AN ULTRAVIOLET SPECTRAL ATLAS OF A SUNSPOT AND AN ACTIVE REGION 1190-1730-A

An ultraviolet spectral atlas of a sunspot with high spectral and spatial resolution in the wavelength region 1190-1730 angstrom is presented. The sunspot was observed with the High Resolution Telescope and Spectrograph (HRTS) from a rocket in 1978. The spatial resolution on this flight was 2" with a time resolution from 0.2 to 20.2 s. The atlas contains spectra of three different areas in the sunspot and also of an active region and a quiet region. The selected areas are averaged over several arcsec, ranging from 3.5" in the sunspot to 18" in the quiet region (see Table 4). Brief descriptions of the data reduction and calibration procedures are given. The absolute intensities are determined with an accuracy of +/- 30% and the wavelength scale is accurate to better than 0.01 angstrom. The transition region lines show the most extreme example known of downflowing gas above a sunspot, a phenomenon which seems to be commonly connected to sunspots (e.g., Kjeldseth-Moe et al.). The atlas is available in a machine-readable form together with an IDL program to interactively measure linewidths, total intensities, and solar wavelengths.