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New Proplyds, Outflows, Shocks, and a Reflection Nebula in M43 and the Outer Parts of the Orion Nebula
O'Dell, C. R.
Hubble Space Telescope WFPC2 images made as planned parallel observations have produced emission-line images of fields in the outer portions of the Orion Nebula and near the center of the companion H II region, M43. Examination of these images have uncovered three new bright proplyds and one silhouette proplyd. Two of the bright proplyds lie withi…
Bright X-Ray Transients in the Andromeda Galaxy Observed with Chandra and XMM-Newton
Trudolyubov, Sergey P.; Borozdin, Konstantin N.; Priedhorsky, William C.
We study three transient X-ray sources that were bright in the central region of the M31 galaxy in the year 2000. Observations with Chandra and XMM-Newton allowed us for the first time to derive X-ray light curves of transient sources in M31 suitable for studying their variability on a timescale of months and, in some periods, weeks. The three sou…
Lead, Tin, and Germanium in the Small Magellanic Cloud Main-Sequence B Star AV 304
Proffitt, Charles R.; Sansonetti, Craig J.; Reader, Joseph
We have determined the lead, tin, and germanium abundances of the early B main-sequence star AV 304 in the Small Magellanic Cloud (SMC) by using archival STIS/HST G140M spectral data to measure the Ge IV 1229.8 Å, Sn IV 1313.5 Å, and Pb IV 1313.1 Å resonance lines. We find [Ge/H]~-1.8, [Sn/H]~-1, and [Pb/H]~-0.15. We argue that finding a nearly so…
The eclipsing bursting X-ray binary EXO 0748-676 revisited by XMM-Newton
Haberl, F.; Bonnet-Bidaud, J. M.; Ferrando, P. +2 more
The bright eclipsing and bursting low-mass X-ray binary EXO 0748-676 has been observed at several occasions by XMM-Newton during the initial calibration and performance verification (CAL/PV) phase. We present here the results obtained from observations with the EPIC cameras. Apart from several type-I X-ray bursts, the source shows a high degree of…
Coordinated observations of the quiet Sun transition region using SUMER spectra, TRACE images and MDI magnetograms
Innes, D. E.
The relationship between the transition region ultraviolet emission and the underlying magnetic field is explored through a detailed analysis of SUMER SI IV line profiles, TRACE C IV, continuum and 171 Å intensities, and MDI high resolution magnetic field measurements. The observations track a narrow area of quiet Sun near disk center over a perio…
Tomographic Separation of Composite Spectra. VII. The Physical Properties of the Massive Triple System HD 135240 (δ Circini)
Gies, Douglas R.; Kaper, L.; Fullerton, A. W. +5 more
We present the results of a radial velocity study of the massive, double-lined, O binary HD 135240 based primarily on UV spectroscopy from the International Ultraviolet Explorer. Cross-correlation methods indicate the presence of a third stationary spectral line component which indicates that the system is a triple consisting of a central 3.9 day …
Uranus' Apparent Seasonal Variability in 25 HST Filters
Karkoschka, Erich
Hubble Space Telescope (HST) images of Uranus taken in 1997 reveal that Voyager's view of the southern hemisphere was not representative of the rest of the planet. The banded structure with hemispherical asymmetry, presented in 25 filters between 0.27 and 2.03 µm wavelength, caused Uranus' full disk to darken by as much as 35% between 1985 a…
X-ray absorption in Seyfert 2 galaxies
Perola, G. C.; Fiore, F.; Guainazzi, M. +1 more
We have studied the correlation among X-ray absorption, optical reddening and nuclear dust morphology in Seyfert 2 galaxies. Two main conclusions emerge: (i) the Balmer decrement and the amount of X-ray absorption are anticorrelated over a wide range of column density, 1021<~NH<~1024cm- 2 - the cor…
M2000: An astrometric catalog in the Bordeaux Carte du Ciel zone +11degr <= delta <= +18degr
Ducourant, C.; Soubiran, C.; Le Campion, J. -F. +11 more
During four years, systematic observations have been conducted in drift scan mode with the Bordeaux automated meridian circle in the declination band +11degr <= delta <= +18degr . The resulting astrometric catalog includes about 2.3x 106 stars down to the magnitude limit VM=16.3. Nearly all stars (96%) have been observe…
A Combined Hipparcos and Multichannel Astrometric Photometer Study of the Proposed Planetary System of ρ Coronae Borealis
Han, Inwoo; Gatewood, George; Black, David C.
Hipparcos and Multichannel Astrometric Photometer (MAP) observations of ρ Coronae Borealis independently display astrometric motion at the period of the proposed ``extrasolar planetary'' companion to the star. Individual least-squares fits to each astrometric data set yield independent estimates of the semimajor axis, inclination, and node angle t…