NEAR-INFRARED EMISSION-LINE AND CONTINUUM OBSERVATIONS FROM THE 1991 ECLIPSE

We report observations made during the 1991 July 11 total solar eclips e from the University of Hawaii 61 cm south telescope on the summit of Mauna Kea, Hawaii, The eclipse observations entail CCD imaging of a c oronal region on the southeast limb of the Sun using four wavelength c hannels isolated with narrowband interference filters. We obtain two l ong exposure images in each channel including the continuum (lambda = 10690 Angstrom), the two near-infrared [Fe XIII] emission lines (lambd a = 10747, 10798 Angstrom), and the He I line (lambda = 10830 Angstrom ). We calibrate the images to the center-of-disk solar intensity. The [Fe XIII] images are the first coronal images published from these emi ssion lines. We find significant structural differences between the li ne and continuum images implying large temperature gradients in our sm all field of view. We compute the line ratio of the two [Fe XIII] emis sion lines (R) and find that the ratio is within the limits 1.2 greate r than or equal to R greater than or equal to 15.0. We examine the mot ion seen in the prominence structure and find transverse velocities of up to about 30 km s(-1). Finally we see no cold coronal emission to a limit of 2 x 10(-7) B..