Zobrazeno 1 - 10
of 44
pro vyhledávání: '"Radio astrometry"'
Autor:
Valeri V. Makarov, Phil Cigan, David Gordon, Megan C. Johnson, Christopher DiLullo, Sébastien Lambert
Publikováno v:
The Astrophysical Journal Letters, Vol 977, Iss 1, p L14 (2024)
Published analyses of very long baseline interferometry data for the sources included in the third International Celestial Reference Frame catalog have revealed object-specific, excess astrometric variability and quasi-coherent trajectories as functi
Externí odkaz:
https://doaj.org/article/5a804e2b22e64a6babd8625b3925c04e
Publikováno v:
The Astrophysical Journal Letters, Vol 960, Iss 2, p L14 (2024)
Using James Webb Space Telescope near-infrared data of the inner Orion Nebula, Pearson & McCaughrean detected 40 Jupiter-mass binary objects (JuMBOs). These systems are not associated with stars and their components have masses of giant Jupiter-like
Externí odkaz:
https://doaj.org/article/864c468f52f2462f8f0396e858e8650a
Autor:
Shuangjing Xu, Taehyun Jung, Bo Zhang, Ming Hui Xu, Do-Young Byun, Xuan He, Nobuyuki Sakai, Oleg Titov, Fengchun Shu, Hyo-Ryoung Kim, Jungho Cho, Sung-Moon Yoo, Byung-Kyu Choi, Woo Kyoung Lee, Yan Sun, Xiaofeng Mai, Guangli Wang
Publikováno v:
The Astronomical Journal, Vol 168, Iss 5, p 219 (2024)
Extending geodetic and astrometric Very Long Baseline Interferometry (VLBI) observations from traditional centimeter wavebands to millimeter wavebands offers numerous scientific potentials and benefits. However, it was considered quite challenging du
Externí odkaz:
https://doaj.org/article/497d7b789b4848649ae3e39a6ea9864a
Autor:
Leonid Petrov
Publikováno v:
The Astronomical Journal, Vol 168, Iss 2, p 76 (2024)
The very long baseline interferometry technique allows us to determine the positions of thousands of radio sources using the absolute astrometry approach. I have investigated the impacts of a selection of observing frequencies in a range from 2 to 43
Externí odkaz:
https://doaj.org/article/3c3cd5559d2040fa8f91536d3cb7c6b1
Publikováno v:
The Astronomical Journal, Vol 168, Iss 2, p 53 (2024)
Simultaneous very-long-baseline interferometry monitoring observations of H _2 O and SiO masers toward VX Sagittarii were conducted from 2014 February to 2019 January. Thirty epochs of observations revealed that the H _2 O and SiO masers had asymmetr
Externí odkaz:
https://doaj.org/article/845a7dad64c64632911a276bee85fe23
Publikováno v:
The Astrophysical Journal, Vol 967, Iss 2, p 112 (2024)
LP 349−25 is a well-studied close stellar binary system comprised of two late M dwarf stars, where both stars are close to the limit between star and brown dwarf. This system was previously identified as a source of gigahertz radio emission. We obs
Externí odkaz:
https://doaj.org/article/24f15ed79e0a4ccbb44744098e5f3c21
Publikováno v:
The Astrophysical Journal, Vol 965, Iss 1, p 86 (2024)
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. We determined hourly radio
Externí odkaz:
https://doaj.org/article/8ac9f654a7ea4fb0aa3a3c09a638f4cb
Autor:
Ross J. Jennings, James M. Cordes, Shami Chatterjee, Maura A. McLaughlin, Paul B. Demorest, Zaven Arzoumanian, Paul T. Baker, Harsha Blumer, Paul R. Brook, Tyler Cohen, Fronefield Crawford, H. Thankful Cromartie, Megan E. DeCesar, Timothy Dolch, Elizabeth C. Ferrara, Emmanuel Fonseca, Deborah C. Good, Jeffrey S. Hazboun, Megan L. Jones, David L. Kaplan, Michael T. Lam, T. Joseph W. Lazio, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, James W. McKee, Dustin R. Madison, Bradley W. Meyers, Chiara M. F. Mingarelli, David J. Nice, Timothy T. Pennucci, Benetge B. P. Perera, Nihan S. Pol, Scott M. Ransom, Paul S. Ray, Brent J. Shapiro-Albert, Xavier Siemens, Ingrid H. Stairs, Daniel R. Stinebring, Joseph K. Swiggum, Chia Min Tan, Stephen R. Taylor, Sarah J. Vigeland, Caitlin A. Witt
Publikováno v:
The Astrophysical Journal, Vol 964, Iss 2, p 179 (2024)
The millisecond pulsar J1713+0747 underwent a sudden and significant pulse shape change between 2021 April 16 and 17 (MJDs 59320 and 59321). Subsequently, the pulse shape gradually recovered over the course of several months. We report the results of
Externí odkaz:
https://doaj.org/article/3efce57b3b984c16b8ed4afb4abe7a16
Autor:
Alexander E. Thelen, Katherine de Kleer, Maria Camarca, Alex Akins, Mark Gurwell, Bryan Butler, Imke de Pater
Publikováno v:
The Planetary Science Journal, Vol 5, Iss 2, p 56 (2024)
We present best-fit values of porosity—and the corresponding effective thermal inertiae—determined from three different depths in Europa’s near-subsurface (∼1–20 cm). The porosity of the upper ∼20 cm of Europa’s subsurface varies betwee
Externí odkaz:
https://doaj.org/article/41720d6d33fb4c95878d7cebe26d508d
Autor:
Jazmín Ordóñez-Toro, Sergio A. Dzib, Laurent Loinard, Gisela Ortiz-León, Marina A. Kounkel, Josep M. Masqué, S.-N. X. Medina, Phillip A. B. Galli, Trent J. Dupuy, Luis F. Rodríguez, Luis H. Quiroga-Nuñez
Publikováno v:
The Astronomical Journal, Vol 167, Iss 3, p 108 (2024)
We report dynamical mass measurements of the individual stars in the most luminous and massive stellar member of the nearby Ophiuchus star-forming region, the young tight binary system S1. We combine 28 archival data sets with seven recent proprietar
Externí odkaz:
https://doaj.org/article/f218085a0c914e1fb7f3664b1825da6b