Lunt Solar Systems Ca-K module with 2", 6mm blocking filter in extension tube for 2" focuser (15917)

Calcium K (Ca-K) Telescopes and Filters are designed for observing the Sun at a wavelength of 393.4 nm. This specific emission line, produced by calcium, is found just at the edge of the visible spectrum in a solar layer that is slightly lower and cooler than the one observed in hydrogen-alpha light. Observing the Ca-K line reveals super granulation cells, which appear brightest and strongest in regions with high magnetic fields, such as sunspots and active solar regions. By studying both the Calcium K and Hydrogen-alpha lines, astronomers gain valuable insights into the structure, intensity, and depth of these dynamic solar features.

The Ca-K line is centered at 393.4 nm, a wavelength that is slightly outside the visible spectrum on the ultraviolet side. While some people can see the violet hue of this wavelength, many cannot distinguish its contrast due to natural yellowing of the cornea. Individuals who have undergone cataract surgery often experience improved visibility of these details. Because of these visual limitations, the Ca-K line is most commonly studied using cameras, which can capture remarkable solar details.

These filters use internal narrowband technology to achieve a bandpass of less than 2.4 Angstroms. The system is primarily intended for imaging, as visual observation can be challenging for many users.

Specifications

Capacity:

Connection (to the telescope):
2-inch

Connector (at camera end):
T2

Connection (to eyepiece):
1.25-inch

Half-value width:
2.4

Frame:
2-inch

Free transmission:
6 mm

Appropriate for telescopes:
Less than 100/540 (Refractor)

General:
Type: Solar filter
Type of build: Line filter