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Related papers: Speckle Interferometry at the U.S. Naval Observato…

200 papers

Radial velocity (RV) monitoring of solar-type visual binaries has been conducted at the CTIO/SMARTS 1.5-m telescope to study short-period systems. Data reduction is described, mean and individual RVs of 163 observed objects are given. New…

Solar and Stellar Astrophysics · Physics 2015-11-05 Andrei Tokovinin

We report the results of speckle-interferometric observations of 109 high proper-motion metal-poor stars made with the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. We resolve eight objects --…

Astrophysics · Physics 2007-07-20 D. A. Rastegaev , Yu. Yu. Balega , E. V. Malogolovets

The Infrared Space Observatory (ISO) observed the BL Lac object PKS 2155-304 16 times from 1996, May 7 to June 8, with both the ISOCAM camera and the ISOPHOT photometer, as part of a more general multiwavelength campaign. Two additional…

Astrophysics · Physics 2007-05-23 E. Bertone , G. Tagliaferri , G. Ghisellini , A. Treves , L. Chiappetti , L. Maraschi

Ten galaxy clusters, with redshift ranging from 0.2 to 1, have been observed with the ISO camera in the two bands LW2 and LW3 (centered respectively at 6.75 and 15 microns). We present a first analysis for three of these clusters at…

Astrophysics · Physics 2007-05-23 Dario Fadda , David Elbaz

The third US Naval Observatory (USNO) CCD Astrograph Catalog, UCAC3 was released at the IAU General Assembly on 2009 August 10. It is a highly accurate, all-sky astrometric catalog of about 100 million stars in the R = 8 to 16 magnitude…

Instrumentation and Methods for Astrophysics · Physics 2015-05-18 Norbert Zacharias

We report that the Sloan Digital Sky Survey quasar SDSS J165043.44+425149.3 is gravitationally lensed into two images, based on observations obtained with the WIYN 3.5 m telescope at the Kitt Peak National Observatory. The lensed quasar, at…

Astrophysics · Physics 2016-08-30 Nicholas D. Morgan , Jeffrey A. Snyder , Louis H. Reens

We present a program of routine lunar occultations, at optical and near-IR wavelengths, recently started at the 1.5m Spanish telescope at the Calar Alto Observatory. Both a CCD and an infrared array detector are used. The program is aimed…

Astrophysics · Physics 2007-05-23 O. Fors , A. Richichi , J. Nunez , A. Prades

We present 1103 trigonometric parallaxes and proper motions from the United States Naval Observatory (USNO) Robotic Astrometric Telescope (URAT) observations taken at the Naval Observatory Flagstaff Station (NOFS) over a 3 year period from…

Solar and Stellar Astrophysics · Physics 2016-06-08 Charlie Finch , Norbert Zacharias

We have conducted the first systematic search for interday variability in a large sample of extragalactic radio sources at 15 GHz. From the sample of 1158 radio-selected blazars monitored over a $\sim$10 year span by the Owens Valley Radio…

Orbits of 44 close and fast visual binaries are computed using the latest speckle observations; 23 orbits are determined for the first time, the rest are revisions, some quite substantial. Six combined orbits use radial velocities. The…

Solar and Stellar Astrophysics · Physics 2017-08-30 Andrei Tokovinin

We report the discovery of a unique gravitational lens system, SDSSJ2222+2745, producing five spectroscopically confirmed images of a z_s=2.82 quasar lensed by a foreground galaxy cluster at z_l=0.49. We also present photometric and…

We present the results of a photometric CCD monitoring of the gravitational lens system UM 673, that took place from 1995 to 2000. In total, the doubly-imaged quasar was observed in the R-band during 29 photometric nights, using optical…

Astrophysics · Physics 2009-11-06 D. Sinachopoulos , Th. Nakos , P. Boumis , E. van Dessel , M. Burger , P. Rodriguez-Gil

Refractive scintillation effects are powerful techniques for discriminating between different models proposed for the electron density fluctuation spectrum in the ISM. Data from our long-term scintillation study of 18 pulsars in the DM…

Astrophysics · Physics 2009-10-31 N. D. Ramesh Bhat , Yashwant Gupta , A. Pramesh Rao

Wide separation lensing statistics offer information about the density profile and abundance of dark halos. Recently a possible discovery of six quasar pairs, which may be lensed multiple images, was reported by Miller et al. (2003,…

Astrophysics · Physics 2009-11-07 Masamune Oguri

We conducted speckle imaging observations of 53 stellar systems that were members of long-term radial velocity (RV) monitoring campaigns and exhibited substantial accelerations indicative of planetary or stellar companions in wide orbits.…

We present the first on-sky results from an ultra-low-readout-noise Skipper CCD focal plane prototype for the SOAR Integral Field Spectrograph (SIFS). The Skipper CCD focal plane consists of four 6k x 1k, 15 $\mu$m pixel, fully-depleted,…

We present accurate multiwavelength UBVI time series data of the LMC cluster Reticulum. Data cover a time interval of ~ 6 yr and have been collected with SUSI1/2 and SOFI at NTT/ESO. For each band we collected approximately 30 short/long…

We present the first CCD variability study of the Draco dwarf spheroidal galaxy. The data were obtained with the FLWO 1.2 m telescope on 22 nights, over a period of 10 months, covering a 22 x 22 arcmin field centered at RA=17:19:57.5,…

Astrophysics · Physics 2008-11-26 A. Z. Bonanos , K. Z. Stanek , A. H. Szentgyorgyi , D. D. Sasselov , G. A. Bakos

We present the first speckle interferometric observations of R CrB, the prototype of a class of peculiar stars which undergo irregular declines in their visible light curves. The observations were carried out with the 6m telescope at the…

We have measured the diameters of the Cepheid variables delta Cephei (18 nights) and eta Aquilae (11 nights) with the Navy Prototype Optical Interferometer. The primary results of these observations are the mean angular diameters…