Search Publications
White Dwarf Standard Stars: G191-B2B, GD 71, GD 153, HZ 43
Colina, Luis; Bohlin, Ralph C.; Finley, David S.
Three additional white dwarfs, GD 71, GD 153, and HZ 43, covering a wide range in effective temperature, have been observed with HST faint object spectrograph (FOS) to check the G191 -B2B white dwarf based absolute calibration of HST instruments. The FOS spectrophotometry of the three additional white dwarfs agree with model spectra to ∼2%. The FO…
HST/FOS Spectroscopy of ETA Carinae: The Star Itself, and Ejecta Within 0.3 Arcsec
Walborn, Nolan R.; Weigelt, Gerd; Humphreys, Roberta M. +4 more
Ground-based spectroscopy of η Car includes at least four components ABCD within a core region less than 0.4 across, and usually other material as well. Using the Hubble Space Telescope (HSTs) Faint Object Spectrograph (FOS), we have obtained separate data on component A and on B+C+D. Object A is found to be the central star; this is the fist time…
Evolution of the Symbiotic Binary System AG Draconis
Polidan, Ronald S.; Garcia, Michael R.; Mikolajewska, Joanna +2 more
We present an analysis of new and archival photometric and spectroscopic observations of the symbiotic star AG Draconis. This binary has undergone several 1 - 3 mag optical and ultraviolet eruptions during the past 15 years. Our combination of optical and ultraviolet spectroscopic data allow a more complete analysis of this system than in previous…
MG 0414+0534: A Dusty Gravitational Lens
Lawrence, C. R.; Elston, Richard; Turner, E. L. +1 more
The gravitational lens system MG 0414+0534 has an unexceptional four- image lensing geometry; however, the optical counterparts of the radio images are exceedingly red, with spectra unlike that of any previously observed active nucleus. New infrared spectra reveal broad Balmer lines at a redshift of 2.639+/-0.002. We use these spectra, in combinat…
Ellipticals with Kinematically Distinct Cores: WFPC1 Imaging of Nearby Ellipticals
Franx, Marijn; Illingworth, Garth D.; Forbes, Duncan A.
Ground-based spectroscopy of nearby ellipticals has revealed many to have cores that are kinematically distinct from the rest of the galaxy. Spectroscopic line analysis suggests that these kinematically distinct cores form a disk-like structure. A variety of mechanisms have been proposed to explain such cores. Here we present high resolution WFPC1…
Was Fritz Zwicky's "Type V" SN 1961V a Genuine Supernova?
Filippenko, Alexei V.; Ho, Luis C.; Barth, Aaron J. +4 more
In 1989, Goodrich and collaborators suggested that SN 1961V, a very peculiar Type II (Zwicky's "Type V") supernova, was not the final explosion of a star at the end of its life, but rather the giant eruption of a massive, luminous blue variable, like n Car. To test this hypothesis, we have used the Hubble Space Telescope to obtain optical images o…
HST Observations of the Stellar Population of the Globular Cluster W CEN
Casertano, Stefano; Elson, Rebecca A. W.; Gilmore, Gerard F. +1 more
We present a luminosity function for ∼4000 stars ∼3-5 half-mass radii from the center of the globular cluster co Cen (NGC 5139), based on images obtained with the Rubble Space Telescope's Planetary Camera as part of the Medium Deep Survey Key Project. The luminosity function (corrected for incompleteness) has a plateau at 5<MI<7, …
Far-UV Properties of the Nuclear Region of M31
King, Ivan R.; Stanford, S. Adam; Crane, Philippe
Comparison of the HST far-UV and visible images of the nucleus of M31 deepens the mystery of the two brightness peaks recently discovered by Lauer et al. (AJ, 106,1436(1993)]. At 175 nm the brightest point is the optically fainter peak (P2) that is close to the dynamical center. The very center of P2 has a UV upturn that is much greater than that …
Imaging of Low Redshift QSOs with WFPC2
Hutchings, J. B.; Morris, S. C.
Observations with the PC2 CCD of the Hubble Space Telescope are described of two bright QSOs of redshift ~0.3. 1403+434 is IR bright and radio quiet, and 2201+315 is radio loud with extended structure. Exposures were taken with the F702W and F555W filters. The images were deconvolved on their own and combined with 0.5 arcsec ground-based images. B…
Globular Clusters in Coma Galaxy NGC 4881
Holtzman, J. A.; Faber, S. M.; Grillmair, C. J. +8 more
We report HST-WFPC2 observations of the bright E0 galaxy NGC 4881, located about 18' north of the center of the Coma Cluster. Counts of globular clusters (GCs) were made both within the PC 1(f/28) frame and within the three WFC (f/13) frames. Attention was focused mainly on the PC1 data, in which faint GCs could be distinguished from noise spikes …