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Connecting the Sun and the Solar Wind: Comparison of the Latitudinal Profiles of Coronal and Ulysses Measurements of the Fast Wind
Habbal, Shadia Rifai; Woo, Richard
A quantitative comparison of the latitudinal profile of polarized brightness (pB) measurements nearest the Sun at 1.15 Rsolar by the Mauna Loa Solar Observatory K-Coronameter and Ulysses interplanetary measurements of the fast solar wind during its first south polar pass, at the declining phase of the solar cycle, is made for the first …
Hubble Space Telescope NICMOS Imaging of the Cores of M31 and M32
Rieke, Marcia J.; Corbin, Michael R.; O'Neil, Earl
We present 1.1, 1.6, and 2.2 µm images of the cores of the Local Group galaxies M31 and M32 obtained with the Near Infrared Camera and Multi-Object Spectrometer of the Hubble Space Telescope (HST). These images are also compared with optical images of the galaxies obtained with the HST Wide Field Planetary Camera 2 (WFPC2). In M31, the nucle…
Periodic signals in Ulysses' energetic particle events upstream and downstream from the Jovian bow shock
Sarris, E. T.; Anagnostopoulos, G. C.; Marhavilas, P. K.
We present results from a statistical analysis of energetic particle events, observed by the Heliosphere instrument for spectra, composition, and anisotrophy at low energies (HI-SCALE) instrument onboard Ulysses, upstream from the bow shock of Jupiter, during the inbound and outbound trajectory of the spacecraft. A harmonic analysis on the intensi…
Is SBS 0335-052 a young galaxy?
Östlin, G.; Kunth, D.
The metal-poor blue compact galaxy SBS 0335-052 has been put forward as a local primeval galaxy candidate, with a proposed age less than 108 years. If true, this would imply that galaxy formation was not confined to high red-shifts, but is still occurring in the local Universe, albeit at a slower rate. In this paper we show that some of…
An Ultraviolet Study of the Short-Period Binary OO Aquilae
Guinan, Edward F.; Hrivnak, Bruce J.; Ribas, Ignasi +1 more
OO Aql is a rare W UMa-type eclipsing binary in which the two solar-type stars may have only recently evolved into contact. The binary has an unusually high mass ratio (0.84) and a relatively long orbital period (0.506 days) for its spectral type (mid-G). Twelve ultraviolet spectra of OO Aql were obtained in 1988 with the International Ultraviolet…
Speckle observations of binary systems measured by Hipparcos
Lampens, P.; Prieur, J. -L.; Aristidi, E. +4 more
From speckle observations made with the PISCO speckle camera at the Pic du Midi Observatory, we present high angular resolution astrometric data for 43 binary stars already observed by the Hipparcos satellite. This sample consists of mainly new Hipparcos eclipsing binaries with a visual companion closer than one arcsecond, chosen with the aim to s…
Long-Slit Observations of Extended C II λ1335 Emission around V854 Centauri and RY Sagittarii
Clayton, G. C.; Ayres, T. R.
We have obtained long-slit far-ultraviolet (1150-1730 Å) spectra of the R Coronae Borealis (RCB) stars V854 Cen and RY Sgr near maximum light and pulsational phase zero with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. The far-UV spectrum of each star shows a photospheric continuum rising steeply toward longer wave…
Mesogranulation and Turbulence in Photospheric Flows
Lawrence, J. K.; Cadavid, A. C.; Ruzmaikin, A.
Below the scale of supergranules we find that cellular flows are present in the solar photosphere at two distinct size scales, approximately 2 Mm and 4 Mm, with distinct characteristic times. Simultaneously present in the flow is a non-cellular component, with turbulent scaling properties and containing 30% of the flow energy. These results are ob…
The proper motions of fundamental stars. I. 1535 stars from the Basic FK5
Gontcharov, G. A.; Andronova, A. A.; Titov, O. A. +1 more
A direct combination of the positions given in the HIPPARCOS catalogue with astrometric ground-based catalogues having epochs later than 1939 allows us to obtain new proper motions for the 1535 stars of the Basic FK5. The results are presented as the catalogue Proper Motions of Fundamental Stars (PMFS), Part I. The median precision of the proper m…
Nature of the boundary between open and closed magnetic field line regions at the Sun revealed by composition data and numerical models
Riley, Pete; Gloeckler, George; Posner, Arik +5 more
Recently, Fisk et al. [1999] have presented a theory that describes a number of features of the large-scale coronal and heliospheric magnetic field. This theory predicts large-scale transport of magnetic flux across the boundaries of the polar coronal holes, which leads to reconnection processes of open field lines with preliminary closed magnetic…