286 research outputs found
Proceedings of the NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications
The proceedings of the National Space Science Data Center Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications held July 23 through 25, 1991 at the NASA/Goddard Space Flight Center are presented. The program includes a keynote address, invited technical papers, and selected technical presentations to provide a broad forum for the discussion of a number of important issues in the field of mass storage systems. Topics include magnetic disk and tape technologies, optical disk and tape, software storage and file management systems, and experiences with the use of a large, distributed storage system. The technical presentations describe integrated mass storage systems that are expected to be available commercially. Also included is a series of presentations from Federal Government organizations and research institutions covering their mass storage requirements for the 1990's
NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications, volume 2
This report contains copies of nearly all of the technical papers and viewgraphs presented at the NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Application. This conference served as a broad forum for the discussion of a number of important issues in the field of mass storage systems. Topics include the following: magnetic disk and tape technologies; optical disk and tape; software storage and file management systems; and experiences with the use of a large, distributed storage system. The technical presentations describe, among other things, integrated mass storage systems that are expected to be available commercially. Also included is a series of presentations from Federal Government organizations and research institutions covering their mass storage requirements for the 1990's
Polarization measurements of the polluted white dwarf G29-38
We have made high precision polarimetric observations of the polluted white
dwarf G29-38 with the HIgh Precision Polarimetric Instrument 2. The
observations were made at two different observatories -- using the 8.1-m Gemini
North Telescope and the 3.9-m Anglo AustralianTelescope -- and are consistent
with each other. After allowing for a small amount of interstellar
polarization, the intrinsic linear polarization of the system is found to be
275.3 +/- 31.9 parts-per-million at a position angle of 90.8 +/- 3.8 degrees in
the SDSS g' band. We compare the observed polarization with the predictions of
circumstellar disc models. The measured polarization is small in the context of
the models we develop which only allows us to place limits on disc inclination
and Bond albedo for optically thin disc geometries. In this case either the
inclination is near face-on or the albedo is small -- likely in the range 0.05
to 0.15 -- which is in line with other debris disc measurements. A preliminary
search for the effects of G29-38's pulsations in the polarization signal
produced inconsistent results. This may be caused by beating effects, indicate
a clumpy dust distribution, or be a consequence of measurement systematics.Comment: 15 pages, 6 figures, 4 tables. Accepted to MNRA
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