Absolute Flux Calibrations of Stars

摘要

Absolute stellar photometry is based on 1970s terrestrial measurements of the star Vega calibrated by using the Planck radiance from a Cu fixed-point blackbody. Significant advances in absolute radiometry have been made in the last 30 years that offer the potential to improve both terrestrial and space-based absolute stellar photometry. These advances include new high-temperature blackbody standards, absolute cryogenic radiometry, solid-state optical radiation sources, improved atmospheric transmittance modeling, and laser-based radiometric calibration. We describe the possible use of these new technologies for ground-based calibration of standard stars and their impact on stellar photometry, including present efforts to achieve highly accurate measurements from the ultraviolet to the near infrared for cosmological applications.