866 research outputs found
Final S020 Skylab experiment report
After the loss of the meteroid shield required using the solar scientific airlock to erect the sun shade, methods were improvised to operate the S020 experiment on EVA's. Almost no data was obtained in the wavelength range 10 to 110 A. From 110 to 280 A the spectra were 10 to 100 time less intense than expected. A probable cause in loss of instrument sensitivity is the contamination of the filters by the spacecraft coolant. A list of observed lines in presented. Although less data was obtained than expected, several lines not previously observed were recorded; and the spectra serve to confirm many very faintly observed weak lines recorded from sounding rockets by other experiments
On the Size of Structures in the Solar Corona
Fine-scale structure in the corona appears not to be well resolved by current
imaging instruments. Assuming this to be true offers a simple geometric
explanation for several current puzzles in coronal physics, including: the
apparent uniform cross-section of bright threadlike structures in the corona;
the low EUV contrast (long apparent scale height) between the top and bottom of
active region loops; and the inconsistency between loop densities derived by
spectral and photometric means. Treating coronal loops as a mixture of diffuse
background and very dense, unresolved filamentary structures address these
problems with a combination of high plasma density within the structures, which
greatly increases the emissivity of the structures, and geometric effects that
attenuate the apparent brightness of the feature at low altitudes. It also
suggests a possible explanation for both the surprisingly high contrast of EUV
coronal loops against the coronal background, and the uniform ``typical''
height of the bright portion of the corona (about 0.3 solar radii) in full-disk
EUV images. Some ramifications of this picture are discussed, including an
estimate (10-100 km) of the fundamental scale of strong heating events in the
corona.Comment: To appear in APJ, June 2007; as accepted Feb 200
The Inversion of the Real Kinematic Properties of Coronal Mass Ejections by Forward Modeling
The kinematic properties of coronal mass ejections (CMEs) suffer from the
projection effects, and it is expected that the real velocity should be larger
and the real angular width should be smaller than the apparent values. Several
attempts have been tried to correct the projection effects, which however led
to a too large average velocity probably due to the biased choice of the CME
events. In order to estimate the overall influence of the projection effects on
the kinematic properties of the CMEs, we perform a forward modeling of the real
distributions of the CME properties, such as the velocity, the angular width,
and the latitude, by requiring their projected distributions to best match the
observations. Such a matching is conducted by Monte Carlo simulations.
According to the derived real distributions, it is found that (1) the average
real velocity of all non-full-halo CMEs is about 514 km s, and the
average real angular width is about 33, in contrast to the
corresponding apparent values of 418 km s and 42.7 in
observations; (2) For the CMEs with the angular width in the range of
, the average real velocity is 510 km s and the
average real angular width is 43.4, in contrast to the corresponding
apparent values of 392 km s and 52 in observations.Comment: 8 pages, 4 figures, to be published in Res. Astron. Astrophys. (RAA
Photographs of coronal streamers from a rocket on 9 May 1967
Analysis of coronal streamers photographed by white light coronagraphs flown on Aerobee 150 vehicl
Exceptional Circumstances: The Material Benefit Rule in Practice and Theory
The collapse of Starr\u27s seemingly meritorious claim and the court\u27s interestingly inconsequential mention of Section 86 raise the motivating questions of this article. First, is Section 86 and the material benefit rule it embodies ever applied in court, and, if so, can a unifying theme be found between those cases in which courts choose to enforce the post-benefit promise and those in which they do not
Beyond Google Docs: Using Free, Web-Based Tools for Management and Collaboration in your Library
Spotlight session at the annual meeting of the Academic Library Association of Ohio, Toledo, OH, November 2011
Use of the Moon to Distinguish the F from the K Corona Using a Rocket Coronagraph During an Eclipse
F and K corona observations by rocket coronagraph during solar eclips
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