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Saturn's Rings at True Opposition
French, Richard G.; Dones, Luke; Salo, Heikki +2 more
On 2005 January 14, the Saturn system was observed at true opposition with the planetary camera of the Wide Field Planetary Camera 2 (WFPC2) on the Hubble Space Telescope. This was the culmination of nearly a decade of similar UBVRI observations, yielding a uniform set of over 400 high spatial resolution and photometrically accurate radial profile…
The Distribution of Activity on the RS CVn-Type Star SZ Piscium
Henry, Gregory W.; Eaton, Joel A.
We use contemporaneous spectra and BV light curves to derive a model of the distribution of spots and active regions on the cooler component of SZ Psc for the 1993-1994 season. For that epoch, both spots and active regions were visible at all rotational phases of this chromospherically active star. The lack of large distortions of Doppler profiles…
Interstellar Absorption-Line Evidence for High-Velocity Expanding Structures in the Carina Nebula Foreground
Walborn, Nolan R.; Smith, Nathan; Gull, Theodore R. +3 more
The extreme, high-velocity interstellar absorption-line profiles toward η Carinae and 16 neighboring stars in Trumpler 16 are examined, including several new sight lines observed in the ultraviolet with the Hubble Space Telescope or in the optical from the Magellan and European Southern Observatories. No two sight lines are identical, but many vel…
Measuring the Balmer Jump and the Effective Gravity in FGK Stars
Bessell, Michael S.
It is difficult to accurately measure the effective gravity (logg) in late-type stars using broadband (e.g., UBV or SDSS) or intermediate-band (uvby) photometric systems, especially when the stars can cover a range of metallicities and reddenings. However, simple spectroscopic observational and data reduction techniques can yield accurate values f…
SIM PlanetQuest Key Project Precursor Observations to Detect Gas Giant Planets around Young Stars
Metchev, Stanimir; Prato, L.; Herbst, William +10 more
We present a review of precursor observing programs for the SIM PlanetQuest Key Project devoted to detecting Jupiter-mass planets around young stars. In order to ensure that the stars in the sample are free of various sources of astrometric noise that might impede the detection of planets, we have initiated programs to collect photometry, high-con…
Jitter Correction Algorithms for the COROT Satellite Mission: Validation with Test Bench Data and MOST On-Orbit Photometry
Auvergne, M.; Drummond, R.; Aerts, C. +5 more
We demonstrate the effectiveness and robustness of photometric correction algorithms for satellite pointing jitter in the upcoming space mission COROT, which will study asteroseismology and search for exoplanets. Two algorithms based on model-based estimation and decorrelation are tested in two ways: (1) with artificial light sources in the COROT …
Confirmation of New Planetary Nebulae in the Large Magellanic Cloud
Parker, Quentin A.; Reid, Warren A.; Shaw, Richard A.
We present Hubble Space Telescope (HST) images of new planetary nebulae (PNe) that were discovered in the Reid-Parker Anglo-Australian Observatory/UK Schmidt Telescope Hα survey of the Large Magellanic Cloud. These serendipitous observations from various HST programs yield independent confirmations of six PNe; one other detected nebula may also be…
FCAPT uvby Photometry of the mCP Stars HD 16545, HD 93226, HR 7575, and HR 8206
Adelman, Saul J.
The Four College Automated Photoelectric Telescope (FCAPT) obtained differential Strömgren uvby observations of the magnetic CP (mCP) stars HD 16545, HD 93226, HR 7575, and HR 8206. These are the first reported from the FCAPT. HD 16545, with its largest amplitudes (0.06 mag) being those in v and in b, has a period of 1.61926 days, close to its per…
Hubble Space Telescope Far-Ultraviolet Spectroscopy of the Dwarf Nova VW Hydri in Superoutburst
Sion, Edward M.; Merritt, Jason; Night, Christopher
We obtained three consecutive Hubble Space Telescope spectroscopic observations of a single superoutburst of the dwarf nova VW Hydri. The spectra cover the beginning, middle, and end of the superoutburst. All of the spectra are dominated by strong absorption lines due to C III (1175 Å), Lyα (1216 Å), N IV (1238 and 1242 Å), S II (1260-1565 Å), S I…
Crowded-Field Astrometry with SIM PlanetQuest. I. Estimating the Single-Measurement Astrometric Bias Arising from Confusion
Sridharan, R.; Allen, Ronald J.
The accuracy of position measurements of stellar targets with the future Space Interferometry Mission PlanetQuest (SIM) will be limited not only by photon noise and by the properties of the instrument (design, stability, etc.) and the overall measurement program (observing strategy, reduction methods, etc.), but also by the presence of other "conf…