Abstract

The Aerospace program to observe bright infrared (IR) stars, including variables, and make them into temporary standard candles to calibrate space-based sensors has been in its operational phase for several years. The observations-based program and the instruments that are being used to obtain the observations will be described. At the present time, four instruments on three telescopes have been used in the production of these high quality spectral energy distributions (SED). The results of the observations with two of these instruments will be compared and shown to meet the 8% absolute radiometric requirement for the catalog. This paper will show comparisons of spectrophotometry with stellar models normalized to COBE photometry for spectral types that are not expected to vary. Examples of some variable star spectra at multiple epochs will be shown. These SEDs have been used to calibrate multiple on-orbit sensors in a number of programs, and where one can readily compare the ground-based thermal vacuum chamber calibration with the SED as provided by The Aerospace Corporation, the agreement has been 5% or better. For spectral types that are not expected to vary, the COBE photometry and that of the SED catalog have shown consistent agreement to 0-4%. The uniformity and reliability of the SED catalog have enabled the comparison of a number of scientific objects over many epochs with confidence at the 5% level, enabling tight constraints to be put on models for stars with dusty disks and to delineate the giant planet climactic behavior with time. This work is supported at The Aerospace Corporation by the Independent Research and Development Program. 1 Visiting Astronomer at the Infrared Telescope Facility, which is operated by the University of Hawaii under Cooperative Agreement no. NNX-08AE38A with the National Aeronautics and Space Administration, Science Mission Directorate, Planetary Astronomy Program.

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Aug 29th, 8:10 AM

Update and Status of the Aerospace Stellar Spectral Energy Distribution Catalog

The Aerospace program to observe bright infrared (IR) stars, including variables, and make them into temporary standard candles to calibrate space-based sensors has been in its operational phase for several years. The observations-based program and the instruments that are being used to obtain the observations will be described. At the present time, four instruments on three telescopes have been used in the production of these high quality spectral energy distributions (SED). The results of the observations with two of these instruments will be compared and shown to meet the 8% absolute radiometric requirement for the catalog. This paper will show comparisons of spectrophotometry with stellar models normalized to COBE photometry for spectral types that are not expected to vary. Examples of some variable star spectra at multiple epochs will be shown. These SEDs have been used to calibrate multiple on-orbit sensors in a number of programs, and where one can readily compare the ground-based thermal vacuum chamber calibration with the SED as provided by The Aerospace Corporation, the agreement has been 5% or better. For spectral types that are not expected to vary, the COBE photometry and that of the SED catalog have shown consistent agreement to 0-4%. The uniformity and reliability of the SED catalog have enabled the comparison of a number of scientific objects over many epochs with confidence at the 5% level, enabling tight constraints to be put on models for stars with dusty disks and to delineate the giant planet climactic behavior with time. This work is supported at The Aerospace Corporation by the Independent Research and Development Program. 1 Visiting Astronomer at the Infrared Telescope Facility, which is operated by the University of Hawaii under Cooperative Agreement no. NNX-08AE38A with the National Aeronautics and Space Administration, Science Mission Directorate, Planetary Astronomy Program.