Astronomy Specialist




The DayStar Instruments Magnesium Quark Eyepiece reveals a whole new area of highly magnetized high energy in the bright 5172.8Å wavelength. The eye is most sensitive at this wavelength so the image is significantly brighter than calcium. Views show both plage and dark mottling of chromospheric network. 


To prevent damage to your telescope, the Quark must be used with an appropriate energy rejection filter (sold separately). For refractors under 120mm of aperture, a screw-in UV/IR-cut filter can be used if placed in front of the telescope diagonal. Do not use a UV/IR-cut filter with oil-spaced objectives or any telescope with an integrated field flattener or Petzval lens. The UV/IR-cut filter must be the first optical element to receive concentrated light.

The Magnesium I Quark cannot be used with standard red or yellow glass energy rejection filters. Recommended for use with a UV/IR cut filter for safety. The Magnesium I Quark can NOT be used with front mount ERF.

Why Magnesium I (b2)-line?

Magnesium is a highly magnetised chemical on the sun. The temperatures for energetic activity emitting this line are calculated to be extremely high. Spectroscopically, a line "splitting" called the Zeeman effect can be observed, whereas the dark absorption "splits" and occurs slightly above and below the typical wavelength where light from non-magnetized activity is absorbed. Strong absorption can be seen spectroscopically at 5172Å.

The views in Magnesium reveal plage, large scale magnetic structure and dark absorptive mottling of the chromospheric structure. The line is brighter than Calcium, Hydrogen Alpha and even Sodium. So it's going to be very easy for observers to see and the exposures will be very short.

The MgI b2 lines are a triplet. Our target is the middle, 5172.8Å line.

Magnesium I b2 line Quarks will all be 0.4Å or narrower.


The QUARK assembly is a product of DayStar Instruments, using DayStar Filters' Fabry Perot etalon technology.


  • 1.25" or 2.0" combo eyepiece snouts with safety indent slot directly into your diagonal
  • Standard 1.25 eyepiece drawtube output with optional 2" and SCT accessories available.
  • Brass compression ring to protect eyepiece.
  • Uses USB power, 5v 1.5amp
  • Includes 90-240VAC wall adapter with international plug adapters.
  • Tuning knob allows wing shifting +/- 0.5Å with detents at every 0.1Å
  • LED indicator for power, warming, ready, fault
  • 5 year warranty
  • Integrated, fully baffled 2 element telecentric 4.2X barlow optimized for 517nm
  • Integrated 12mm blocking filter
  • 21mm clear filter aperture
  • Best performance with F/4 - F/8 refractors
  • Full disk viewing possible on refractors up to ~450mm focal length refractors
  • No aperture limitations. May be used on larger refractors for higher magnification views
  • Ships in convenient Twist-Case for safe, dust-free storage.
  • Not suited for off-axis application.



DayStar Magnesium I b2 Quark Solar Filter


DayStar Magnesium I b2 Quark Solar Filter © Gary Palmer   DayStar Magnesium I b2 Quark Solar Filter
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