Search Publications
Globular Cluster Luminosity Functions and the Hubble Constant from WFPC2 Imaging: The Dominant Group Elliptical NGC 5846
Forbes, Duncan A.; Brodie, Jean P.; Huchra, John
The Hubble Space Telescope's Wide Field and Planetary Camera 2 (WFPC2) has several advantages over ground-based observations for the study of globular cluster luminosity functions (GCLFs) and distance determination. Here we present WFPC2 data on the globular clusters associated with NGC 5846. This giant elliptical is the dominant galaxy in a small…
Kinematic Studies of Herbig-Haro Objects in the Orion Nebula
Hu, Xihai
Kinematic studies of most of the Herbig-Haro objects in M42 have been carried out. The proper motions of some of these objects have been determined through HST narrow band filter images taken four years apart; radial velocities of these objects have been obtained from high resolution échelle spectra taken at the Kitt Peak observatory using the Cou…
IUE Observations of Four Known/Suspected Magnetic Cataclysmic Variables
Szkody, Paula; Silber, Andrew
We present lUE spectra of the known magnetics (RX J0515+0105, H1752+081 [V2301 Oph]) and the suspected magnetics (H0459+246 and H0857-242 [VZ Pyx]). The flux limit for H0459+246 is consistent with either a magnetic system or a very large value for the reddening. The AM Her system with the longest orbital period (RX 10515+0105) has a very high UV l…
The Evolution of Red Galaxies in Clusters T z=0.5
Hoessel, John G.; Gunn, James E.; Oke, J. B.
A program was carried out at Palomar Observatory to study seven clusters of galaxies all at redshifts near 0.5. Observations consisted of g, r, i, and z broadband Gunn photometry using 4-shooter, and ultraviolet u and violet v photometry using a CCD photometer at the prime focus of the Hale 5 m telescope. The u and v filters reach rest wavelengths…
Charon/Pluto Mass Ratio Obtained with HST CCD Observations in 1991 and 1993
Null, G. W.; Owen, W. M., Jr.
We have analyzed Hubble Space Telescope Wide Field Camera observations of Pluto, Charon, and a reference star, acquired in 1991 and 1993, to observe Pluto's barycentric motion and determine the Charon/Pluto mass ratio, 0.124±0.008. Solution values for Charon orbital elements include the semimajor axis, 19662±81 km inclination, 96.57±0.24 deg; ecce…
Hubble Space Telescope Planetary Camera Images of NGC 1316 (Fornax A)
Faber, S. M.; Grillmair, C. J.; Ajhar, E. A. +7 more
We present HST Planetary Camera V and I band images of the central region of the peculiar giant elliptical galaxy NGC 1316. These high resolution images reveal that the central surface brightness rises sharply to 12.1 mag arcsec^-2^ in the I band and 13.5 mag arcsec^-2^ in the V band. The inner profile is well fit by a nonisothermal core model wit…
The Spectrophotometric Variability of the Galactic Luminous Blue Variables AG Carinae and HR Carinae from 1978 to 1995
Shore, Steven N.; Altner, Bruce; Waxin, Isabelle
We present a long-term multiwavelength spectrophotometric study of two representative Galactic luminous blue variables (LBVs), AG Carinae and HR Carinae. We find that the assumption of bolometric constancy leads independently to an extinction of E(B-V)=0.65±0.05 mag for AG Car and 1.0±0.l mag for HR Car. We derive a luminosity for AG Car, of order…
Multiwavelength Observations of Two Moderate Rotation RS CVn Systems: V815 Herculis and IM Pegasi
Neff, James E.; Dempsey, Robert C.; O'Neal, Douglas +1 more
Near-to-simultaneous ultraviolet and visual spectroscopy of two moderate v sin i RS CVn systems, V815 Herculis (v sin i=27 km s-1) and IM Pegasi (v sin i=24 km s-1), are presented along with contemporaneous UBV(RI)c photometry. These data were used to probe inhomogeneities in the chromospheres and photospheres, and the possib…
The Accretion Disk (Belt?) During the Quiescence of VW Hydri
Szkody, P.; Sion, E. M.; Huang, M. +2 more
We considered the contribution of an accretion disk to the UV spectrum of the dwarf nova (DN) VW Hydri during its quiescence, obtained with the Faint Object Spectrograph (FOS) on the Hubble Space Telescope (HST). Our analysis indicates that the UV emitting area of the disk is a ring of width 0.06 RWD, inclination angle i=60°, rotating w…
Spectroscopic Flickering in the WC8 Nucleus of the Planetary Nebula NGC 40
Bianchi, L.; Balick, Bruce; Rodgers, B. +2 more
The flat-topped profile of the nuclear C III λ5696 Å line in the WC8 nucleus of NGC 40 shows profile shape variations on time scales of hours. Relatively narrow intensity peaks and/or valleys (i.e., "features") appear first near the center of the 1400 km s-1 wide C III line. Over the next ≈3 hr the features slide toward either the red o…