Airylab has taken Celestron's excellent value EdgeHD reflector and modified it for high resolution observation and imaging of the Sun’s chromosphere in the Hα band. Based upon Celestron’s proven EdgeHD 800, a specific dieletric coating is applied to the corrector plate so it becomes an Energy Rejection Filter (ERF). A specifically designed telecentric 2.7x amplifier is then added to the telescope to provide Fabry Perrot Hα etalons up to a 44mm in diameter (not included) with an ideal beam of parallel light. No other optical system is needed besides the telecentric amplifier. An optional addition to the supplied telecentric, increasing the amplification to 3.5x is available. This will provide a slighter narrower bandpass for even more contrast. Please contact us for details about this addition.
Airylab’s HαT brings high resolution views to the Sun’s difficult to capture features such as spicules or details in prominences and inside the surface’s spots. A huge back focus range is possible from 100 to 250mm without impact on the optical performance. Thanks to the generous back focus, the HaT can be used with stacked etalons and also binoviewers without glass path correctors.
For H-Alpha use we recommend use with a Solar Spectrum Rear Mounted Etalon. These are available is a wide range of bandpass and also size. For Imaging we recommend the Solar Observer Models which are very uniform and available in a bandpass as low os 0.3A!
The HaT can also be used for imaging in the continuum band. This requires use of either a White Light Solar Filter such as the EMC or a Herschel Wedge such as our Baader or APM 1.25" or 2" models. The HaT can also be used for conventional imaging but only Bi-Colour (Red / Green) as the Blue part of the spectrum is blocked. The only area not open to the HaT is solar observing or imaging in the calcium bands and also planetary imaging in the UV band. This is because the specially coated corrector plate blocks all harmful UV wavelength and thus prevents use in sub 400nm wavelengths.
HaT Quality
The Celestron telescopes used to build the HαT are measured at the 635nm wavelength on the professional optical testing platform of Airylab before and after the ERF coating. They are guaranteed to be better than L/4 in the red spectrum. Each telescope is delivered with a test report. The aplanetic design delivers a large corrected flat field that is very tolerant to alignment uncertainties. On the 203mm model the field is corrected for a 0.25° field radius which is Sun’s full disk size and the performance is diffraction limited over the full field of a large 32mm Solar Spectrum Advanced Observer / Research Grade etalon. Thanks to the ERF, the secondary mirror stays cool and its support is protected from the direct exposition to Sun’s light by a customized white plastic cap. The dielectric coating is hardened and can be easily cleaned the same way as for a non coated plate.
The Edge 800 is a significant step up from the standard C8 Celestron SCT in optical quality. In addition to providing a flat photographic field, its design results in much smaller spot sizes particularly at 656nm.
The Airylab HaT is the ultimate reflector based solar telescope.
Ease of Use
Unlike conventional solar refractors that get big and clumsy above 150mm, the HαT is compact. The small 203mm Edge800 based model can fit on a light Celestron VX or Skywatcher HEQ5 mount and shows very stable alignment even after an extended ride in a car. The observation position on this short OTA is comfortable even when the sun is at the zenith. The closed tube design limits the heat exchange with the outside and the subsequent internal turbulence.
Getting the best from a High Resolution Solar Telescope
A High Resolution Solar Telescope can provide outstanding images of our nearest star. However its additional aperture can highlight poor seeing. To ensure you get the most from your Triband SCT we recommend its use with the Airylab Solar Scintillation Monitor (SSM). This is a device that monitors seeing quality, and if used together with Airylabs Genika Software (supplied free with all Mono Point Grey (now FLIR) cameras), it will trigger capture of images at the optimum seeing level. This saves a lot of time and can almost gaurantee the quality of the images you will capture.
Ordering
Before placing an order for an HaT, please contact us about lead times. The coating process for the corrector plate is specialised and done in batches. This means that there may be times when the HaT is not available from stock because a batch of correctors is having coating applied. In this instance there will be a delay while this happens and new scopes are built.
Overview
• Celestron 8" EdgeHD Optical Tube Assembly
• Aluminum Optical Tube
• Celestron's premium StarBright XLT coatings
• 2032 mm focal length (f/10)
• 40 mm eyepiece included (51x)
• Visual back allows for use with 1.25" accessories
• 9x50 finderscope to help accurately find objects
• Star diagonal provides more comfortable viewing position when observing objects that are high in the sky
• Mirror Support Knobs hold the mirror in place and reduces image shift during imaging.
• Tube vents with integrated 60 micron mesh filter allowing hot air to be released from behind the primary mirror
• Fastar Compatible optical tubes are equipped with a removable secondary mirror for fast f/2 ccd imaging
Specification
OPTICAL DESIGN : Aplanatic Schmidt
APERTURE : 203.2 mm (8 in)
FOCAL LENGTH : 2032 mm (80 in)
FOCAL RATIO : 10
OPTICAL TUBE : Aluminum
OPTICAL COATINGS : StarBright XLT
SECONDARY MIRROR OBSTRUCTION : 2.7 in (68.58 mm)
SECONDARY MIRROR OBSTRUCTION BY AREA : 11.4 %
SECONDARY MIRROR OBSTRUCTION BY DIAMETER : 33.8 %
OTA Length 17 in (431.8 mm)
OTA Weight 14 lb (6.35 kg)
