Search Publications
Corotating interaction regions
Heber, B.; Zhang, M.; Sanderson, T. R.
Corotating Interaction Regions are long lasting large-scale plasma structures generated in low and middle latitude regions of the heliosphere by the interaction of a stable fast solar wind stream with the surrounding slow solar wind. Associated with these plasma structures are recurrent MeV-ion events and recurrent decreases of the galactic and an…
Transient supersoft X-ray emission from V 751 Cygni during the optical low-state
Greiner, J.; González-Riestra, R.; Di Stefano, R. +4 more
We have observed V 751 Cyg with the ROSAT HRI in a target-of-opportunity mode during its recent optical low state and clearly detect it at a count rate of 0.015 cts s(-1) . The X-ray intensity is a factor of 7-19 (depending on the exact X-ray spectral shape) higher than the upper limit obtained with the ROSAT PSPC during the optical high state, th…
Astrometry with Hubble Space Telescope Fine Guidance Sensor 3: The Parallax of the Cataclysmic Variable RW Triangulum
McArthur, B. E.; Benedict, G. F.; Girard, T. +12 more
RW Triangulum (RW Tri) is a 13th magnitude nova-like cataclysmic variable star with an orbital period of 0.2319 days (5.56 hr). Infrared observations of RW Tri indicate that its secondary is most likely a late-K dwarf (Dhillon). Past analyses predicted a distance of 270 pc, derived from a blackbody fit to the spectrum of the central part of the di…
Hubble Space Telescope Images of Magellanic Cloud Planetary Nebulae: Data and Correlations across Morphological Classes
Barlow, M. J.; Blades, J. C.; Liu, X. -W. +2 more
The morphology of planetary nebulae (PNs) provides an essential tool for understanding their origin and evolution, since it reflects both the dynamics of the gas ejected at the tip of the asymptotic giant branch phase and the central-star energetics. Here we study the morphology of 27 Magellanic Cloud planetary nebulae (MCPNs) and present an analy…
Nearby Hipparcos Eclipsing Binaries for Color-Surface Brightness Calibration
Kruszewski, A.; Semeniuk, I.
This paper contains the list of Hipparcos eclipsing binaries that fulfill the following conditions: the star is classified in the Hipparcos Catalogue as EA-type eclipsing binary and its parallax is either larger than 5 mas or it is five times larger than its mean error. An eclipsing binary with known distance and with photometric and double-line s…
Late-type giants with infrared excess. I. Lithium abundances
de Laverny, P.; Thévenin, F.; Jasniewicz, G. +1 more
de la Reza et al. (1997) suggested that all K giants become Li-rich for a short time. During this period the giants are associated with an expanding thin circumstellar shell supposedly triggered by an abrupt internal mixing mechanism resulting in the surface Li enrichment. In order to test this hypothesis twenty nine late-type giants with far-infr…
The Discovery of Two New Bipolar Proto-Planetary Nebulae: IRAS 16594-4656 and IRAS 17245-3951
Kwok, Sun; Hrivnak, Bruce J.; Su, Kate Y. L.
We report the discovery of two new, bipolar proto-planetary nebulae (PPNs). Both are cool IRAS sources for which we have confirmed optical counterparts by our 10 µm observations. Ground-based visible and infrared photometry was combined with the IRAS photometry and spectroscopy to produce their spectral energy distributions (SEDs). These SED…
The Luminosity Function of M3
Carretta, E.; Buonanno, R.; Ferraro, F. R. +6 more
We present a high-precision, large-sample luminosity function (LF) for the Galactic globular cluster M3. With a combination of ground-based and Hubble Space Telescope data we cover the entire radial extent of the cluster. The observed LF is well fitted by canonical standard stellar models from the red giant branch (RGB) tip to below the main-seque…
A new set of HST boron observations. I. Testing light elements stellar depletion
Primas, F.; Duncan, D. K.; Peterson, R. C. +1 more
A sample of 7 new stars ranging in metallicity from [Fe/H]=-2.0 to [Fe/H]=-0.75 has been analyzed in the boron spectral region. The spectra were observed with the Goddard High Resolution Spectrograph (GHRS) of the Hubble Space Telescope (HST). The targets were selected on the basis of their lithium and beryllium abundances in order to investigate …
Measuring the Physical Properties of the Solar Corona: Results from SUMER/SOHO and TRACE
Warren, H. P.
Using SUMER observations taken above the limb of a quiet region we derive electron temperatures, emission measures, and absolute elemental abundances. This analysis, which uses recently published ionization balance calculations and the latest solar photospheric abundances, indicates that the low-FIP elements are enriched by a factor of 2.3±0.7 in …