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A Compact Supermassive Binary Black Hole System
We report on the discovery of a supermassive binary black hole system in the radio galaxy 0402+379, with a projected separation between the two black holes of just 7.3 pc. This is the closest black
We report the detection of periodic (p = 1.96 hr) bursts of extremely bright, 100% circularly polarized, coherent radio emission from the M9 dwarf TVLM 513-46546. Simultaneous photometric monitoring
A View through Faraday’s Fog. II. Parsec-Scale Rotation Measures in 40 Active Galactic Nuclei
Results from a survey of the parsec-scale Faraday rotation measure (RM) properties for 40 quasars, radio galaxies, and BL Lac objects are presented. Core RMs for quasars vary from approximately 500
Discovery of radio emission from the brown dwarf LP944-20
It is shown that LP944-20 has an unusually weak magnetic field in comparison to active M-dwarf stars, which might explain the previous null optical and X-rays results, as well as the strength of the radio emissions compared to those at X-ray wavelengths.
Constraining the Orbit of the Supermassive Black Hole Binary 0402+379
The radio galaxy 0402+379 is believed to host a supermassive black hole binary (SMBHB). The two compact core sources are separated by a projected distance of 7.3 pc, making it the most (spatially)
Faraday Rotation Measure Gradients from a Helical Magnetic Field in 3C 273
Using high-frequency (12-22 GHz) VLBA observations, we confirm the existence of a Faraday rotation measure gradient of ~500 rad m-2 mas-1 transverse to the jet axis in the quasar 3C 273. The gradient
Orbits, Distance, and Stellar Masses of the Massive Triple Star Sigma Orionis
We present interferometric observations of the sigma Orionis triple system using the CHARA Array, NPOI, and VLTI. Using these measurements, we spatially resolve the orbit of the close spectroscopic
Periodic Optical Variability of Radio-detected Ultracool Dwarfs
A fraction of very low mass stars and brown dwarfs are known to be radio active, in some cases producing periodic pulses. Extensive studies of two such objects have also revealed optical periodic
Optical Interferometric Observations of θ1 Orionis C from NPOI and Implications for the System Orbit
With the Navy Prototype Optical Interferometer (NPOI), the binary system θ1 Orionis C, the most massive member of the Trapezium, was spatially resolved over a time period extending from 2006 February
Constraining the Physical Parameters of the Circumstellar Disk of χ Ophiuchi
We present a numerical model describing a circularly symmetric gaseous disk around the Be star χ Ophiuchi. The model is constrained by long-baseline interferometric observations that are sensitive to