{"product_id":"shelyak-se0151","title":"Shelyak Alpy Guiding Mirror with 50 µm Slit","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e50 µm Slit Width\u003c\/li\u003e\n\u003cli\u003eIntegrated Guiding Mirror\u003c\/li\u003e\n\u003cli\u003eCompatible with Alpy Spectrograph Systems\u003c\/li\u003e\n\u003cli\u003eOptimized for Faint Object Spectroscopy\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\u003eShelyak Alpy Guiding Mirror with 50 µm Slit\u003c\/h2\u003e\n\u003cp\u003eThe Shelyak Alpy Guiding Mirror with a 50 µm slit is a key component for the Alpy series of spectrographs, engineered to maximize light throughput from faint celestial targets. This specific slit width offers a practical balance, capturing more photons from diffuse objects like galaxies and nebulae compared to narrower slits, making it an essential choice for low-signal scientific work.\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\u003eThe Dual-Function Alpy Guiding Mirror: A 50 µm Aperture\u003c\/h3\u003e\n\u003cp\u003eThis component serves a dual purpose critical to successful spectroscopy. The precision-cut 50 µm slit allows the focused starlight to pass through to the spectrograph's grating, while the highly reflective mirrored surface surrounding the slit directs the rest of the field of view to your guiding camera. This allows for precise, long-exposure guiding directly on your target, ensuring the star remains perfectly centered on the narrow slit for the duration of the observation.\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\u003e50 µm vs. 25 µm Slit: Trading Resolution for Throughput\u003c\/h3\u003e\n\u003cp\u003eChoosing a slit size is a fundamental compromise between spectral resolution and signal-to-noise ratio. The 50 µm slit is the preferred option when the primary goal is capturing a spectrum from a faint object, where every photon counts.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e50 µm Slit (This Product):\u003c\/strong\u003e Doubles the light-gathering area compared to a 25 µm slit, significantly improving the signal on faint galaxies, nebulae, or low-magnitude stars. This comes at the cost of lower spectral resolution, where fine spectral lines may appear broader.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e25 µm Slit:\u003c\/strong\u003e Offers higher spectral resolution, allowing for the separation of closely spaced spectral lines. This is ideal for studying bright stars with complex spectra but can make it challenging to acquire a usable signal from fainter targets.\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\"\u003eWhen should I choose the 50 µm slit for my Alpy spectrograph?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYou should choose the \u003cstrong\u003e50 µm slit\u003c\/strong\u003e when your primary targets are faint, diffuse objects. This includes galaxies, planetary nebulae, and low-magnitude variable stars. The wider aperture allows more light to enter the spectrograph, improving your signal-to-noise ratio at the expense of some spectral resolution.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the Alpy 50 µm slit affect the spectrum of a faint galaxy like the Whirlpool Galaxy (M51)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFor a target like M51, the \u003cstrong\u003e50 µm slit\u003c\/strong\u003e is highly advantageous. It will allow you to capture a usable signal from the galaxy's core in a much shorter time than a narrower slit. While you will lose some resolution, you will be able to clearly identify major features like H-alpha emissions and determine the galaxy's overall redshift.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I study the emission lines of a bright Be star like Gamma Cassiopeiae with the 50 µm slit?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, you can absolutely use the \u003cstrong\u003e50 µm slit\u003c\/strong\u003e for a bright star like Gamma Cassiopeiae. You will easily capture the prominent Hydrogen-alpha emission line. However, for resolving very fine structures or subtle Doppler shifts in the line profile, a narrower slit like the 25 µm version would provide higher resolution and more detailed results.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main advantage of the Alpy 50 µm slit over a 25 µm slit?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe main advantage is \u003cstrong\u003elight throughput\u003c\/strong\u003e. The 50 µm slit has a larger open area, allowing significantly more light to pass into the spectrograph. This is critical for reducing exposure times and achieving a better signal-to-noise ratio on faint objects, which might be impossible to record with a narrower slit.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the guiding mirror on the 50 µm slit work?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe component is a mirror with a tiny, central slit. Your telescope focuses the star field onto this mirror. The light from the target star goes through the \u003cstrong\u003e50 µm slit\u003c\/strong\u003e into the spectrograph. The surrounding stars in the field of view are reflected off the mirror's surface and into a separate guiding camera, allowing you to maintain perfect tracking for long exposures.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 50 µm slit compatible with all Shelyak Alpy models?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the \u003cstrong\u003e50 µm slit\u003c\/strong\u003e is designed as a modular component for the Shelyak Alpy ecosystem. It is compatible with spectrograph models like the Alpy 600 and the Alpy 200 base module, allowing you to swap slits based on your observing goals for the night.\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\u003eSlit Width\u003c\/td\u003e\n\u003ctd\u003e50 µm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eGuiding Mirror Slit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatibility\u003c\/td\u003e\n\u003ctd\u003eShelyak Alpy Spectrographs\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\"\u003e50 µm Guiding Mirror 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\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_Alpy_Guiding_Module_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 Alpy Guiding Module 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":52943049457949,"sku":"SHK-SE0151","price":221.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Shelyak-50-m-slit-1_a440b1ee-2783-4775-bcef-a31672128820.jpg?v=1789616384","url":"https:\/\/davidastro.com\/fr-us\/products\/shelyak-se0151","provider":"David Astro","version":"1.0","type":"link"}