage, the 150 l\/mm module is purpose-built for survey work and classifying a wide range of celestial objects in a single exposure.\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\u003e150 l\/mm Grating: Maximizing Spectral Range for Survey Work\u003c\/h3\u003e\n\u003cp\u003eThe primary role of the 150 l\/mm grating is to capture the widest possible spectral range that your camera sensor can accommodate in a single frame. This low-dispersion capability is essential for survey projects where the goal is to quickly characterize many targets, such as classifying stars, identifying supernova types, or monitoring cometary emissions.\u003c\/p\u003e\n\u003cp\u003eFor faint targets, lower dispersion concentrates the object's light over fewer pixels, increasing the signal-to-noise ratio of the continuum. This makes the 150 l\/mm grating the most efficient choice for obtaining usable spectra of faint novae, asteroids, or distant quasars where capturing the overall spectral shape is more critical than resolving fine details.\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\u003eUVEX 150 l\/mm vs. 600 l\/mm Grating: Resolution vs. Wavelength Coverage\u003c\/h3\u003e\n\u003cp\u003eChoosing between the optional 150 l\/mm grating and the standard 600 l\/mm grating is a direct trade-off between spectral detail and wavelength coverage. Your scientific objective determines which is the correct tool for the job.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eStandard 600 l\/mm Grating:\u003c\/strong\u003e This grating provides four times the resolution, making it the superior choice for resolving fine spectral features. It is ideal for measuring subtle Doppler shifts, studying complex stellar atmospheres, or separating closely spaced emission lines in planetary nebulae.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptional 150 l\/mm Grating:\u003c\/strong\u003e This grating captures a much wider band of the spectrum on the same sensor. This allows you to see the entire visible spectrum of an object at once, from the violet H-delta line to the red H-alpha line, without creating a mosaic of multiple images. This is invaluable for transient events or initial object classification.\u003c\/li\u003e\n\u003c\/ul\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\"\u003eWhy would I choose the 150 l\/mm grating for my UVEX instead of the standard 600 l\/mm?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYou should choose the \u003cstrong\u003e150 l\/mm grating\u003c\/strong\u003e when your primary goal is to capture the widest possible range of wavelengths in a single exposure. It is ideal for survey work, classifying unknown objects, or studying targets with very broad spectral features. The standard \u003cstrong\u003e600 l\/mm grating\u003c\/strong\u003e is better when you need high resolution to study fine details within a narrow spectral window.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of objects, like a Type Ia supernova or a Wolf-Rayet star, are best studied with the UVEX 150 l\/mm grating?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe UVEX 150 l\/mm grating is excellent for both. \u003cstrong\u003eType Ia supernovae\u003c\/strong\u003e are identified by a characteristic broad silicon absorption feature (Si II) at 6150Å, which is easily captured with this grating's wide coverage. \u003cstrong\u003eWolf-Rayet stars\u003c\/strong\u003e have extremely broad emission lines (sometimes hundreds of angstroms wide) from stellar winds, and the 150 l\/mm grating ensures the entire profile of these features fits within a single frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the 150 l\/mm grating affect exposure times with the UVEX?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. Because the 150 l\/mm grating disperses light less than a higher-density grating, it concentrates the starlight onto fewer pixels on your camera sensor. This results in a higher signal-to-noise ratio for the stellar continuum in a given exposure time, making it more efficient for capturing spectra of faint objects.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-Q\"\u003eCan I use the UVEX 150 l\/mm grating to measure precise radial velocities?\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this is not the right tool for that task. The low resolution of the 150 l\/mm grating is insufficient for measuring the small Doppler shifts required for precise radial velocity work. For those applications, a higher resolution grating, such as the standard 600 l\/mm or the optional 1200 l\/mm, is necessary.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIf I'm trying to classify a newly discovered comet with my UVEX, is the 150 l\/mm or the 600 l\/mm grating a better choice?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e150 l\/mm grating\u003c\/strong\u003e is the better choice for initial comet classification. Cometary spectra often show broad emission bands from molecules like C2 (the Swan bands) and CN spread across the visible spectrum. The wide coverage of the 150 l\/mm grating allows you to capture all these features simultaneously to quickly assess the comet's composition.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs it difficult to swap gratings on the Shelyak UVEX?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, the Shelyak UVEX is designed as a modular system. Swapping gratings is a straightforward process, allowing you to reconfigure the spectroscope in the field to match your observing target and scientific goals for the night. Always refer to the UVEX manual for the correct procedure.\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\u003eGrating Density\u003c\/td\u003e\n\u003ctd\u003e150 lines\/mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatibility\u003c\/td\u003e\n\u003ctd\u003eShelyak UVEX Spectroscope\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\"\u003eUVEX 150 l\/mm Grating Module\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\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_UVEX_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 UVEX 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":52943051948317,"sku":"SHK-SE0242","price":719.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Shelyak-Grating-module-for-the-UVEX-150-l-mm-1_8c7669aa-09e4-416e-a28d-be125b6cbaa3.jpg?v=1789616459","url":"https:\/\/davidastro.com\/fr-us\/products\/shelyak-se0242","provider":"David Astro","version":"1.0","type":"link"}