Results 1 to 10 of about 1,474,036 (268)

First Observations of the Brown Dwarf HD 19467 B with JWST

The Astrophysical Journal, 2023
We observed HD 19467 B with JWST’s NIRCam in six filters spanning 2.5–4.6 μ m with the long-wavelength bar coronagraph. The brown dwarf HD 19467 B was initially identified through a long-period trend in the radial velocity of the G3V star HD 19467.
Alexandra Z. Greenbaum, Jorge Llop-Sayson, Ben W.P. Lew, Geoffrey Bryden, Thomas L. Roellig, Marie Ygouf, B. J. Fulton, Daniel R. Hey, Daniel Huber, Sagnick Mukherjee, Michael Meyer, Jarron Leisenring, Marcia Rieke, Martha Boyer, Joseph J. Green, Doug Kelly, Karl Misselt, Eugene Serabyn, John Stansberry, Laurie E. U. Chu, Matthew De Furio, Doug Johnstone, Joshua E. Schlieder, Charles Beichman   +23 more
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Detecting Exoplanets Closer to Stars with Moderate Spectral Resolution Integral-field Spectroscopy

The Astronomical Journal, 2023
While radial velocity surveys have demonstrated that the population of gas giants peaks around 3 au, the most recent high-contrast imaging surveys have only been sensitive to planets beyond ∼10 au.
Shubh Agrawal, Jean-Baptiste Ruffio, Quinn M. Konopacky, Bruce Macintosh, Dimitri Mawet, Eric L. Nielsen, Kielan K. W. Hoch, Michael C. Liu, Travis S. Barman, William Thompson, Alexandra Z. Greenbaum, Christian Marois, Jenny Patience   +12 more
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Searching for Planets Orbiting Fomalhaut with JWST/NIRCam

The Astronomical Journal, 2023
We report observations with the JWST/NIRCam coronagraph of the Fomalhaut ( α PsA) system. This nearby A star hosts a complex debris disk system discovered by the IRAS satellite.
Marie Ygouf, Charles A. Beichman, Jorge Llop-Sayson, Geoffrey Bryden, Jarron M. Leisenring, András Gáspár, John E. Krist, Marcia J. Rieke, George H. Rieke, Schuyler Grace Wolff, Thomas L. Roellig, Kate Su, Kevin N. Hainline, Klaus W. Hodapp, Thomas P. Greene, Michael R. Meyer, Douglas M. Kelly, Karl Misselt, John Stansberry, Martha Boyer, Doug Johnstone, Scott Horner, Alexandra Z. Greenbaum   +22 more
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Improved Companion Mass Limits for Sirius A with Thermal Infrared Coronagraphy Using a Vector-apodizing Phase Plate and Time-domain Starlight-subtraction Techniques

The Astronomical Journal, 2023
We use observations with the infrared-optimized Magellan Adaptive Optics (MagAO) system and Clio camera in 3.9 μ m light to place stringent mass constraints on possible undetected companions to Sirius A.
Joseph D. Long, Jared R. Males, Sebastiaan Y. Haffert, Logan Pearce, Mark S. Marley, Katie M. Morzinski, Laird M. Close, Gilles P. P. L. Otten, Frans Snik, Matthew A. Kenworthy, Christoph U. Keller, Philip Hinz, John D. Monnier, Alycia Weinberger, Volker Tolls   +14 more
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Observed Polarized Scattered Light Phase Functions of Planet-forming Disks

The Astrophysical Journal, 2023
Dust particles are the building blocks from which planetary bodies are made. A major goal of studies of planet-forming disks is to constrain the properties of dust particles and aggregates in order to trace their origin, structure, and the associated ...
Christian Ginski, Ryo Tazaki, Carsten Dominik, Tomas Stolker   +3 more
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REACT – A novel flow-independent non-gated non-contrast MR angiography technique using magnetization-prepared 3D non-balanced dual-echo dixon method: Preliminary clinical experience

European Journal of Radiology Open, 2020
Flow-independent relaxation-based non-contrast MR angiography techniques yield good signal-to-noise ratio and high blood-tissue contrast, complementing non-contrast flow-dependent and contrast-enhanced MR angiography techniques in the assessment of ...
Eu Jin Tan, Shuo Zhang, Prasanna Tirukonda, Le Roy Chong   +3 more
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Keck Primary Mirror Closed-loop Segment Control Using a Vector-Zernike Wavefront Sensor

The Astrophysical Journal
We present the first on-sky segmented primary mirror closed-loop piston control using a Zernike wavefront sensor (ZWFS) installed on the Keck II telescope.
Maïssa Salama, Charlotte Guthery, Vincent Chambouleyron, Rebecca Jensen-Clem, J. Kent Wallace, Jacques-Robert Delorme, Mitchell Troy, Tobias Wenger, Daniel Echeverri, Luke Finnerty, Nemanja Jovanovic, Joshua Liberman, Ronald A. López, Dimitri Mawet, Evan C. Morris, Maaike van Kooten, Jason J. Wang, Peter Wizinowich, Yinzi Xin, Jerry Xuan   +19 more
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A Multiband Study of the HR 4796A Disk in the Optical Using MagAO-X

The Astrophysical Journal
We present total intensity images of the debris disk around HR 4796A from observations spanning 2023 to 2025 with the Magellan extreme adaptive optics instrument (MagAO-X).
Jay K. Kueny, Alycia J. Weinberger, Zhe-Yu Daniel Lin, Joseph D. Long, Jared R. Males, Joshua Liberman, Jialin Li, Sebastiaan Haffert, Laird M. Close, Eden McEwen, Maggie Y. Kautz, Olivier Guyon, Logan Pearce, Parker T. Johnson, Katie Twitchell, Alex Hedglen, Avalon Gower, Warren Foster, Jhen Lumbres, Lauren Schatz, Elena Tonucci   +20 more
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JWST/NIRCam Imaging of Young Stellar Objects. IV. Detailed Imaging of the Protoplanetary Disk around TW Hya

The Astronomical Journal
As the nearest protoplanetary disk to Earth ( d = 60.14 pc), TW Hya is one of the most studied protoplanetary disks and a critical benchmark for testing planet formation theories.
Yu-Chia Lin, Jarron Leisenring, Schuyler G. Wolff, Justin Hom, Kellen Lawson, Ewan S. Douglas, George Rieke, Gabriele Cugno, John Debes, Ruobing Dong, Doug Johnstone, Camryn Mullin, Taylor L. Tobin, Kevin R. Wagner, Thomas Greene, Michael R. Meyer, Marcia Rieke   +16 more
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JWST/MIRI Imaging Search for Kinematically Detected Protoplanetary Candidates

The Astronomical Journal
Kinematic perturbations observed with the Atacama Large Millimeter/submillimeter Array in CO line emission provide evidence for a population of embedded giant protoplanets shaping the structure of protoplanetary disks.
Gabriele Cugno, Myriam Benisty, Richard Teague, Anthony Boccaletti, Laurent Pueyo, Marshall Perrin, Mathilde Mâlin, Julien Girard, Valentin Christiaens, Polychronis Patapis, Kellen Lawson, Sean M. Andrews, Jaehan Bae, Marcelo Barraza-Alfaro, Markus J. Bonse, Margot Courtoux, Stefano Facchini, Misato Fukagawa, Greta Guidi, Ravit Helled, Thomas Henning, Jane Huang, Jens Kammerer, Charles J. Law, Giuseppe Lodato, Feng Long, François Ménard, Michael Meyer, Daniel J. Price, Christian Rab, Isabel Rebollido Vazquez, Christophe Pinte, Giovanni Rosotti, Sascha Quanz, Anibal Sierra, Jochen Stadler, Lucas M. Stapper, Tomas Stolker, David J. Wilner, Andrew J. Winter   +39 more
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