Search Publications
Impact of Magnetic Environment on the Generation of High-Energy Neutrons at the Sun
Torsti, J.; Usoskin, I. G.; Kocharov, L. G. +3 more
This paper demonstrates the important interplanetary manifestation of strongly tilted magnetic fields at the flare site. We start with analysis of Big Bear Solar Observatory (BBSO) observations of magnetic structures at sites of two flares responsible for >100 MeV neutron events. Based on these observations, a model of neutron production is con…
The Galactic Cosmic Ray 36Cl Clock: ULYSSES HET Results
Simpson, J. A.; Du Vernois, M. A.; Connell, J.
Chemical vapor deposited silicon carbide mirrors for extreme ultraviolet applications
Saha, Timo T.; Leviton, Douglas B.; Fleetwood, Charles M. +5 more
Advances in optical coating and materials technology have made possible the development of instruments with substantially improved efficiency in the extreme ultraviolet (EUV). For example, the development of the chemical vapor deposition (CVD) SiC mirrors provides an opportunity to extend the range of normal-incidence instruments dow to 60 nm. CVD…
The Program to Link the HIPPARCOS Reference Frame to an Extragalactic Reference System Using the Fine Guidance Sensors of the Hubble Space Telescope
Benedict, G. F.; Franz, O. G.; Hemenway, P. D. +19 more
The Hipparcos Satellite Mission has produced positions, proper motions, and parallaxes of unprecedented accuracy for 118,000 stars. For the positions and proper motions to represent true directions and physical motions in space, they must refer to an accurate realization of a nonrotating (inertial) reference frame. One of the major problems confro…
The Jet Driven Motions in the Narrow Line Region of NGC 1068
Robinson, Andrew; Axon, David J.; Marconi, A. +2 more
We have obtained HST FOC f/48 long-slit spectroscopy of the central 2 arcseconds of the Narrow Line Region of NGC 1068 between 3500-5400\OA with a spectral resolution of 1.78\OA/pixel. At a spatial scale of 0″.0287 per pixel these data provide an order of magnitude improvement in resolution over previous ground based spectra and allow us to trace …
An explanation for the absence of sounder-stimulated gyroharmonic resonances in the Io plasma torus by the Ulysses relaxation sounder
Stone, R. G.; Fainberg, J.; Benson, R. F. +2 more
Plasma resonances were excited by the relaxation-sounder component of the unified radio and plasma wave instrument (URAP) during the Ulysses encounter with Jupiter's Io plasma torus. The observed resonant spectra were quite different than expected, based on earlier published observations from topside sounders in the terrestrial ionosphere and rela…
Ultraviolet interstellar linear polarization. IV. Cross-calibration between the Wisconsin ultraviolet photo-polarimeter experiment and the faint object spectrograph.
Martin, P. G.; Whittet, D. C. B.; Clayton, Geoffrey C. +6 more
The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) and the Faint Object Spectrograph (FOS) started gathering UV spectropolarimetry in 1990. Each observed a wide range of polarimetrically interesting objects before being retired. This paper examines the polarimetric calibration of each instrument and compares the absolute calibrations t…
The Ulysses north polar pass: Latitudinal gradients of anomalous cosmic ray O, N And Ne
Sanderson, T. R.; Marsden, R. G.; Trattner, K. J.
A key finding of the Ulysses mission has been the absence of large latitudinal gradients in the Anomalous Cosmic Ray (ACR) component. Studies using data from several satellites have consistently shown a small (∼ 2%/deg.) positive latitudinal gradient for anomalous O, N and Ne in the energy range 4 to 30 MeV/n, and even smaller gradients for ACR He…
A Reassessment of the IUE Emission Line Spectrum of the Planetary Nebula NGC 5189 and Its Central Star
Feibelman, W.
Archival high-and low-dispersion IUE spectra of NGC 5189 and its central star were reexamined. It was found that earlier published results misinterpreted nebular features for stellar emission lines due to incorrect coordinates and/or incorrect pointing of the spacecraft. NGC 5189 has a UV spectrum rich in emission lines of He II, C II], C III, C I…
Studies of Mira Stars and Their Small-Amplitude Relatives
Percy, John R.
Some aspects of the nature and evolution of Mira stars and their small-amplitude relatives are briefly described. As stars ascend the asymbiotic giant branch, it appears that they begin to pulsate when their effective temperature drops below 3800 K. The amplitude tends to increase with decreasing temperature. The stars show appreciable periodicity…