Search Publications
Interferometric Astrometry of the Detached White Dwarf-M Dwarf Binary Feige 24 Using HST Fine Guidance Sensor 3: White Dwarf Radius and Component Mass Estimates
Hemenway, P. D.; Jefferys, W. H.; Nelan, E. +14 more
With Hubble Space Telescope Fine Guidance Sensor 3 we have determined a parallax for the white dwarf-M dwarf interacting binary, Feige 24. The white dwarf (DA) component has an effective temperature Teff~56,000 K. A weighted average with past parallax determinations (πabs=14.6+/-0.4 mas) narrows the range of possible radius v…
ASCA Observation of the Quiescent X-Ray Counterpart to SGR 1627-41
Hurley, K.; Sugizaki, M.; Kouveliotou, C. +9 more
We present a 2-10 keV ASCA observation of the field around the soft gamma repeater SGR 1627-41. A quiescent X-ray source, whose position is consistent both with that of a recently discovered BeppoSAX X-ray source and with the Interplanetary Network localization for this soft gamma repeater, was detected in this observation. In 2-10 keV X-rays, the…
Resolved stellar populations of super-metal-rich star clusters in the bulge of M 31
Magain, P.; Jablonka, P.; Sarajedini, A. +3 more
We have applied the MCS image deconvolution algorithm (Magain et al. 1998) to HST/WFPC2 V, I data of three M 31 bulge globular clusters (G170, G177, and G198) and control fields near each cluster. All three clusters are clearly detected, with an increase in stellar density with decreasing radius from the cluster centers; this is the first time tha…
The Asymmetric Coma of Comets. I. Asymmetric Outgassing from the Nucleus of Comet 2P/Encke
Festou, M. C.; Barale, O.
Very little is known about how outgassing regions are distributed over the nucleus of comets. In periodic comets, active regions are believed to be few and of small extent. Since periodic comets are notorious for their lack of (small) solid particles that efficiently scatter sunlight, we try to find traces of the existence of production sites by e…
UV light curves of thermonuclear supernovae
Sorokina, E. I.; Blinnikov, S. I.
Ultraviolet light curves are calculated for several thermonuclear supernova models using a multifrequency radiation hydrodynamic code. It is found that Chandrasekhar-mass models produce very similar light curves both for detonation and deflagration. Sub-Chandrasekhar-mass models essentially differ from ``normal'' Chandrasekhar ones regarding behav…
High-Resolution Study of Associated C IV Absorption Systems in NGC 5548
Srianand, R.
We present the results of a careful analysis of associated absorption systems toward NGC 5548. Most of the well-resolved narrow components in the associated system, defined by the Lyα, C IV, and N V profiles, show velocity separation similar (to within 10 km s-1) to the C IV doublet splitting. We estimate the chance probability of the o…
Recent Observations of the Heliospheric Magnetic Field at Ulysses: Return to Low Latitude
Balogh, A.; Tsurutani, B. T.; Smith, E. J. +2 more
Ulysses recently completed a second slow latitude scan of the northern heliosphere, a descent from 80.2°N in July 1995 to the solar equator in December 1997. These recent magnetic field observations complement those from the south hemisphere and reveal new features as well as the effect of the changing solar cycle. Five topics are emphasized in th…
RX J1313.2-3259, a missing link in CV evolution?
Gänsicke, B. T.; Beuermann, K.; de Martino, D. +1 more
We present low-state IUE spectroscopy of the ROSAT-discovered polar RX J1313.2-3259. The SWP spectrum displays a broad Lyalpha absorption profile, which can be fitted with a two-temperature model of a white dwarf of T_wd=15 000 K with a hot spot of T_spot=34 000 K which covers f ~ 0.01 of the white dwarf surface. The white dwarf temperature is aty…
The potential of solar high-degree modes for structure inversion
Christensen-Dalsgaard, J.; Basu, Sarbani; Rabello-Soares, M. C. +1 more
It is likely that precise and reliable frequencies of high-degree modes will soon be available from the SOI/MDI experiment. Here we examine the ability of such modes (with l>300) to resolve the solar structure in the near-surface region. In particular, we investigate inversions to determine the adiabatic exponent Γ1 as a test of the …
Shock excited far-infrared molecular emission around T Tau
White, G. J.; Palla, F.; Pezzuto, S. +9 more
The first complete far-infrared spectrum of T Tau has been obtained with the LWS spectrometer on-board the Infrared Space Observatory (ISO), which detected strong emission from high-J (J=14-25) CO, para- and ortho-H_2O and OH transitions over the wavelength range from 40 to 190 mu m. In addition the [OI]63mu m, [OI]145mu m and [CII]158mu m atomic …