• The Lhires III Spectroscope by Shelyak, designed in 2003, is a flagship product for spectroscopy in various fields.
• It is used for measuring variables stars, analyzing RR Lyrae variables, high-resolution solar spectrum observations, radial star velocity, star rotation, star binaries, and the rotation of Jupiter and Saturn.
• The spectroscope has an impressive resolution power of R=17.000, allowing for the detection of subtle variations in spectral lines, including radial Doppler effects.
• The standard grating included has 2400 lines/mm, providing full resolution, and additional gratings can be purchased for different applications.
• The spectral domain of the Lhires III is mainly centered on visible wavelengths (400nm to 750nm), with a covered portion of approximately 10nm due to its high resolution.
• It is compatible with any telescope but is particularly well-suited for SCT optical designs, which have shorter focal lengths and better resolution for spectral measurements. Precise collimation is crucial for accurate spectral analysis, and SCT designs often have more reliable collimation.
• The spectroscope comes with a standard 15-19-23-35µm slit, but other slits can be purchased separately to optimize for resolution or luminosity depending on the specific application.
• The Lhires III includes an SCT adapter and can be paired with a 2" nosepiece if needed. Various adapters are available to connect different cameras, and the guiding camera port is C-mount.

The Lhires III Spectroscope is a flagship product by Shelyak created and designed in 2003 that serves an important role for spectroscopy measuring in numerous different fields including but not limited to variable star measurements, RR Lyrae variable analysis, high resolution of the solar spectrum, radial star velocity, star rotation, star binaries, and the rotation of Jupiter and Saturn. It includes an internal argon-neon lamp for calibration and an internal tungsten for flats.

The Lhires III has an immense R=17.000 resolution power and thus is capable of detecting subtle variations along spectral lines including radial Doppler effects velocities. It comes with a standard grating of 2400 lines/mm (other gratings can be purchased separately for different applications) which results in full resolution.

The Lhires III spectral domain is almost exclusively centered on the visible wavelengths (400nm to 750nm) with a covered portion approximately 10nm due to the high resolution. However, the user can choose what central wavelength to observe at their discretion depending on the application and object being observed and studied.

The Lhires III can be used with any telescope, however it is highly suggested to be paired with an SCT optical design. The reason for this is because by nature, SCT designs have shorter focal lengths (assuming a reducer is being used) and thus results in spectral lines having better resolution for spectral measurements. A secondary benefit is the collimation is almost always precise, unlike in a Newtonian Reflectors which need collimation adjustments on a regular basis. Precise collimation is crucial for accurate spectral analysis.

By default, the Shelyak Lhires III comes with the standard 15-19-23-35µm slit, which can typically be used for many applications. However, there are many other slits available that can be purchased separately that can excel at metrics such as resolution, or if luminosity is a higher more important factor, a photometric slit may be preferred as such, optimizing the Lhires III further towards this application.

The Shelyak Lhires III comes with an SCT adapter. A 2" nosepiece can be purchased separately if needed. There are also other adapters available to connect different cameras as well. The guiding camera port is C-mount.