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Sulfur Abundance in the Slow Solar Wind
Wurz, P.; Ipavich, F. M.; Opitz, A. +2 more
Using 4 years of data from the Mass Time-of-Flight and Proton Monitor, two CELIAS sensors on board SOHO, we report the sulfur abundances in comparison to magnesium and calcium (two low first ionization potential elements) for the slow solar wind, and for the first time we measure the sulfur isotopic abundance ratio. For the period in which the pro…
Evidence for the Evolution of Young Early-Type Galaxies in the GOODS/CDF-S Field
Mobasher, Bahram; Goudfrooij, Paul; Puzia, Thomas H.
We have developed an efficient photometric technique for identifying young early-type galaxy candidates using a combination of photometric redshifts, spectral-type classification, and optical/near-infrared colors. Applying our technique to the GOODS HST ACS and VLT ISAAC data, we have selected a complete and homogeneous sample of young elliptical …
A Silver Anniversary Observation of the X-Ray-Luminous SN 1978K in NGC 1313
Schlegel, E. M.; Lenz, E.
We describe the results of a 2003 Chandra ACIS-I observation of SN 1978K. The spectrum shows little flux below 0.6 keV, in contrast to the 2002 Chandra ACIS-S observation, which showed flux to 0.4 keV. Fitting the ACIS-I spectrum alone leads to two solutions depending on the value of the column density. A joint fit using a dual thermal plasma mode…
The Spectroscopic and Astrometric Orbits of HR 672
Pourbaix, D.; Fekel, Francis C.; Williamson, Michael
From a very extensive set of radial velocities obtained at Fairborn Observatory we have computed a new spectroscopic orbit for HR 672. This binary has an orbital period of 93.290 days and an eccentricity of 0.5249. The greatly improved orbital elements have been incorporated into a new astrometric orbit, which has an inclination of 110°, from Hipp…
Evidence for Three Subpopulations of Globular Clusters in the Early-Type Poststarburst Shell Galaxy AM 0139-655
Schweizer, François; Goudfrooij, Paul; Puzia, Thomas +2 more
We present deep Hubble Space Telescope ACS images of the poststarburst shell galaxy AM 0139-655. We find evidence for the presence of three distinct globular cluster (GC) subpopulations associated with this galaxy: a centrally concentrated young population (~0.4 Gyr), an intermediate-age population (~1 Gyr), and an old, metal-poor population simil…
Keck HIRES Spectroscopy of Candidate Post-T Tauri Stars
Deliyannis, Constantine P.; Soderblom, David R.; King, Jeremy R. +2 more
We use high signal-to-noise ratio (~150-450), high-resolution (R ~ 45,000) Keck HIRES spectroscopy of 13 candidate post-T Tauri stars (PTTs) to derive basic physical parameters, lithium abundances, and radial velocities. We place our stars in the Mv-Teff plane for use in determining approximate ages from pre-main-sequence iso…
Hipparcos Astrometric Orbit and Evolutionary Status of HR 6046
Torres, Guillermo
The previously known, 6 yr single-lined spectroscopic binary HR 6046 has been speculated in the past to contain a compact object as the secondary. A recent study has redetermined the orbit with great accuracy and shown that the companion is an evolved but otherwise normal star of nearly identical mass to the primary, which is also a giant. The bin…
Chromospherically Active Stars. XXVI. The Double-Lined Late-Type Binary HD 19485 = WZ Arietis
Bolton, C. T.; Fekel, Francis C.
We have used spectroscopic observations to determine the orbital elements and some basic properties of the double-lined spectroscopic binary HD 19485 = WZ Ari. The orbital period is 6.247854 days, and the orbit is circular. The G5 V primary and K0 V secondary are chromospherically active. One star or possibly both are synchronously rotating. Based…
Searching for Low-Mass Binary Companions in M35 Using the Fine Guidance Sensors of the Hubble Space Telescope
Harrison, T. E.; McArthur, Barbara; McNamara, B. J.
The Hubble Space Telescope Fine Guidance Sensors data on 23 stars in the intermediate-age cluster M35 having B-V<0.5 (~F7 V) are analyzed to test whether binary periods, separations, and masses can be estimated by measuring periodic variations in the residuals of their internal proper motions. Of the 23 stars examined, 4 appear to possess a per…