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Twin Peaks: IC 4329A and Arakelian 120
Marziani, P.; Sulentic, J. W.; Calvani, M.
New spectrophotometric observations of the Seyfert 1 galaxies IC 4329A and Arakelian 120 are presented. The low-ionization broad emission lines (as evidenced by Hβ) are strikingly similar. The so-called zero peak in the Balmer lines of these objects appears to be both broader than and blueshifted relative to the [O III] λλ4959, 5007 lines. It is a…
Studies of symbiotic stars. V. The dust-free yellow system He 2-467.
Munari, U.; Buson, L. M.
Results are presented of simultaneous photometric and spectroscopic observations of He2-467 in the infrared, optical, and satellite ultraviolet. It was found that the He2-467 star system consists of a G6 III star and a very hot (T of about 2 x 10 exp 5 K), luminous (L of about 5000 solar luminosities), and compact (R of about 0.06 solar radius) co…
Migrating optical depth enhancements in the UV wind lines of the WolfRayet star HD 93131.
Smith, L. J.; Prinja, R. K.
We report on the first identification of migrating opacity enhancements in the ultraviolet wind-lines of a Wolf-Rayet star. Systematic variability is identified in the He II lambda 1640 P Cygni profiles HD 93131 (WN 7), and is interpreted in terms of the formation and blueward migration of discrete absorption features. The properties of the featur…
Galileo and Ulysses dust measurements: Fz Venus to Jupiter
Grün, E.; Kissel, J.; Mann, I. +13 more
The Galileo and Ulysses spaceprobes carry two similar dust detectors through interplanetary space from Venus to Jupiter. We report here on impacts which correspond to dust particles above a mass threshold of about 10-13g for which we have complete records. Between December 1989 and January 1992 Galileo repeatedly traversed interplanetar…
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 central star of S 216.
Tweedy, R. W.; Napiwotzki, R.
Optical and high-resolution ultraviolet spectra of LS V + 46 21, the postulated central star of the large, nearby planetary nebula S 216, have been analyzed. From modeling the line profiles, this star is found to have an effective temperature of about 90,000 K, surface gravity log g of about 7, and a He:H ratio of about 0.01. These are as expected…
TYCHO Data Analysis. Overview of the Adopted Reduction Software and First Results
Snijders, M. A. J.; Grewing, M.; Pedersen, H. +15 more
In the Tycho project astrometric and photometric data of about 1,000,000 stars to a limit of B = 12 mag will be derived. The brightest 500,000 stars will obtain magnitudes in two colors BT and VT, the fainter 500,000 usually only one broad-band magnitude T. There is confidence that an accuracy will be achieved about 0.03 arcsec for positions and 0…
The Near-Ultraviolet Spectrum of Markarian 205
Jenkins, Edward B.; Schneider, Donald P.; Jannuzi, Buell T. +2 more
We report measurements of the absorption and of the emission lines between 1600 and 3200 A in the spectrum of the nearby AGN Markarian 205 (z = 0.071), which lies at a projected distance of 3 kpc (H_0_= 100 km s^-1^) from the nucleus of the nearby barred spiral galaxy NGC 4319 (z = 0.0047). The results were obtained using high-resolution (R = 1300…
Ultraviolet Imaging Telescope Observations of the Cygnus Loop
Jenkins, Edward B.; Gull, Theodore R.; Cheng, Kwang-Ping +8 more
Attention is given to UV images of a 40-arcmin field in the northeast part of the Cygnus Loop made by the Ultraviolet Imaging Telescope (UIT) during the Astro-1 mission in December 1990. The longest FUV (B5) exposure is compared with ground-based and X-ray observations and with models. It is inferred from SNR shock models that C IV 1550 A dominate…
Comparing Restored HST and VLA Imagery of R Aquarii
Hollis, J. M.; Yusef-Zadeh, F.; Dorband, J. E.
The maximum entropy method is applied to Hubble Space Telescope data taken of the R Aquarii binary system and its jet with the Faint Object Camera in order to restore an image in forbidden O III at 5007 A plagued by spherical aberration and detector saturation. These results are compared with 2-cm radio continuum imagery taken with the Very Large …