What is the Star'Ex HR Optical Kit used for?
This kit provides all the necessary optical components to build a Star'Ex High Resolution (HR) spectrograph. This instrument is used to analyze the light from celestial objects like stars and nebulae, splitting it into a spectrum to study their chemical composition, temperature, and motion.
What else do I need to build the complete Star'Ex HR spectrograph?
This is an opticals-only kit. To complete the project, you will need to source or fabricate the following items separately:
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3D-Printed Body: Files are available from Christian Buil's website.
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Mechanical Parts: Screws and other hardware, potentially available in kits from vendors like Azur3dPrint.
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Adapters: To connect the spectrograph to your specific telescope and camera.
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Imaging and Guiding Cameras: A main camera for capturing the spectrum and potentially a second for guiding.
How does the Star'Ex HR achieve a resolution up to R=30,000?
The spectral resolution (R) is directly dependent on the width of the entrance slit. The Star'Ex HR design allows you to use different slits. A very narrow slit is used to achieve the highest resolution of R=30,000, which allows for extremely fine detail in the spectrum, though it requires a brighter target and good seeing.
What details can I see in the spectrum of a star like Vega (Alpha Lyrae) with the Star'Ex HR?
With the Star'Ex HR at high resolution, you can easily resolve the deep, broad absorption lines of the Balmer series (Hydrogen-alpha, beta, gamma) in Vega's spectrum. At the highest resolutions, you may also be able to detect much finer metallic lines and study the precise profile of the hydrogen lines to understand the star's atmospheric properties.
Will the Star'Ex HR kit work with my 8" f/10 Schmidt-Cassegrain telescope?
Yes, the Star'Ex HR is well-suited for common telescopes like an 8" f/10 SCT. The spectrograph's internal 125:80 reduction ratio helps to optimize the focal ratio for the camera sensor, which is beneficial when starting with a longer f-ratio telescope. You will need to ensure you have the correct adapters to physically connect the spectrograph to your telescope's visual back.
What does the 400 nm to 700 nm wavelength range of the Star'Ex HR cover?
This range covers the entire visible light spectrum that the human eye can see. It allows you to study many of the most important spectral features, including:
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Hydrogen-alpha (656 nm) and Hydrogen-beta (486 nm) lines in nebulae and stars.
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Sodium D lines (589 nm), which are prominent in stars like our Sun.
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Calcium H & K lines (~393-397 nm) at the very edge of the violet range.