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The Alpha Lyrae (Vega) Spectral Atlas

[Alpha Lyr Sample Spectrum]

The primary reference for the Copernicus Spectral Atlas of Vega is Rogerson, J. B., (1989ApJS...71.1011R). The summary information that follows is taken from that reference.

The observations used to construct this atlas were obtained during 1975 September 12-21 and 1975 September 27-October 7. Several gaps were filled in on 1976 April 20. The spectral atlas covers wavelengths from 2000 Å to 3187 Å (first order), with a spectral resolution of 0.1 Å. The scans were made in the V1 detector. A complete description of the Copernicus science instrument may be found in Rogerson et al. (1973ApJ...181L..97R).

Wavelengths were corrected for Doppler shifts due to (a) the heliocentric radial velocity of Vega, (b) the Earth's heliocentric velocity in the direction of Vega, and (c) the component of the satellite geocentric orbital velocity in the direction of Vega. The counts from the source were corrected for counts due to cosmic rays and trapped charge particles, guiding errors and scattered light within the spectrometer. No correction was made for the wavelength variations in the spectrometer sensitivity.

The atlas is a compilation of 23 separate scans of specific spectral regions. There are four files relating to these observations. The file numbers start at 2 following the original naming convention used at NSSDC. File 2 contains the air spectrum; file 3 is the normalization continuum and estimated scattered light; file 4 contains the equivalent flux values in 20 Å intervals in ergs/cm²/s/Å; and file 5 contains the table of line identifications.


alphalyr2.fts  28724    3     2000.612  3187.295   air spectrum
alphalyr3.fts    239    3     2000.0    3187.0     norm. cont. & scat.
alphalyr4.fts     61    4     2000.0    3200.0     equiv. flux 
alphalyr5.fts   2167    8     2000.8    3186.8     line id table