65 research outputs found
The CALSPEC Stars P177D and P330E
Multicolor photometric data are presented for the CALSPEC stars P177D and
P330E. Together with previously published photometry for nine other CALSPEC
standards, the photometric observations and synthetic photometry from HST/STIS
spectrophotometry agree in the B, V, R, and I bands to better than 1\%
(10 mmag).Comment: 15 pages, 6 figure
IUE archived spectra
The International Ultraviolet Explorer (IUE) Satellite has been in continuous operation since January 26, 1978. To date, approximately 65,000 spectra have been stored in an archive at Goddard Space Flight Center in Greenbelt, MD. A number of procedures have been generated to facilitate access to the data in the IUE spectral archive. This document describes the procedures which include on-line quick look of the displays, search of an observation data base for selected observations, and several methods for ordering data from the archive
A New Stellar Atmosphere Grid and Comparisons with HST/STIS Calspec Flux Distributions
The Space Telescope Imaging Spectrograph (STIS) has measured the spectral
energy distributions (SEDs) for several stars of types O, B, A, F, and G. These
absolute fluxes from the CALSPEC database are fit with a new spectral grid
computed from the ATLAS-APOGEE ATLAS9 model atmosphere database using a
chi-square minimization technique in four parameters. The quality of the fits
are compared for complete LTE grids by Castelli & Kurucz (CK04) and our new
comprehensive LTE grid (BOSZ). For the cooler stars, the fits with the MARCS
LTE grid are also evaluated, while the hottest stars are also fit with the NLTE
Lanz & Hubeny OB star grids. Unfortunately, these NLTE models do not transition
smoothly in the infrared to agree with our new BOSZ LTE grid at the NLTE lower
limit of Teff =15,000K.
The new BOSZ grid is available via the Space Telescope Institute MAST archive
and has a much finer sampled IR wavelength scale than CK04, which will
facilitate the modeling of stars observed by the James Webb Space Telescope
(JWST). Our result for the angular diameter of Sirius agrees with the ground-
based interferometric value.Comment: 11 figure
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