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NGC 1705. I. Stellar Populations and Mass Loss Via A Galactic Wind
Freeman, K. C.; Meurer, Gerhardt R.; Dopita, Michael A. +1 more
We present a detailed multi-waveband study of the galaxy NGC 1705. The data include optical and ultraviolet spectroscopy, optical and infrared photoelectric aperture photometry, narrowband and broadband images, H I spectra, and data from the IRAS point source catalog. NGC 1705 is shown to be a nearby (D~5 Mpc for H_0_ = 75 km s^-1^ Mpc^-1^) nuclea…
On the Nature of the Symbiotic Binary AX Persei
Mikolajewska, Joanna; Kenyon, Scott J.
Photometric and spectroscopic observations of the symbiotic binary AX Persei are presented. This system contains a red giant that fills its tidal lobe and transfers material into an accretion disk surrounding a low-mass main-sequence star. The stellar masses - 1 solar mass for the red giant and about 0.4 solar mass for the companion - suggest AX P…
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…
Dynamical Evolution Effects on the Hot Stellar Populations in Globular Clusters
Piotto, Giampaolo; Djorgovski, S.
Results of a study of FUV properties of Galactic globular clusters are presented. The spatially resolved spectra measured with the IUE satellite are used to find indications of color gradients in two clusters with the postcore-collapse (PCC) morphology, NGC 6752 and NGC 7099, but not in the case of NTGC 6093, a cluster with the classical King-mode…
The Ongoing Outburst of the Eclipsing Symbiotic Nova AS 296: The First 1200 days
Munari, Ulisse; Whitelock, Patricia A.; Gilmore, Alan C. +3 more
Ultraviolet, optical, and infrared photometry is reported for the symbiotic star AS 296, spanning the first 1200 d of its outburst which began in June 1988. The effects of the outburst were restricted to the wavelength interval 2200-7500 A. The progress of the event was followed through two maxima and two eclipses of the hot source by the M5 III c…
CCD observations of additional interstellar lines in stars associated with the VELA remnant and ETA Carinae nebulosity.
Wallerstein, George; Gilroy, Kalpana K.
Nine stars from the Vela Remnant and seven stars in the Eta Carinae complex are examined with CCD spectrograms with high signal-to-noise ratios for data regarding the optical interstellar lines. These data are supplemented by observations of objects with known high-velocity components and substantial interstellar Ti II lines. The CCD spectrograms …
Rotation and Transition Layer Emission in Cool Giants
Boehm-Vitense, Erika
Gray (1981, 1982) found that field giants with T(eff) less than about 5500 K experience a steep decrease in rotational velocities coupled with a decrease in transition layer emission. This decrease may be attributable to fast magnetic braking or to redistribution of angular momentum for rapidly increasing depths of the convection zones if these ro…
The Binary Cepheid BP Cir: A Test of Evolutionary Tracks
Arellano Ferro, A.; Evans, Nancy R.; Udalska, Joanna
IUE spectra of the system containing the Cepheid BP Cir are used to derive the magnitude difference between the two stars (Δ V = 1.88 ± 0.3 mag) and the spectral type of the companion (B6.OV). This is the first system yet encountered for which the standard Seaton reddening law is inappropriate. For BP Cir, a stronger 2200 Å bump than the standard …
CN Anomalies in Extremely Metal-Deficient Red Giants
Twarog, Bruce A.; Anthony-Twarog, Barbara J.; Shawl, Stephen J.
New photometric and UV spectroscopic data for the metal-deficient red giants CD -38 deg 245 and BD -18 deg 5550 are presented and discussed in light of recently noted photometric anomalies. From the IUE spectra it is aparent that the UV excess found in BD -18 deg 5550 is not the result of a hot companion. The IUE spectra, in conjunction with other…
The Luminosity of the Classical Cepheid T VUL
Evans, Nancy R.
The classical Cepheid T Vul has been discovered to have a hot companion on International Ultraviolet Explorer satellite spectra. The companion has a spectral type of A0.8 V. The absolute magnitude of the Cepheid determined from the companion is Mv = -3.43 mag. Because the companion is significantly fainter and less massive than the Ceph…