Search Publications
Stellar Variability in the Metal-rich, Obscured Globular Cluster Terzan 5
Edmonds, Peter D.; Grindlay, Jonathan E.; Cohn, Haldan +1 more
We present the results of a search for variability in and near the core of the metal-rich, obscured globular cluster Terzan 5, using the near-infrared camera and multiobject spectrometer (NICMOS) on board the Hubble Space Telescope. This extreme cluster has approximately solar metallicity and a central density that places it in the upper few perce…
WFPC2 Imaging of Quasar Environments: A Comparison of Large Bright Quasar Survey and Hubble Space Telescope Archive Quasars
Hooper, Eric J.; Impey, Chris D.; Finn, Rose A.
We present Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC2) data on the large-scale environments of 16 0.39<z<0.51 quasars from the Large Bright Quasar Survey (LBQS). The LBQS quasars are representative of the radio-quiet population, and this is one of the first looks at their large-scale environments. We compare the LBQS e…
The Extreme-Ultraviolet Structure and Properties of a Newly Emerged Active Region
Gallagher, Peter T.; Phillips, Kenneth J. H.; Lee, Jeongwoo +2 more
The structure and properties of a newly emerged solar active region (NOAA Active Region 7985) are discussed using the Coronal Diagnostic Spectrometer (CDS) and the Extreme-Ultraviolet Imaging Telescope (EIT) on board the Solar and Heliospheric Observatory. CDS obtained high-resolution EUV spectra in the 308-381 Å and 513-633 Å wavelength ranges, w…
Ultraviolet Broad Absorption Features and the Spectral Energy Distribution of the Quasar PG 1351+64
Zheng, W.; Kriss, G. A.; Wang, J. X. +7 more
We present a moderate-resolution (~20 km s-1) spectrum of the mini-broad absorption line quasar (QSO) PG 1351+64 between 915 and 1180 Å, obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). Additional low-resolution spectra at longer wavelengths were also obtained with the Hubble Space Telescope (HST) and ground-based telesc…
Evidence for a Very Young Age of F Stars with Extrasolar Planets
Schultz, A. B.; Suchkov, A. A.
We assess the age of nine planet-bearing (PB) F stars by comparing their metallicity, Hp variability, brightness anomaly, and location in the color-magnitude diagram with the same parameters for the Hyades and field F stars. Combined evidence from these parameters suggests that the age of our PB F stars is not very much different from the age of t…
Detection of H2 Emission from Mira B in Ultraviolet Spectra from the Hubble Space Telescope
Wood, Brian E.; Karovska, Margarita; Hack, Warren
We present ultraviolet spectra of Mira's companion star from the Space Telescope Imaging Spectrograph (STIS) instrument on board the Hubble Space Telescope (HST). The companion is generally assumed to be a white dwarf surrounded by an accretion disk fed by Mira's wind, which dominates the UV emission from the system. The STIS UV spectrum is domina…
The Physics of the Solar Lower Transition Region
Doschek, G. A.; Mariska, J. T.
We discuss quiet-Sun intensities of spectral lines of O IV λ1401.16 and Si IV λ1402.77, their ratio, and their relation to expected properties of the lower solar transition region. The data consist of simultaneous measurements of the two line intensities for 16,988 pixels with spatial dimensions of 1" square obtained by the Solar Ultraviolet Measu…
A Critical Examination of Hypernova Remnant Candidates in M101. I. MF 83
Grebel, Eva K.; Lai, Shih-Ping; Ciardullo, Robin +2 more
The supernova remnant (SNR) candidate MF 83 in M101 is coincident with a very luminous X-ray source. Based on the high X-ray luminosity, it has been suggested that MF 83 is a ``hypernova remnant'' requiring an explosion energy about 2 orders of magnitude higher than normal supernovae. We have analyzed high-quality ground-based and Hubble Space Tel…
Preprotostellar Core Properties from Far-Infrared Observations
Langer, W. D.; Willacy, K.
We present the results of far-infrared ISOPHOT observations of the preprotostellar cores L1498, B133, and B68. Comparison of the 100 and 200 µm data suggest the presence of two dust temperatures along the line of sight. Using a two-temperature model that assumes a cold central core surrounded by a slightly warmer envelope, we have isolated t…
A Cepheid is No More: Hubble's Variable 19 in M33
Stanek, K. Z.; Macri, L. M.; Sasselov, D. D.
We report on the remarkable evolution in the light curve of a variable star discovered by Hubble in M33 and classified by him as a Cepheid. Early in the 20th century, the variable, designated as V19, exhibited a 54.7 day period, an intensity-weighted mean B magnitude of 19.59+/-0.23 mag, and a B amplitude of 1.1 mag. Its position in the period-lum…