New bright optical spectrophotometric standards: A-type stars from the STIS Next Generation Spectral Library

Abstract

Exoplanets have sparked interest in extremely high signal-to-noise ratio spectroscopic observations of very bright stars, in a regime where flux calibrators, in particular DA white dwarfs, are not available. We argue that A-type stars offer a useful alternative and reliable space-based spectrophotometry is now available for a number of bright ones in the range 3<V<8 mag. By means of comparing observed spectrophotometry and model fluxes, we identify 18 new very-bright trustworthy A-type flux standards for the optical range (400-800 nm), and provide scaled model fluxes for them. Our tests suggest that the absolute fluxes for these stars in the optical are reliable to within 3%. We limit the spectral range to 400-800 nm, since our models have difficulties to reproduce the observed fluxes in the near-infrared and, especially, in the near-UV, where the discrepancies rise up to ~ 10%. Based on our model fits, we derive angular diameters with an estimated accuracy of about 1%.

source files include low-resolution model fluxes

References in corpus (10)

• New Grids of ATLAS9 Model Atmospheres
• Debris Disk Evolution Around A Stars
• The SEGUE Stellar Parameter Pipeline. III. Comparison with High-Resolution Spectroscopy of SDSS/SEGUE Field Stars
• Vega is a rapidly rotating star
• First Results from the CHARA Array VII: Long-Baseline Interferometric Measurements of Vega Consistent with a Pole-On, Rapidly Rotating Star
• Center-to-Limb Variation of Solar 3-D Hydrodynamical Simulations
• A Spitzer Study of Debris Disks In The Young Nearby Cluster NGC 2232: Icy Planets Are Common Around ~ 1.5--3 Solar-Mass Stars
• The CALSPEC Stars P177D and P330E
• NICMOS Spectrophotometry and Models for A-Stars
• The Absolute Flux Distribution of LDS749B

Cited by in corpus (6)

• A collection of model stellar spectra for spectral types B to early-M
• How stellar rotation shapes the colour magnitude diagram of the massive intermediate-age star cluster NGC 1846
• Accurate parameters for HD 209458 and its planet from HST spectrophotometry
• Testing Models of Stellar Structure and Evolution I. Comparison with Detached Eclipsing Binaries
• The sdA problem I: Physical Properties
• One of Everything: The Breakthrough Listen Exotica Catalog