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An active K0 IV-V star and a hot white dwarf (EUVE J0702+129) in a wide binary.
Doyle, J. G.; Christian, D. J.; Mathioudakis, M. +1 more
We present far ultraviolet and optical spectroscopy of the Extreme Ultraviolet Explorer (EUVE) survey source EUVE J0702+129 revealing a composite K0 star plus DA white dwarf spectrum. The International Ultraviolet Explorer spectra show continuum emission from a hot white dwarf (Teff=30-40,000K) and a rising contribution from the K0 star at λ>25…
Detection of a Satellite Orbiting The Nucleus of Comet Hale–Bopp (C/1995 O1)
Sekanina, Z.
This paper reports on the detection of a satellite around the principal nucleus of comet Hale-Bopp. As shown elsewhere, a successful morphological model for the comet's dust coma necessitates the postulation of overlapping jet activity from a comet pair. The satellite has been detected digitally on images taken with the Hubble Space Telescope's Wi…
Wind variability of B supergiants. II. The two-component stellar wind of γ Arae.
Howarth, I. D.; Massa, D.; Prinja, R. K. +2 more
The stellar wind of the rapidly rotating early-B supergiant, γ Ara, is studied using time series, high-resolution IUE spectroscopy secured over ~6 days in 1993 March. Results are presented based on an analysis of several line species, including N V, C IV, Si IV, Si III, C II, and Al III. Comparisons of the time-averaged wind line morphology of γ A…
The Joint Science Operations Centre
Chaizy, P. A.; Dimbylow, T. G.; Hapgood, M. A. +4 more
ISO-SWS Observations of NGC 1068
Lutz, D.; Genzel, R.; Sturm, E. +2 more
We present a first analysis of 2.4-45µm spectra of NGC 1068 obtained with the Short Wavelength Spectrometer SWS on board the Infrared Space Observatory ISO. The measured fine-structure line fluxes can be fit successfully by a simple photoionization model invoking an EUV bump in the ionizing continuum, similar to the case of the Circinus galaxy. Di…
The Distance to the Hyades Cluster Based on Hubble Space Telescope Fine Guidance Sensor Parallaxes
Kozhurina-Platais, V.; Benedict, G. F.; Franz, O. G. +24 more
Trigonometric parallax observations made with the Hubble Space Telescope (HST) Fine Guidance Sensor (FGS) 3 of seven Hyades members in six fields of view have been analyzed along with their proper motions to determine the distance to the cluster. Knowledge of the convergent point and mean proper motion of the Hyades is critical to the derivation o…
Comparison of IUE and HST diagnostics of the Jovian Aurorae
Livengood, T.; Harris, W. M.; Prangé, R. +2 more
Analysis of international ultraviolet explorer (IUE) and Voyager ultraviolet spectrometer (UVS) spectra of the Jovian auroral emission indicates that the Jovian auroral brightness is modulated in longitude (brighter near 180° in the north and 20° in the south) and that there is a color ratio asymmetry associated with this brightening. The purpose …
The dynamical mass of the beat cepheid Y carinae and stellar opacities.
Bohm-Vitense, E.; Evans, N. R.; Carpenter, K. +3 more
The beat Cepheid, Y Carinae A, has a B9 V companion, Y Car B. The primary period P0 of the Cepheid is 3.64 days and the secondary, P1, is 2.56 days. Its period ratio P1/P0 is thus 0.703. Y Car is the only beat Cepheid known to be a binary and thus offers us the unique opportunity to determine the dynamic…
The Mount Wilson Halo Mapping Project 1975-1985 I: The UBV(RI)_M_W Photometric System Compared with Other Standard Systems: The Adopted Trigonometric HR Diagram in (R-I)_M_W and (V-I)_M_W
Sandage, A.
Photometry of stars is described that defines a UBV(RI)_M_W photometric system, established between 1975 and 1980 using the Mount Wilson 60-inch and 100-inch reflectors. The MW natural system has been reduced to the UBV(RI)_C Cape-Cousins system by linear equations for stars hotter than M0. Strong non-linear color and magnitude equations exit in R…
Particle acceleration at corotating reverse shocks in the southern hemisphere: Ulysses results
Balogh, A.; Forsyth, R. J.; Desai, M. I. +3 more
We have correlated the ∼1 MeV proton intensity (J) measured at corotating reverse shocks detected by Ulysses in the southern hemisphere with two parameters that characterise the strength of the shock. Between 6°-29°S J is essentially independent of the shock strength, whereas between 29°-41°S J is well correlated with the same. The poor correlatio…