Search Publications
Missions
Journals
Publication Years
Chandra Discovery of a 300 Kiloparsec X-Ray Jet in the Gigahertz-peaked Spectrum Quasar PKS 1127-145
Elvis, Martin; Bechtold, Jill; Harris, D. E. +3 more
We have discovered an X-ray jet with Chandra imaging of the z=1.187 radio-loud quasar PKS 1127-145. In this paper we present the Chandra X-ray data, follow-up Very Large Array observations, and optical imaging using the Hubble Space Telescope Wide Field Planetary Camera 2. The X-ray jet contains 273+/-5 net counts in 27 ks and extends ~30" from th…
CHIANTI-An Atomic Database for Emission Lines. V. Comparison with an Isothermal Spectrum Observed with SUMER
Dere, K. P.; Landi, E.; Feldman, U.
CHIANTI is a database consisting of critically evaluated atomic data and transition probabilities necessary to analyze spectral observations of optically thin plasmas. Previous papers described the content of the database and compared it to a solar active region spectrum between 170 and 450 Å. The aim of the present paper is to compare CHIANTI pre…
A study of bright southern slowly pulsating B stars. II. The intrinsic frequencies
Aerts, C.; De Cat, P.
We present the results of detailed frequency analyses of a sample of thirteen confirmed slowly pulsating B stars. Our analysis is based on a combination of elaborate photometric and spectroscopic data-sets. The original sample consists of a mixture of five confirmed slowly pulsating B stars and twelve candidate slowly pulsating B stars discovered …
A Second Planet Orbiting 47 Ursae Majoris
Butler, R. Paul; Vogt, Steven S.; Fischer, Debra A. +2 more
Precise Doppler velocity measurements during 13 yr at Lick Observatory reveal the presence of two planets orbiting the star 47 UMa. The previously detected inner planet is confirmed by the newer velocities that yield a revised orbital period Pb=1089.0+/-2.9 days, Msini=2.54 MJ, and eccentricity eb=0.061+/-0.014. Th…
Dissecting the Homunculus nebula around Eta Carinae with spatially resolved near-infrared spectroscopy
Smith, Nathan
Near-infrared emission lines are unique diagnostics of the geometry, structure, kinematics, and excitation of the circumstellar ejecta of η Carinae, and give clues to the nature of its wind. The infrared spectrum is a strong function of position in η Car's nebula, with a mix of intrinsic and reflected emission. Molecular hydrogen traces cool gas a…
The Parallax and Proper Motion of RX J1856.5-3754 Revisited
van Kerkwijk, M. H.; Anderson, J.; Kaplan, D. L.
RX J1856.5-3754, a bright soft X-ray source believed to be the nearest thermally emitting neutron star, has commanded and continues to command intense interest from X-ray missions. One of the main goals is to determine the radius of this neutron star. An integral part of the determination is an accurate parallax. F. M. Walter analyzed Hubble Space…
The Cassini/Huygens Mission to the Saturnian System
Lebreton, Jean-Pierre; Matson, Dennis L.; Spilker, Linda J.
The international Cassini/Huygens mission consists of the Cassini Saturn Orbiter spacecraft and the Huygens Titan Probe that is targeted for entry into the atmosphere of Saturn's largest moon, Titan. From launch on October 15, 1997 to arrival at Saturn in July 2004, Cassini/Huygens will travel over three billion kilometers. Once in orbit about Sat…
Rotational velocities of A-type stars. I. Measurement of v sin i in the southern hemisphere
Royer, F.; Gerbaldi, M.; Faraggiana, R. +1 more
Within the scope of a Key Programme determining fundamental parameters of stars observed by HIPPARCOS, spectra of 525 B8 to F2-type stars brighter than V=8 have been collected at ESO. Fourier transforms of several line profiles in the range 4200-4500 Å are used to derive v sin i from the frequency of the first zero. Statistical analysis of the sam…
On the association between type II radio bursts and CMEs
Aurass, H.; Claßen, H. T.
Ground-based observations of metric (coronal) type II radio bursts are compared with observations of coronal mass ejections (CMEs) obtained by the LASCO coronagraph aboard SOHO and with decametric (interplanetary) type II bursts recorded by the WAVES instrument aboard Wind. The basic data sample comprises 63 metric type II radio bursts observed du…
A multi-epoch spectrophotometric atlas of symbiotic stars
Munari, U.; Zwitter, T.
A multi-epoch, absolute-fluxed spectral atlas extending from about 3200 to 9000 Å is presented for 130 symbiotic stars, including members of the LMC, SMC and Draco dwarf galaxies. The fluxes are accurate to better than 5% as shown by comparison with Tycho and ground-based photometric data. The spectra of 40 reference objects (MKK cool giant standa…