Shelyak Alpy Spectrograph

ALPY is a new modular product line for spectroscopy.

ALPY allows progressive investment with separate spectrograph, guiding and calibration modules. It is multi-purpose (on a bench or with a telescope; slit, slitless or with an optical fiber connector; visual use, with CCD camera or digital SLR...) and very easy to use with minimum adjustements to make.

ALPY is an efficient system with, for the Alpy 600, a spectral domain from near-UV to near-IR with a resolution around 10A.

The core element of the ALPY product line is the Alpy 600 spectrograph. With a 600gr/mm grism (grating + prism), Alpy 600 offers compactness, low resolution (resolving power R~600) and a dispersion compatible with the current CCD cameras used in astronomy.

The spectrograph is F/5.

The ALPY product line has been designed around standard mechanical threads (M42x075, SM1, SM05) to facilitate integration with your existing instrumentation.

The ALPY product line also includes a separate guiding module (mirror slit 23m) and a calibration module with neon/argon and tungsten lamps. These make it a complete solution for astronomical spectroscopy, but each module is independent, making ALPY unique and revolutionary.

Progressive investment (" la carte")

You have the choice of which module to purchase based on your budget and need. You can then upgrade your equipment over time through further investment. Discover slit based spectroscopy with the Alpy 600 base module which will bring you a lot of possible observation on a workbench or at your telescope. Complete your investment with a guiding module, allowing longer exposures with your CCD camera to reach fainter targets. Then add a calibration module to get easier and more accurate wavelength calibration (neon/argon) and flats (tungsten).


Beyond the modularity between the Alpy 600 spectrograph and guiding and calibration modules, the spectrograph itself is versatile and multi-purpose.

It is able to interface with most CCD cameras with a standard M42x0.75mm thread. A C-mount adapter is available as well as a barlow lens element specially designed for Digital SLRs, extending the backfocus and enlarging the spectrum.

The removable standard slit includes multiple positions (25m hole; 25m, 50m, 100m or 300m slits; 5m tolerance) with a clear position (3mm hole) for a slitless mode.

A "fiber connector" mounting is also available so Alpy 600 is compatible with our optical fiber eShel solution.

Last but not least, Alpy 600 is also a visual spectroscope (with or without slit) with an optional widening lens element. View lamps or the solar spectrum with Alpy 600 alone, look for the spectra of stars or nebulae spectra using the Alpy 600 as an eyepiece on your telescope (diameter 31.75mm).

The ALPY product line benefits from our experience and expertise in the area of astronomical spectroscopy. For example, the Alpy 600 optics have been specially designed for this spectrograph, giving an excellent quality spectrum through all the visible domain from near-UV (Balmer serie, astonishing H&K lines) to near-IR (calcium triplet).