Results 91 to 100 of about 11,731 (215)

VLA+PT Astrometry of 46 Radio Stars

, 2006
We have used the Very Large Array (VLA), linked with the Pie Town Very Long Baseline Array antenna, to determine astrometric positions of 46 radio stars in the International Celestial Reference Frame (ICRF). Positions were obtained in the ICRF directly through phase referencing of the stars to nearby ICRF quasars whose positions are accurate at the 0 ...
Boboltz, D. A., Fey, A. L., Puatua, W. K., Zacharias, N., Claussen, M. J., Johnston, K. J., Gaume, R. A.   +6 more
openaire   +2 more sources

Radio-loudness Statistics of Quasars from Quaia-VLASS

The Astrophysical Journal Supplement Series
Quasars are objects of high interest in extragalactic astrophysics, cosmology, and astrometry. One of their useful qualities is their potential radio-loudness.
Nestor Arsenov, Sándor Frey, András Kovács, Lyuba Slavcheva-Mihova   +3 more
doaj   +1 more source

Radio Follow-up Observations of SN 2023ixf by Japanese and Korean Very Long Baseline Interferometers

The Astrophysical Journal
We report on radio follow-up observations of the nearby Type II supernova SN 2023ixf, spanning from 1.7 to 269.9 days after the explosion, conducted using three very long baseline interferometers (VLBIs), which are the Japanese VLBI Network, the VLBI ...
Yuhei Iwata, Masanori Akimoto, Tomoki Matsuoka, Keiichi Maeda, Yoshinori Yonekura, Nozomu Tominaga, Takashi J. Moriya, Kenta Fujisawa, Kotaro Niinuma, Sung-Chul Yoon, Jae-Joon Lee, Taehyun Jung, Do-Young Byun   +12 more
doaj   +1 more source

VLBI Astrometry of the Stellar Image of U Herculis, Amplified by the 1667 OH Maser [PDF]

, 2000
The OH 1667 MHz maser in the circumstellar shell around the Mira variable U Herculis has been observed with the NRAO Very Long Baseline Array (VLBA) at 6 epochs, spread over 4 years.
Baudry, A., Beasley, A. J., Diamond, P. J., van Langevelde, H. J., Vlemmings, W.   +4 more
core   +2 more sources

Astrometry of H$_{2}$O Masers in Nearby Star-Forming Regions with VERA --- IV. L1448C

, 2010
We have carried out multi-epoch VLBI observations with VERA (VLBI Exploration of Radio Astrometry) of the 22~GHz H$_{2}$O masers associated with a Class 0 protostar L1448C in the Perseus molecular cloud.
Hirota, Tomoya, Honma, Mareki, Imai, Hiroshi, Kawaguchi, Noriyuki, Kobayashi, Hideyuki, Sunada, Kazuyoshi, Ueno, YuJi   +6 more
core   +1 more source

Lunar radio astrometry [PDF]

The accuracy of Earth-based radio astronomy is limited in a fundamental way by the variable delay of the troposphere and by the centimeter-scale motions of a dynamic Earth.
Linfield, Roger
core   +1 more source

Astrometry of Galactic Star Forming Region Sharpless 269 with VERA : Parallax Measurements and Constraint on Outer Rotation Curve

, 2007
We have performed high-precision astrometry of H2O maser sources in Galactic star forming region Sharpless 269 (S269) with VERA. We have successfully detected a trigonometric parallax of 189+/-8 micro-arcsec, corresponding to the source distance of 5.28 +
Bushimata, Takeshi, Choi, Yoon Kyung, Hirota, Tomoya, Honma, Mareki, Imai, Hiroshi, Iwadate, Kenzaburo, Jike, Takaaki, Kameya, Osamu, Kamohara, Ryuichi, Kan-ya, Yukitoshi, Kawaguchi, Noriyuki, Kijima, Masachika, Kobayashi, Hideyuki, Kuji, Seisuke, Kurayama, Tomoharu, Manabe, Seiji, Miyaji, Takeshi, Nagayama, Takumi, Nakagawa, Akiharu, Oh, Chung Sik, Omodaka, Toshihiro, Oyama, Tomoaki, Sakai, Satoshi, Sasao, Tetsuo, Sato, Katsuhisa, Shibata, Katsunori M., Shintani, Motonobu, Suda, Hiroshi, Tamura, Yoshiaki, Tsushima, Miyuki, Yamashita, Kazuyoshi   +30 more
core   +2 more sources

A Geodetic and Astrometric VLBI Experiment at 22/43/88/132 GHz

The Astronomical Journal
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 due to
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   +16 more
doaj   +1 more source

Optical-uv spectrum and proper motion of the middle-aged pulsar b1055-52

, 2010
PSRB1055-52 is a middle-aged (~535 kyr) radio, X-ray, and gamma-ray pulsar showing X-ray thermal emission from the neutron star (NS) surface. A candidate optical counterpart to PSRB1055-52 was proposed by Mignani and coworkers based on Hubble Space ...
Abdo, Apellánez, Becker, Bignami, Brinkmann, Brisken, Caraveo, Caraveo, Cordes, De Luca, de Zeeuw, G. G. Pavlov, Greiveldinger, Guillemot, Høg, Kaplan, Kargaltsev, Kargaltsev, Lasker, Lattanzi, Manchester, Manchester, Mignani, Mignani, Monet, Newton, Nota, O. Kargaltsev, Pavlov, Pavlov, Pavlov, Pavlov, Perryman, Predehl, R. P. Mignani, Roeser, Seaton, Shibanov, Skrutskie, Thompson, Vande Putte, Vaughan, Wang, Zacharias, Zacharias, Zavlin   +45 more
core   +1 more source

Multi-wavelength differential astrometry of the S5 polar cap sample

, 2004
We report on the status of our S5 polar cap astrometry program. Since 1997 we have observed all the 13 radio sources of the complete S5 polar cap sample at the wavelengths of 3.6 cm, 2 cm and 7 mm. Images of the radio sources at 3.6 and 2 cm have already
Guirado, J. C., Marcaide, J. M., Marti-Vidal, I., Perez-Torres, M. A., Ros, E.   +4 more
core