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.

Price - £2820.00 + £10.00 shipping & insurance.

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

Price - £3635.00 + £10.00 shipping & insurance.

The Astronomy Shop

1 Tone Hill. Wellington

Somerset TA21 0AU

United Kingdom

Telephone: +44 (0)1823 665510