DayStar Sodium Solar Filters.

DayStar Sodium Solar Filters.

DayStar is proud to offer Sodium Na- D line (5895.9Å ) filtering systems. For visual and photographic studies. Sodium filter assemblies are designed for sub-angstrom observations with single-cavity design. Sodium lines are very narrow, but very bright. A very narrow filter of
< 0.5Å is necessary to properly isolate the line from the continuum. The resulting image depicts high detail in granulation, supergranulation and P-modes. Sodium also shows impulsive-phase flare eruption kernels. Na D is a low excitation line emitted when the low chromosphere is heated, usually at footpoints of flux loops passing through a flare, as sodium D line reflects the lower chromosphere.

Visual and photographic images reveal type image as Calcium, revealing granulation, but are much brighter and more easily visible.University series filters are designed to operate unheated on the lower of the two Na D emission lines; and can be heated to accomplish transmission on the higher of the two Na D lines, making doppler studies possible by photographing in each line and derriving difference images after subtracting an average solar velocity image. This process is referred to as a dopplergram velocity image, reveals the surface motions associated with supergranulation.

These filters have until now been primarily used for research purposes only, performing
doppler and supergranulation studies. Narrow bandpass Na D line filters have also been used
in deep-sky observations of IO, but with significantly larger apertures.Note. These systems require an energy rejection pre-filter and F/30 focal ratio for onband operation. Standard yellow glass DayStar Energy rejection filters provide sufficient off-band energy rejection, as do dielectric 'hot mirror' coated pre-filters.0.4Å Single cavity Amateur T-Scanner filter system - suitable for visual or photographic observing.

0.4Å Single cavity University series filter system - suitable for photographic and visual
observing.