During the Astro-1 mission, an aluminum filter was used to block first-order light, and two white dwarfs (G191-B2B and HZ 43) were observed in second order. The flux from these second-order observations were then subtracted from the first-order spectra of these two objects. This was the only time that such second-order corrections were applied to HUT spectra, because no second-order observations were obtained during Astro-2 due to the SiC coating used on the HUT optics during that mission.

Because these spectra are in a different format compared to the rest of the HUT data products on MAST, we provide them here as a High Level Science Product. The files are simple, two-column text files, where Column 1 is the wavelength in Angstroms, and Column 2 is the flux in units of erg/cm^2/s/Angstrom. These spectra are originally described in Kruk et al. 1997, ApJ, 482, 546, Sections 2.2 and 5 (Figs. 2 and 8), respectively.

Note that the extracted spectra and quick-look plots for the second-order spectra of these two white dwarfs (Data IDs HUT109702 and HUT105203) in the HUT database are in units of counts per second, rather than the nominal erg/cm^2/s/Angstrom. Furthermore, no inverse sensitivity curve is available for these second-order spectra, and the inverse sensitivity curves in their IDF FITS headers should not be used.