Astronomy and Astrophysics – Astronomy
Scientific paper
Mar 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994soph..150...19b&link_type=abstract
Solar Physics, vol. 150, no. 1-2, p. 19-47
Astronomy and Astrophysics
Astronomy
13
Brightness Temperature, Chromosphere, Emission Spectra, Excitation, Faculae, Photosphere, Solar Atmosphere, Solar Limb, Solar Temperature, Stellar Models, Ultraviolet Astronomy, Ultraviolet Spectra, Astronomical Photometry, Least Squares Method, Optical Transition, Rocket-Borne Instruments, Spaceborne Telescopes, Spacelab Payloads, Spectrograms, Spectrographs, Spectroheliographs
Scientific paper
The solar ultraviolet (UV) continuum has been derived from intensity-calibrated observations with the High-Resolution Telescope and Spectrograph -- HRTS -- on its second rocket flight in 1978. A database has been constructed using the spatially-resolved solar spectrum 1180 -- 1700 A along a slit extending from near disk center to the solar limb and crossing a sunspot and two active regions. The angular resolution is approximately 1.8 sec. The data consist of 1772 spectral scans in the full center-to-limb range, including both quiet and active solar regions. The distribution of solar UV intensities has been derived and the center-to-limb variations of the continuum intensities in the quiet Sun are studied. Both quantities show spectral variations, particularly across the Si I continuum edge at 1521 A. The spectra have been fitted to curves of constant color temperature above and below the Si I edge. The derived center-to-limb variations have been compared to the values of Samain (1979) which are frequently referred to in the literature. A relatively large discrepancy may be explained by the higher spectral and angular resolution of the HRTS as compared to the rocket instrument used by Samain. Comparisons with the VAL III model calculations by Vernazza, Avrett, and Loeser (1981) show discrepancies between the observations and the model predictions, particularly with regard to the sign and amount of the intensity change across the Si I continuum edge. It is noted that some of the results presented, i.e., absolute intensities and brightness temperatures may change, pending confirmation of the Spectral Irradiance Monitor (SUSIM) Spacelab 2 irradiance results (VanHoosier et al., 1988).
Brekke Paal
Kjeldseth-Moe Olav
No associations
LandOfFree
The solar UV continuum 1440-1680 A and its center-to-limb variation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The solar UV continuum 1440-1680 A and its center-to-limb variation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The solar UV continuum 1440-1680 A and its center-to-limb variation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1587640