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The Orbits of the Inner Neptunian Satellites from Voyager, Earth-based, and Hubble Space Telescope Observations
Jacobson, R. A.; Owen, W. M., Jr.
We present revised orbital elements for the six small Neptunian satellites discovered by Voyager 2. The elements have been determined from a fit to imaging data acquired by the Voyager 2 spacecraft and astrometric observations made at Earth-based observatories and by the Hubble Space Telescope. An assessment of the accuracy of the elements is prov…
FUSE Spectroscopy of the Large Magellanic Cloud Supernova Remnant N49
Blair, William P.; Raymond, John C.; Sankrit, Ravi
Strong C III λ977 and O VI λλ1032, 1038 emission lines are detected in Far Ultraviolet Spectroscopic Explorer (FUSE) spectra of N49, the brightest optical supernova remnant in the Large Magellanic Cloud. Shocks with velocities ranging from less than 130 to more than 180 km s-1 are responsible for these emission lines and are present ove…
The Stellar Content of the Polar Rings in the Galaxies NGC 2685 and NGC 4650A
Tikhonov, N. A.; Galazutdinova, O. A.; Hagen-Thorn, V. A. +3 more
We present the results of stellar photometry of polar ring galaxies NGC 2685 and NGC 4650A, using the archival data obtained with the Hubble Space Telescope's Wide Field Planetary Camera 2. Polar rings of these galaxies were resolved into ~800 and ~430 stellar objects in the B, V, and IC bands, a considerable part of which are blue supe…
Multiwavelength Properties of the X-Ray Sources in the Groth-Westphal Strip Field
Yamada, Toru; Griffiths, Richard E.; Sarajedini, Vicki +4 more
We summarize the multiwavelength properties of X-ray sources detected in the 80 ks XMM-Newton observation of the Groth-Westphal strip, a contiguous strip of 28 Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC2) images. Among the ~150 X-ray sources detected in the XMM-Newton field of view, 23 are within the WFPC2 fields. Ten spectroscopic…
Physical Structure of Planetary Nebulae. III. The Large and Evolved NGC 1360
Guerrero, Martín A.; Chu, You-Hua; Gruendl, Robert A. +1 more
NGC 1360 is a large planetary nebula (PN) without an obvious shell morphology. We have analyzed Hα images and high-dispersion echelle spectra of NGC 1360 in order to construct spatio-kinematic models and to determine its density distribution. The best-fit model indicates that NGC 1360 is a prolate ellipsoidal shell whose major axis is twice as lon…
Far-Ultraviolet Observations of RR Lyrae Stars in the Core of NGC 1851
Anderson, Scott F.; Homer, Lee; Margon, Bruce +1 more
There are extraordinarily few far-ultraviolet (FUV) observations of RR Lyrae stars in the literature. We present Hubble Space Telescope (HST) FUV (~1600 Å) imaging of the core of the globular cluster NGC 1851. Eleven new variables with light curves consistent with those of RR Lyrae stars are discovered, increasing the total number of RR Lyrae know…
Mid- and Far-Infrared Infrared Space Observatory Limits on Dust Disks around Millisecond Pulsars
Lazio, T. Joseph W.; Fischer, J.
We report 60 and 90 µm observations of seven millisecond pulsars with the Infrared Space Observatory. The pulsar PSR B1257+12 is orbited by three planets, and other millisecond pulsars may be orbited by dust disks that represent planets that failed to form or their residue. We do not detect any infrared emission from the seven pulsars in our…
Unveiling SU Aurigae in the Near-Infrared: New High Spatial Resolution Results Using Adaptive Optics
Ge, Jian; Chakraborty, Abhijit
We present new results on the circumstellar nebulosity around SU Aurigae, a T Tauri star of about 2 Msolar and 5 Myr old at 152 pc in the J, H, and K bands using high-resolution adaptive optics imaging (0.30") with the Penn State Near-IR Imager and Spectrograph at the 100 inch (2.5 m) Mount Wilson telescope. A comparison with Hubble Spa…
Far Ultraviolet Spectroscopic Explorer Spectroscopy of Absorption and Emission Lines from the Narrow-Line Seyfert 1 Galaxy NGC 4051
Brandt, W. N.; Kaspi, Shai; Elvis, Martin +2 more
We present three Far Ultraviolet Spectroscopic Explorer (FUSE) observations of the narrow-line Seyfert 1 galaxy NGC 4051. The most prominent features in the far-ultraviolet (FUV) spectrum are the O VI emission and absorption lines and the H I Lyman series absorption lines, which are detected up to the Lyman edge. We also identify weak emission fro…
Far-Ultraviolet Spectroscopy of Star-forming Regions in Nearby Galaxies: Stellar Populations and Abundance Indicators
Keel, William C.; Holberg, Jay B.; Treuthardt, Patrick M.
We present Far Ultraviolet Spectroscopic Explorer spectroscopy and supporting data for star-forming regions in nearby galaxies, to examine their massive-star content and explore the use of abundance and population indicators in this spectral range for high-redshift galaxies. New far-ultraviolet spectra are shown for four bright H II regions in M33…