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Observations of Binary Stars with the Differential Speckle Survey Instrument. III. Measures below the Diffraction Limit of the WIYN Telescope
Howell, Steve B.; Ciardi, David R.; Horch, Elliott P. +2 more
In this paper, we study the ability of CCD- and electron-multiplying-CCD-based speckle imaging to obtain reliable astrometry and photometry of binary stars below the diffraction limit of the WIYN 3.5 m Telescope. We present a total of 120 measures of binary stars, 75 of which are below the diffraction limit. The measures are divided into two group…
The Solar Neighborhood. XXIII. CCD Photometric Distance Estimates of SCR Targets—77 M Dwarf Systems within 25 pc
Henry, Todd J.; Winters, Jennifer G.; Jao, Wei-Chun +3 more
We present CCD photometric distance estimates of 100 SCR (SuperCOSMOS RECONS) systems with µ >= 0farcs18 yr-1, 29 of which are new discoveries previously unpublished in this series of papers. These distances are estimated using a combination of new VRI photometry acquired at CTIO and JHK magnitudes extracted from 2MASS. The est…
Hubble Space Telescope WFC3 Early Release Science: Emission-line Galaxies from Infrared Grism Observations
Hathi, Nimish P.; Gardner, Jonathan P.; Mutchler, Max +29 more
We present grism spectra of emission-line galaxies (ELGs) from 0.6 to 1.6 µm from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope. These new infrared grism data augment previous optical Advanced Camera for Surveys G800L 0.6-0.95 µm grism data in GOODS-South from the PEARS program, extending the wavelength coverage well pas…
HST/ACS Observations of RR Lyrae Stars in Six Ultra-deep Fields of M31
Ferguson, H. C.; Rich, R. M.; Kalirai, J. S. +6 more
We present HST/ACS observations of RR Lyrae variable stars in six ultra-deep fields of the Andromeda galaxy (M31), including parts of the halo, disk, and giant stellar stream. Past work on the RR Lyrae stars in M31 has focused on various aspects of the stellar populations that make up the galaxy's halo, including their distances and metallicities.…
The Most Slowly Declining Type Ia Supernova 2001ay
Filippenko, Alexei V.; Kirshner, Robert P.; Matheson, Thomas +28 more
We present optical and near-infrared photometry, as well as ground-based optical spectra and Hubble Space Telescope ultraviolet spectra, of the Type Ia supernova (SN) 2001ay. At maximum light the Si II and Mg II lines indicated expansion velocities of 14,000 km s-1, while Si III and S II showed velocities of 9000 km s-1. Ther…
The Dust Properties of Two Hot R Coronae Borealis Stars and a Wolf-Rayet Central Star of a Planetary Nebula: In Search of a Possible Link
Sonneborn, G.; Gallagher, J. S.; Roman-Duval, J. +14 more
We present new Spitzer/IRS spectra of two hot R Coronae Borealis (RCB) stars, one in the Galaxy, V348 Sgr, and one lying in the Large Magellanic Cloud, HV 2671. These two objects may constitute a link between the RCB stars and the late Wolf-Rayet ([WCL]) class of central stars of planetary nebulae (CSPNe), such as CPD -56° 8032, that has little or…
Very Long Baseline Array Astrometric Observations of the Cassini Spacecraft at Saturn
Jacobson, Robert A.; Jones, Dayton L.; Dhawan, Vivek +5 more
The planetary ephemeris is an essential tool for interplanetary spacecraft navigation, studies of solar system dynamics (including, for example, barycenter corrections for pulsar timing ephemerides), the prediction of occultations, and tests of general relativity. We are carrying out a series of astrometric very long baseline interferometry observ…
SOHO/SWAN Observations of Short-period Spacecraft Target Comets
Bertaux, J. -L.; Combi, M. R.; Quémerais, E. +3 more
SWAN, the Solar Wind ANisotropies all-sky hydrogen Lyα camera on the Solar and Heliospheric Observatory spacecraft that makes all-sky images of interplanetary neutral hydrogen, has an ongoing campaign to make special observations of comets, both short- and long-period ones, in addition to the serendipitous observations of comets as part of the all…
A Volume-limited Photometric Survey of 114 γ Doradus Candidates
Henry, Gregory W.; Fekel, Francis C.; Henry, Stephen M.
We have carried out a photometric survey of a complete, volume-limited sample of γ Doradus candidates. The sample was extracted from the Hipparcos catalog and consists of 114 stars with colors and absolute magnitudes within the range of known γ Doradus stars and that also lie within a specified volume of 266,600 pc3. We devoted one year…
Properties of the H II Region Populations of M51 and NGC 4449 from Hα Images with the Advanced Camera for Surveys on the Hubble Space Telescope
Beckman, John E.; Gutiérrez, Leonel; Buenrostro, Valeria
We have used images from the Advanced Camera for Surveys on the Hubble Space Telescope in Hα, and in the neighboring continuum, to produce flux-calibrated images of the large spiral galaxy M51 and the dwarf irregular NGC 4449. From these images, we have derived the absolute luminosities in Hα, the areas, and the positions with respect to the galac…