Results 21 to 30 of about 241,534 (269)

PERIODIC AND SPORADIC VARIATIONS IN THE SPECTRAL FLUX DENSITY OF THE CAS A SUPERNOVA REMNANT [PDF]

Radio Physics and Radio Astronomy, 2020
Purpose: Based on the long-term study data in all radio spectrum ranges, the nature of deviations of spectral flux density of the Cas A supernova remnant from the tendency of its secular decrease is considered.
A. A. Gorbunov, M. I. Ryabov, A. L. Sukharev, V. V. Bezrukovs   +3 more
doaj   +1 more source

The metal-rich globular clusters of the Milky Way [PDF]

, 1999
We present new (V,V-I)-photometry of the metal-rich globular clusters NGC 5927, 6316, 6342, 6441 and 6760. The clusters show differential reddening up to dE(V-I)=0.32 mag, for which the CMDs are corrected via extinction maps.
Heitsch, F., Richtler, T.
core   +4 more sources

The Host Galaxy Fluxes of Active Galaxy Nuclei Are Generally Overestimated by the Flux Variation Gradient Method

Universe
In terms of the variable nature of normal active galaxy nuclei (AGN) and luminous quasars, a so-called flux variation gradient (FVG) method has been widely utilized to estimate the underlying non-variable host galaxy fluxes.
Minxuan Cai, Zhen Wan, Zhenyi Cai, Lulu Fan, Junxian Wang   +4 more
doaj   +1 more source

Period Change of the Contact Binary AH Tauri [PDF]

Journal of Astronomy and Space Sciences, 2004
New BVRI photometric observations of the contact binary AH Tau were performed with the 61 cm reflector and a 2K CCD camera at the Sobaeksan Optical Astronomy Observatory during seven nights from September to December, 2001. A total of 144 times of minima
Dongjoo Lee, Chung-Uk Lee, Jae Woo Lee, Seung-Lee Kim, Kyu-Dong Oh, Chun-Hwey Kim   +5 more
doaj   +1 more source

No magnetic field variation with pulsation phase in the roAp star gamma Equulei

, 2004
We present an analysis of 210 high-resolution time-resolved spectropolarimetric observations of the roAp star gamma Equ obtained over three nights in August and September 2003.
Kochukhov, O., Piskunov, N., Ryabchikova, T.   +2 more
core   +1 more source

Mass-radius relation for magnetized strange quark stars [PDF]

, 2010
We review the stability of magnetized strange quark matter (MSQM) within the phenomenological MIT bag model, taking into account the variation of the relevant input parameters, namely, the strange quark mass, baryon density, magnetic field and bag ...
A. P. MARTÍNEZ, D. M. PARET, Duncan R., Hansel P., R. G. FELIPE   +4 more
core   +2 more sources

New Astronomical Observatory Design for the Detection and Tracking of Satellite Objects: The Satellite Robotic Observatory (SRO)

Remote Sensing
Robotic Astronomical Observatories (RAOs) have provided very good results in different research projects in astrophysics/astronomy. Their applications in the detection, tracking, and identification of near-Earth objects have contributed to the ...
Francisco Espartero, Javier Cubas, David Nespral, Santiago Pindado   +3 more
doaj   +1 more source

Atmospheric Optical Turbulence Characteristics over the Ocean Relevant to Astronomy and Atmospheric Physics

Applied Sciences, 2021
Due to the space and time constraints of turbulence measurement equipment and the experiment scene, it is difficult to obtain the atmosphere refractive index structure constant over the ocean.
Manman Xu, Shiyong Shao, Ningquan Weng, Liangping Zhou, Qing Liu, Yuefeng Zhao   +5 more
doaj   +1 more source

“Frog-eyes” in astronomy: Monitoring binary radial velocity variations through a pair of narrow-band filters

Science China Physics, Mechanics & Astronomy
Spectroscopic observations are a crucial step in driving major discoveries in the era of time-domain surveys. However, the pace of current spectroscopic surveys is increasingly unable to meet the demands of rapidly advancing large-scale time-domain surveys.
Zheng, Chuanjie, Huang, Yang, Liu, Jifeng, Gu, Hongrui, Wu, Hong, Lu, Youjun, Sun, Yongkang, Han, Henggeng, Wang, Song, Beers, Timothy C., Xiao, Kai, Li, Zhirui, Zhang, Boweng, Mao, Yongna, Li, Zhengyang, Ji, Hangxin   +15 more
openaire   +2 more sources

Constraints on time variation of fine structure constant from WMAP-3yr data

, 2007
This paper presents the constraints on the time variation of the fine structure constant at recombination relative to its present value, Delta_alpha = (alpha_rec-alpha_0) / alpha_0, obtained from the analysis of the WMAP-3yr Cosmic Microwave Background ...
Stefanescu, Petruta
core   +1 more source