HAO Research Highlights

Polar maps of differential TEC
August 4, 2018

It has long been recognized that during solar eclipses, the ionosphere-thermosphere system changes greatly within the eclipse shadow, due to the rapid reduction of solar irradiation.

Measured vector efficiency of an echelle grating
August 1, 2018

Roberto Casini et al report on the measurements of the vector efficiency of a reflective blazed diffraction grating, which was specially coated in order to reduce the level of polarization in the diffracted light.

Broadband fractional polarization Q/I, U/I, and V/I
August 1, 2018

We realized a laboratory experiment to study the polarization of the Na I doublet at 589:3 nm, in the presence of a magnetic eld. The purpose of the experiment is to test the theory of scattering polarization for illumination conditions typical of astrophysical plasmas.

Global maps
August 1, 2018

It is commonly believed that solar eclipses have a great impact on the ionosphere-thermosphere (I-T) system within the eclipse shadow, but little attention has been paid to the global responses to them.

Butterfly-type plots of all of the McA data
July 26, 2018

The McIntosh Archive consists of a set of hand-drawn solar Carrington maps created by Patrick McIntosh from 1964 to 2009. McIntosh used mainly H, He-I 10830Å and photospheric magnetic measurements from both ground-based and NASA satellite observations.