Properties of the N964 filter

The N964 is a narrow band filter centered at 9640 Angstroms with a width of only 95 Angstroms. It was chosen to be in a part of the spectrum where the bright OH lines originating in the earth’s upper atmosphere are lacking, so the sky is relatively dark and very deep, long exposures can be taken. The filter was made by Materion and funded by an international team with P.I JunXian Wang of the University of Science and Technology, China. It is available for use of the filter by NOAO and Chilean community scientists with prior authorization from the PI and his team. Please contact us in advance if you are interested in using this filter.

The following plot shows the transmission curves over the filter: