Search Publications
Photometric Study of the Kreutz Comets Observed by SOHO from 1996 to 2005
Hamilton, Douglas P.; A'Hearn, Michael F.; Lamy, Philippe +4 more
We present analysis of the photometry of more than 900 Kreutz comets observed by SOHO from 1996 to 2005. The Kreutz comets have "sungrazing" orbits with q≈ 1-2 R sun, high inclinations (i ≈ 143°), and periods of 500-1000 years. We find that they do not have a bimodal distance of peak brightness as previously reported, but instead peak f…
The Distance to NGC 1316 (Fornax A) from Observations of Four Type Ia Supernovae
Morrell, Nidia; Madore, Barry F.; Freedman, Wendy L. +15 more
The giant elliptical galaxy NGC 1316 (Fornax A) is a well-studied member of the Fornax Cluster and a prolific producer of Type Ia supernovae (SNe Ia), having hosted four observed events since 1980. Here, we present detailed optical- and near-infrared light curves of the spectroscopically normal SN 2006dd. These data are used, along with previously…
The Cluster AgeS Experiment (CASE). IV. Analysis of the Eclipsing Binary V69 in the Globular Cluster 47 Tuc
Thompson, I. B.; Dotter, A.; Kaluzny, J. +4 more
We use photometric and spectroscopic observations of the eclipsing binary V69-47 Tuc to derive the masses, radii, and luminosities of the component stars. Based on measured systemic velocity, distance, and proper motion, the system is a member of the globular cluster 47 Tuc. The system has an orbital period of 29.5d and the orbit is slightly eccen…
Pluto and Charon with the Hubble Space Telescope. II. Resolving Changes on Pluto's Surface and a Map for Charon
Stern, S. Alan; Young, Leslie A.; Buie, Marc W. +2 more
We present new imaging of the surface of Pluto and Charon obtained during 2002-2003 with the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) instrument. Using these data, we construct two-color albedo maps for the surfaces of both Pluto and Charon. Similar mapping techniques are used to re-process HST/Faint Object Camera (FOC) image…
HST and Spitzer Observations of the HD 207129 Debris Ring
Chen, Christine H.; Hines, Dean C.; Rieke, George H. +10 more
A debris ring around the star HD 207129 (G0V; d = 16.0 pc) has been imaged in scattered visible light with the ACS coronagraph on the Hubble Space Telescope (HST) and in thermal emission using MIPS on the Spitzer Space Telescope at λ = 70 µm (resolved) and 160 µm (unresolved). Spitzer IRS (λ = 7-35 µm) and MIPS (λ = 55-90 µ…
Outlying H II Regions in H I-Selected Galaxies
Freeman, K. C.; Ferguson, H. C.; Smith, R. C. +21 more
We present results from the first systematic search for outlying H II regions, as part of a sample of 96 emission-line point sources (referred to as ELdots-emission-line dots) derived from the NOAO Survey for Ionization in Neutral Gas Galaxies (SINGG). Our automated ELdot finder searches SINGG narrowband and continuum images for high equivalent wi…
X-ray Emission from Nitrogen-Type Wolf-Rayet Stars
Skinner, Stephen L.; Zhekov, Svetozar A.; Güdel, Manuel +2 more
We summarize new X-ray detections of four nitrogen-type Wolf-Rayet (WR) stars obtained in a limited survey aimed at establishing the X-ray properties of WN stars across their full range of spectral subtypes. None of the detected stars is so far known to be a close binary. We report Chandra detections of WR 2 (WN2), WR 18 (WN4), and WR 134 (WN6), a…
Spectroscopic Abundances and Membership in the Wolf 630 Moving Group
King, Jeremy R.; Bubar, Eric J.
The concept of kinematic assemblages evolving from dispersed stellar clusters has remained contentious since Eggen's initial formulation of moving groups in the 1960s. With high-quality parallaxes from the Hipparcos space astrometry mission, distance measurements for thousands of nearby, seemingly isolated stars are currently available. With these…
Pluto and Charon with the Hubble Space Telescope. I. Monitoring Global Change and Improved Surface Properties from Light Curves
Stern, S. Alan; Young, Leslie A.; Buie, Marc W. +2 more
We present new light-curve measurements of Pluto and Charon taken with the Advanced Camera for Surveys High-resolution Camera on the Hubble Space Telescope. The observations were collected from 2002 June to 2003 June at 12 distinct sub-Earth longitudes over a range of solar phase angle 0fdg36-1fdg74—a larger range than previously measured. The new…
Proper-motion Study of the Magellanic Clouds Using SPM Material
Casetti-Dinescu, Dana I.; Girard, Terrence M.; Korchagin, Vladimir I. +8 more
Absolute proper motions are determined for stars and galaxies to V = 17.5 over a 450 deg2 area that encloses both Magellanic Clouds. The proper motions are based on photographic and CCD observations of the Yale/San Juan Southern Proper Motion program, which span a baseline of 40 years. Multiple, local relative proper-motion measures are…