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Periodic outbursts in the peculiar X-ray binary 2S 0114+65.

Belloni, T.; Finley, J. P.; Cassinelli, J. P.

The peculiar X-ray binary system 2S 0114 + 65 has been observed by every X-ray satellite mission since its discovery by SAS 3 in 1977. A persistent feature of all the observations are outbursts on a time scale of about 3 hr. We have utilized the archival EXOSAT data, as well as published data and ROSAT all-sky survey data and show that the observe…

Absolute radius of an M giant.

Vogel, M.; Nussbaumer, H.; Monier, R.

We determine the absolute radius of an M2.4 III giant to be 75 solar radii, and we discuss and estimate the expected error. This value is found from the 1991 eclipse of the symbiotic binary EG And, observed in the UV. This system consists of a hot prewhite dwarf and an M giant. From two observed eclipses, separated by 6 orbital periods, we derive …

Lyman-Alpha Emission in Star-forming Galaxies: Low-Redshift Counterparts of Primeval Galaxies?

Calzetti, D.; Kinney, A. L.

We present UV plus optical spectra of three galaxies, Mrk 496, Mrk 357, Tol 1924-416, obtained by matching the size of the optical aperture with that of IUE. From the Hα/Hβ ratios, we estimate values of E(B - V)-extinction due to dust-for the two Markarian galaxies which are higher than those derived in previous works. We have used the new values …

The 0623+71 Bow Shock Nebula

Feibelman, W. A.; Hollis, J. M.; Wagner, R. M. +1 more

Deep radio continuum and deep narrow-band optical emission-line images showing the cataclysmic variable 0623 + 71 engulfed in a bow shock morphology are presented. The limb-brightened H-alpha, forbidden N II and 6 cm radio continuum emission regions define the global nebular morphology, extending to much greater spatial distances than the apex-con…

Detection of a Proton Beam during the Impulsive Phase of a Stellar Flare

Robinson, Richard D.; Shore, Steven N.; Woodgate, Bruce E. +2 more

A transient event consistent with the predicted temporal and spectral signatures of an energetic proton beam was detected in the impulsive phase of a small flare on the red dwarf star AU Microscopii. It consisted of a prominent increase in the flux in the red wing of Lyman-alpha near 1223 A, simultaneously with the peak of a flare observed in the …

The origin of complex organic ions in the coma of Comet Halley

Reme, H.; Korth, A.; Lin, R. P. +3 more

Heavy ion mass spectra were obtained in the inner coma of Comet Halley by the Giotto-PICCA instrument. Outside the cometary ionopause, where ≳2000 K ion temperatures limited the effective mass resolution to 3 amu, the spectra exhibit a series of distinct mass groups that are separated by a constant ≈ 15 amu and extend to at least 120 amu. We show …

The FAST HIPPARCOS Data Reduction Consortium: Overview of the Adopted Reduction Software

Badiali, M.; Cardini, D.; Emanuele, A. +38 more

This paper gives the main features of the data analysis methods adopted by FAST in the calibration and processing of the Hipparcos data. The structure of the data reduction software is described and the actual processing and evaluation is presented.

The Identification of Highly Ionized Metal Species in the Hot DA1 White Dwarf G191-B2B with the Hubble Space Telescope Faint Object Spectrograph

Sion, Edward M.; Bohlin, Ralph C.; Tweedy, Richard W. +1 more

On the Certification of AM Canum Venaticorum as a Cataclysmic Variable

Halpern, Jules P.; Raymond, John C.; Patterson, Joseph +1 more

The evidence that the peculiar faint blue star AM CVn (= HZ 29) is an ultrashort-period cataclysmic binary is reexamined. The existence of at least two noncommensurate short periods in the light curve, plus the recent discovery of the class of pulsating DB white dwarfs, suggests a need for reappraisal of the binary star model. New photometry and s…

The Quantative Assessment of UV Extinction Derived From IUE Data of Giants and Supergiants

Sembach, Kenneth R.; Cardelli, Jason A.; Mathis, John S.

It is shown here that the UV interstellar extinction towards hot luminous stars can be determined as accurately as for hot main-sequence stars. An atlas of IUE dereddened fluxes is presented for 13 lightly reddened stars within the 1160-3125 A range. The fluxes of these stars how absorption line strengths that allow a rather accurate determination…