NASA Scientific and Technical Aerospace Reports

20040073754 Air Force Research Lab., Hanscom AFB, MA
Narrow Coronal Holes in Yohkoh Soft X-Ray Images and the Slow Solar Wind
Arge, C. N.; Harvey, K. L.; Hudson, H. S.; Kahler, S. W.; Jan. 2004; 5 pp.; In English
Contract(s)/Grant(s): Proj-2311
Report No.(s): AD-A422678; AFRL-VS-HA-TR-2004-1064; No Copyright; Avail: CASI; A01, Hardcopy
Soft X-ray images of the solar corona sometimes show narrow dark features not obviously present in HE I 10830A
images. We term these "narrow coronal holes" (NCHs). A prototype for this type of structure crossed solar central
meridian on October 29, 2001. Standard source-surface models showed open magnetic field lines in this feature, tending to
confirm its identification as a coronal hole. The magnetic field in this example is relatively strong (above 100 G in the
low-resolution Kin Peak magnetograms), and the boundaries of the open-field domain fall within the unipolar area as expected.
We have surveyed the Yohkoh SXT data for other examples of this phenomenon, and have found several candidates. From
observations of the associated solar wind, and from modeling, we find these regions to be sources of slow solar wind.
DTIC
Coronal Holes; Solar Corona; Solar Wind; X Rays
20040073758 Air Force Research Lab., Hanscom AFB, MA
Parameterizing the Wind 3DP Heat Flux Electron Data
Kahler, S. W.; Crooker, N. U.; Larson, D. E.; Jan. 2004; 5 pp.; In English
Contract(s)/Grant(s): Proj-2311
Report No.(s): AD-A422682; AFRL-VS-HA-TR-2004-1063; No Copyright; Avail: CASI; A01, Hardcopy
Solar wind heat flux (HF) electrons are valuable as tracers of the interplanetary magnetic field (IMF) topology,
distinguishing positive from negative solar polarities and indicating the presence of magnetically closed CMEs when the flows
are counterstreaming. All past applications of heat fluxes to determine field topologies have been based on visual inspection
of color spectrograms of electron pitch angle distributions (PADs). However, HF PADs can take a range of shapes and
amplitudes, which challenges the visual analysis. We now take a quantitative approach to HF analysis by parameterizing the
HF PADs of the UC Berkeley 3DP data with a Fourier harmonic analysis. We have calculated the harmonic cosine coefficients
Ao through A4 for a five-year period of the Wind 3DP data set with a lO-min time resolution. With these data we intend to
derive quantitative criteria for unidirectional and bi-directional flows and other possible diagnostics of interplanetary field
dynamics or configurations. Some initial considerations and results of the 3DP parameterization are presented.
DTIC
Heat Flux; Solar Wind
20040073765 Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA
Structure in the Dusty Debris around Vega
Wilner, D. J.; Holman, M.; Kuchner, M. J.; Ho, P. T. P.; The Astrophysical Journal; [2002]; Volume 569, pp. L115-L119; In
English
Contract(s)/Grant(s): NAG5-10365; Copyright; Avail: Other Sources; Abstract Only
We present images of the Vega system obtained with the IRAM Plateau de Bure interferometer at a 1.3 millimeter
wavelength with submillijansky sensitivity and approximately 2.5 inches resolution (about 20 AU). These observations clearly
detect the stellar photosphere and two dust emission peaks offset from the star by 9.5 inches and 8.0 inches to the northeast
and southwest, respectively. These offset emission peaks are consistent with the barely resolved structure visible in previous
submillimeter images, and they account for a large fraction of the dust emission. The presence of two dust concentrations at
the observed locations is plausible explained by the dynamical influence of an unseen planet of a few Jupiter masses in a highly
eccentric orbit that traps dust in Principal mean motion resonances. Based on observations carried out with the IRAM Plateau
de Bure Interferometer.
Author
Dust; Astrophysics; Terrestrial Planets; Solar System; Planetary Structure
20040074130 Naval Observatory, Washington, DC, USA
Gauge Freedom in the N-body Problem of Celestial Mechanics
Efroimsky, M.; Goidreich, P.; Oct. 22, 2003; 14 pp.; In English
Report No.(s): AD-A422861; No Copyright; Avail: CASI; A03, Hardcopy
The goal of this paper is to demonstrate how the internal symmetry of the N-body celestial-mechanics problem can be
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