Results 81 to 90 of about 4,978 (186)

Radio Astronomy with NASA’s Deep Space Network

open access: yesGalaxies
The Deep Space Network (DSN) is the spacecraft tracking and communication infrastructure for NASA’s deep space missions. At three sites, approximately equally separated in (terrestrial) longitude, there are multiple radio antennas outfitted with ...
T. Joseph W. Lazio, Stephen M. Lichten
doaj   +1 more source

Position determination of the Chang’e 3 lander with geodetic VLBI

open access: yesEarth, Planets and Space, 2019
We present results from the analysis of observations of the Chang’e 3 lander using geodetic Very Long Baseline Interferometry. The applied processing strategy as well as the limiting factors to our approach is discussed.
Grzegorz Klopotek   +9 more
doaj   +1 more source

Interferometric Images of the Starspot Evolution of ζ Andromedae

open access: yesThe Astrophysical Journal
The evolution of starspots of the giant primaries of RS CVn systems is typically detected indirectly with photometric and spectroscopic monitoring. These observations suggest slowly-evolving stellar surfaces and can constrain differential rotation as ...
Rachael M. Roettenbacher   +23 more
doaj   +1 more source

Time-lapse Very Long Baseline Interferometry Imaging of the Close Active Binary HR 1099

open access: yesThe Astrophysical Journal
We report multiepoch astrometric very long baseline interferometry observations of the chromospherically active binary HR 1099 (V711 Tau, HD 22468) at six epochs over 63 days using the Very Long Baseline Array at 22.2 GHz.
Walter W. Golay   +2 more
doaj   +1 more source

Very-Long-Baseline Interferometry [PDF]

open access: yes, 2017
A. Richard Thompson   +2 more
openaire   +1 more source

Interferometric Inference of Black Hole Spin from Photon Ring Size and Brightness

open access: yesThe Astrophysical Journal
The n = 1 photon ring is a full image of the astrophysical source around a black hole, produced by photons that execute n  ≈ 1 half-orbit around the event horizon on their way to an observer.
Joseph R. Farah   +3 more
doaj   +1 more source

Accessing a New Population of Supermassive Black Holes with Extensions to the Event Horizon Telescope

open access: yesThe Astrophysical Journal
The Event Horizon Telescope (EHT) has produced resolved images of the supermassive black holes (SMBHs) Sgr A* and M87*, which present the largest shadows on the sky.
Xinyue Alice Zhang   +8 more
doaj   +1 more source

CHIME/FRB Discovery and Localization of the Swift-observed FRB 20241228A

open access: yesThe Astrophysical Journal
On 2024 December 28, the Canadian Hydrogen Intensity Mapping Experiment (CHIME) FRB project detected the thus-far nonrepeating FRB 20241228A with a real-time signal-to-noise ratio of >50.
Alice P. Curtin   +28 more
doaj   +1 more source

A Very Long Baseline Interferometry Calibrator Grid at 600 MHz for Fast Radio Transient Localizations with CHIME/FRB Outriggers

open access: yesThe Astrophysical Journal
The Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst (CHIME/FRB) Project has a new very long baseline interferometry (VLBI) Outrigger at the Green Bank Observatory (GBO), which forms a 3300 km baseline with CHIME operating at 400–800 MHz ...
Shion Andrew   +18 more
doaj   +1 more source

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