Search Publications
HUBBLE SPACE TELESCOPE Photometry of the Globular Cluster M4
Bond, Howard E.; Ibata, Rodrigo A.; Stetson, Peter B. +5 more
This paper presents a detailed description of the acquisition and processing of a large body of imaging data for three fields in the globular cluster M4 taken with the Wide Field and Planetary Camera 2 aboard the Hubble Space Telescope. Analysis with the ALLFRAME package yielded the deepest photometry yet obtained for this cluster. The resulting d…
The Nearby Low-Mass Visual Binary Wolf 424
Torres, Guillermo; Henry, Todd J.; Wasserman, Lawrence H. +1 more
We present new measurements of the relative positions of the components of the low-mass visual binary Wolf 424 (M5.5 Ve) made with the Fine Guidance Sensors on the Hubble Space Telescope. Previous analyses of the astrometric orbit of this system indicated that the components have substellar masses (Heintz; Schultz et al.), raising considerable int…
Far-Ultraviolet Space Telescope Imaging Spectrograph Spectra of the White Dwarf REJ 1032+532. II. Stellar Spectrum
Green, E. M.; Barstow, M. A.; Bruhweiler, F. C. +2 more
We discuss the Hubble Space Telescope Space Telescope Imaging Spectrograph UV echelle spectrum of the hot DA white dwarf REJ 1032+532. The interstellar data from this spectrum are presented by Holberg and coworkers. In this paper we discuss a number of strong photospheric features due to C, N, and Si that are present in the REJ 1032+532 spectrum. …
Full disk helioseismology: repetitive music and the question of gap filling
Hoeksema, J. T.; Grec, G.; Cacciani, A. +8 more
Helioseismology requires continuous measurements of very long duration, months to years. This paper addresses the specific and limited case of full disk measurements of p-mode oscillations, although it can be generalized, to some extent, to the case of imaged helioseismology. First, a method of mode by mode (or rather pair of modes by pair of mode…
Three-dimensional reconstruction of UV emissivities in the solar corona using Ultraviolet Coronagraph Spectrometer data from the Whole Sun Month
Panasyuk, Alexander V.
UV coronal intensity data collected by the Ultraviolet Coronagraph Spectrometer on SOHO in a daily synoptic program during the Whole Sun Month are used to reconstruct the three-dimensional distribution of emissivities in the solar corona for H I Ly α and the O VI doublet at 1032 and 1037 Å. We discuss the specifics that complicate a tomographic re…
I- and JHK-band photometry of classical Cepheids in the HIPPARCOS catalog
Groenewegen, M. A. T.
By correlating the \cite[Fernie et al. (1995)]{F95} electronic database on Cepheids with the ``resolved variable catalog'' of the hipparcos mission and the simbad catalog one finds that there are 280 Cepheids in the hipparcos catalog. By removing W Vir stars (Type ii Cepheids), double-mode Cepheids, Cepheids with an unreliable solution in the hipp…
Probable Detection of a Bright Infrared Coronal Emission Line of Si IX near 3.93 Microns
Lin, H.; Mann, I.; Kuhn, J. R. +7 more
We report here the probable detection of an emission line of Si IX that was observed from an open C130 aircraft over the Pacific Ocean during the 1998 total solar eclipse. Although the IR data themselves are inconclusive because of the uncertainty in the precise central wavelengths of the narrowband filters during the eclipse, the consistency of t…
Hubble Space Telescope/Faint Object Spectrograph Spectroscopy of Spatially Resolved Narrow-Line Regions in the Seyfert 2 Galaxies NGC 2110 and NGC 5929
Simpson, Chris; Mulchaey, John S.; Ferruit, Pierre +3 more
We present the results of UV and optical Hubble Space Telescope/Faint Object Spectrograph spectroscopy of bright, extranuclear regions of line emission in the Seyfert galaxies NGC 2110 and NGC 5929. We have obtained spectra of the brightest region of the ``nuclear jet'' of NGC 2110 (75 pc from the nucleus) and of the southwest emission-line cloud …
Investigating the Metal Line Systems at Z=1.9 toward J2233-606 in the Hubble Deep Field South
Prochaska, Jason X.; Burles, Scott M.
The combination of Space Telescope Imaging Spectrograph (STIS) and optical spectroscopy with STIS imaging of the field surrounding J2233-606 affords a unique opportunity to study the physical nature of the quasar absorption-line systems. We present an analysis of the ionization state, chemical abundances, and kinematic characteristics of two metal…
On the determination of electron polytrope indices within coronal mass ejections in the solar wind
Gosling, J. T.
Electron temperature and density often appear to be negatively correlated with one another as a coronal mass ejection, CME, in the solar wind passes over a spacecraft at 1 AU and beyond. It has been suggested that this negative correlation within magnetic clouds, which form a subset of all CMEs, implies that the electron polytropic index for the p…