What is the purpose of the Shelyak FIGU F/9?
The Shelyak FIGU F/9 is a specialized adapter that mounts at your telescope's focus. Its primary job is to take the light from a star captured by your F/9 telescope and inject it precisely into the 50µm optical fiber that feeds a spectrograph like the Shelyak eShel, enabling you to perform scientific spectral analysis.
Do I need a separate guide camera for the FIGU F/9?
Yes, a guiding camera is required but not included. The FIGU F/9 has a dedicated port for a guide camera, which is essential for viewing the starfield, accurately placing your target onto the fiber's entrance, and maintaining precise tracking during an exposure.
How do I switch between my star and my calibration lamp with the FIGU F/9?
The FIGU F/9 contains a remote-controlled mirror inside the unit. This allows you to electronically switch the input source from the telescope's starlight to the light from your calibration module (fed via a 200µm fiber) without physically touching or disturbing the telescope setup, ensuring repeatable and accurate calibrations.
Why do I need the F/9 version of the FIGU instead of the F/6 version for my SCT?
Standard Schmidt-Cassegrain Telescopes (SCTs) typically operate around f/10, very close to F/9. The FIGU F/9 includes a built-in focal reducer specifically to convert this slower light cone to the optimal angle for the spectrograph's fiber. Using the F/6 version on an F/9 telescope would result in significant light loss and inefficient performance. The F/9 model is purpose-built for these systems.
What spectrographs is the FIGU F/9 – 50µm designed for?
This unit is designed as a core component for Shelyak's own spectroscopy systems. It is the standard fiber injection unit for the eShel and Whoppshel spectrographs when used with an F/9 telescope.
How does the FIGU F/9 help me get an accurate spectrum of Vega (Alpha Lyrae) with my C8 at F/9?
First, you would use the guiding port on the FIGU F/9 to view the starfield and precisely center Vega (Alpha Lyrae) on the 50µm fiber optic input. Once centered, you can begin your exposure. Before or after, you use the remote control to flip the internal mirror, allowing light from your calibration lamp to enter the spectrograph. This provides a reference spectrum, which is critical for accurately calibrating the wavelength of the data you captured from Vega.