Search Publications
Astrophysics in 2002
Aschwanden, Markus J.; Trimble, Virginia
This has been the Year of the Baryon. Some low temperature ones were seen at high redshift, some high temperature ones were seen at low redshift, and some cooling ones were (probably) reheated. Astronomers saw the back of the Sun (which is also made of baryons), a possible solution to the problem of ejection of material by Type II supernovae (in w…
Comparative Absorption and Emission Abundance Analyses of Nebulae: Ion Emission Densities for IC 418
Jenkins, Edward B.; Williams, Robert; Baldwin, Jack A. +1 more
Recent analyses of nebular spectra have resulted in discrepant abundances from CNO forbidden and recombination lines. We consider independent methods of determining ion abundances for emission nebulae, comparing ion emission measures with column densities derived from resonance absorption lines viewed against the central star continuum. Separate a…
On the Nature of Stars with Planets
Reid, I. Neill
We consider the metallicities and kinematics of nearby stars known to have planetary-mass companions in the general context of the overall properties of the local Galactic disk. We have used Strömgren photometry to determine abundances both for the extrasolar planet host stars and for a volume-limited sample of 486 F, G, and K stars selected from …
The 7.5 Magnitude Limit Sample of Bright Short-Period Binary Stars. I. How Many Contact Binaries Are There?
Rucinski, Slavek M.
A sample of bright contact binary stars (W UMa type or EW, and related: with β Lyr light curves, EB, and ellipsoidal, ELL-in effect, all but the detached, EA) to the limit of Vmax=7.5 mag is deemed to include all discoverable short-period (P<1 day) binaries with photometric variation larger than about 0.05 mag. Of the 32 systems in t…
The Progenitor of Supernova 1993J Revisited
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Kirshner, Robert P. +4 more
From Hubble Space Telescope images with 0.05" resolution, we identify four stars brighter than V=25 mag within 2.5" of SN 1993J in M81, which contaminated previous ground-based brightness estimates for the supernova progenitor. Correcting for the contamination, we find that the energy distribution of the progenitor is consistent with that of an ea…
A Hubble Space Telescope Snapshot Survey of Nearby Supernovae
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Modjaz, Maryam +4 more
We present photometry of 13 recent supernovae (SNe) recovered in a Hubble Space Telescope Snapshot program and tie the measurements to earlier ground-based observations in order to study the late-time evolution of the SNe. Many of the ground-based measurements are previously unpublished and were made primarily with a robotic telescope, the Katzman…
Possible Recovery of SN 1961V in Hubble Space Telescope Archival Images
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Li, Weidong
SN 1961V in NGC 1058 was originally classified by Fritz Zwicky as a ``Type V'' supernova. However, it has been argued that SN 1961V was not a genuine supernova, but instead the superoutburst of an η Carinae-like luminous blue variable star. In particular, Filippenko et al. used pre-refurbishment Hubble Space Telescope (HST) Wide Field Planetary Ca…
Autocorrelation Analysis of Hipparcos Photometry of Short-Period Be Stars
Percy, John R.; Hosick, JoAnne; Kincaide, Heather +1 more
We have used Hipparcos epoch photometry and a form of autocorrelation analysis to investigate the amplitude and timescale of the short-period variability of 82 Be stars, including 46 Be stars that were analyzed by Hubert & Floquet using Fourier and CLEAN analysis and 36 other Be stars that were suspected of short-period variability. Our method…
An Efficient Strategy to Select Targets for Gasdynamical Measurements of Black Hole Masses Using the Hubble Space Telescope
Filippenko, Alexei V.; Ho, Luis C.; Shields, Joseph C. +4 more
Gasdynamical studies using the Hubble Space Telescope are an integral component for future progress in the search for massive black holes in galactic nuclei. Here we present an extensive set of gas rotation curves obtained with the Space Telescope Imaging Spectrograph for the central regions of 23 disk galaxies. We find that the bulges of randomly…
Narrow-Angle Astrometry with the Space Interferometry Mission: The Search for Extrasolar Planets. I. Detection and Characterization of Single Planets
Sozzetti, A.; Lattanzi, M. G.; Casertano, S. +1 more
A decade after the publication of the Hipparcos Catalogue, the Space Interferometry Mission (SIM) will be capable of making selected high-precision astrometric measurements about 3 orders of magnitude more accurate than the Hipparcos survey. We present results from a detailed set of end-to-end numerical simulations of SIM narrow-angle astrometric …