
We are now accepting pre-orders in 3rd batch (expected to be shipped end of this April)
-This has become a HOT Product! - Secure your pre-order today
Stay Tuned for a streaming event Saturday March 15th weather permitting!
watch the new Dylan O'Donnell video
https://www.youtube.com/watch?v=12i19HO1CIc
What is a Spectroheliograph?
The Spectroheliograph/Solar Spectograph is far from a modern invention—it’s actually one of the oldest techniques used to observe the Sun in narrow bands of light. It was first developed by George Ellery Hale and Henri-Alexandre Deslandres in the 1890s. Thanks to recent progress in software and hardware, the Spectroheliograph has transitioned into the digital age. Image capture and reconstruction are now done digitally using specialized software.
The SHG delivers super-high contrast with an ultra-narrow bandpass. While a top-notch etalon filter might hit around 0.5 Angstrom FWHM (and those crazy 0.3A ones cost a fortune), the SHG easily resolves between 0.06 and 0.1 Angstrom per pixel with very high finesse. This means insanely high contrast images without any parasitic light leaks from the photosphere, which you get with single stack etalons..
HGs don’t have the same “sweet spot” effect you get with etalon filters. The entire field of view (FOV) maintains the same contrast, detail, and sharpness with exceptional uniformity.
This makes SHGs perfect for full disk imaging, giving you a uniform, high-contrast view of the entire Sun.
Observing the Sun spectrally with an SHG provides a wealth of information. Beyond just capturing contrast and details, you also get Doppler shift data, which allows you to measure plasma speed. This means you can determine whether plasma is moving toward Earth or away, and how fast it's going—kind of like having your own cosmic speedometer. You can even pull off some clever tricks, like observing the Zeeman split in the iron absorption line to detect magnetic fields in the Sun's atmosphere. With that info, you can draw a magnetogram, giving you insight into the Sun’s magnetic activity. Or as the image above, you can plot out the Sun's rotation through Dooplergram
Here’s how it works: A slit captures a thin slice of sunlight, which passes through a lens to turn it into parallel rays. These rays hit a diffraction grating, dispersing the light into a spectrum. A lens then refocuses the spread light onto a camera sensor. By adjusting the angle of the grating, you can select which part of the spectrum is focused on the sensor, allowing for the observation of the Sun in different wavelengths (like H-alpha, Sodium D, Helium D3, or Ca K).
Details and contrast of the Sun are captured in slices, recorded as a video while the mount slowly moves, causing the Sun’s image to "scan" across the slit. Specialized software then reconstructs the complete image of the Sun from this video data.
Here is a video from the Manufacturer walking through the set up of this product:
https://www.youtube.com/watch?v=7ulsH6fF1EM&embeds_referring_euri=https%3A%2F%2Fmlastro.com%2F
Additional pieces you will need:
A T2 (M42) to 1.25" female adapter for connecting the camera to the SHG.
A 1.25" to M42 nosepiece for attaching the SHG to your telescope.
A monochrome digital camera.
A telescope under 700mm Focal Length and under 102mm Aperture
An Equatorial computerized mount