Results 31 to 40 of about 4,001,813 (277)
Is Flat Fielding Safe for Precision CCD Astronomy? [PDF]
, 2017 The ambitious goals of precision cosmology with wide-field optical surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope (LSST) demand precision CCD astronomy as their foundation.
M. Baumer, C. Davis, A. Roodman
semanticscholar +1 more source
On Measuring the Variation of High-energy Cutoff in Active Galactic Nuclei [PDF]
Astrophysical Journal, 2018 The variation in the high energy cut-off E_c in active galactic nuclei uniquely probes the corona physics. In this work we show that the ratio of two NuSTAR spectra (in analogy to difference imaging technique widely used in astronomy) is uniquely useful ...
Jixie Zhang, Junxian Wang, Fei-Fan Zhu
semanticscholar +1 more source
Light Curve Analysis of SAO23229 [PDF]
Journal of Astronomy and Space Sciences, 1993 We have made UBV light curves of a newly discovered eclipsing binary, SAO23229 at Sobaeksan Astronomy Observatory. We determined a minimum light time of HJD2448636.1170+/-0.0005 that is 3 minutes later than predicted time, and founda peculiar light ...
Ho-Il Kim +3 more
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A modified method for determining the focal ratio degradation and length properties of optical fibres in astronomy [PDF]
, 2017 Focal ratio degradation (FRD) is a major contributor to throughput and light loss in a fibre spectroscopic telescope system. We combine the guided mode theory in geometric optics and a well-known model, power distribution model (PDM), to predict and ...
Yunxiang Yan +6 more
semanticscholar +1 more source
Roche Model and Absolute Dimensions of the Eclipsing Binary Y Cam with a Pulsating Component [PDF]
Journal of Astronomy and Space Sciences, 2002 We performed CCD photometric observations of the eclipsing binary Y Cam with a pulsating component, for 16 nights from November 2000 to May 2001 using a V filter attached to the 61-cm reflector at Sobaeksan Optical Astronomy Observatory.
J. W. Lee +4 more
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Cepstrum Analysis of Terrestrial Impact Crater Records [PDF]
Journal of Astronomy and Space Sciences, 2008 Study of terrestrial impact craters is important not only in the field of the solar system formation and evolution but also of the Galactic astronomy. The terrestrial impact cratering record recently has been examined, providing short- and intermediate ...
Heon-Young Chang, Cheongho Han
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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 +3 more
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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 +5 more
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Astronomy & AstrophysicsWater vapor is the main source of atmospheric opacity for millimeter and sub-millimeter astronomy. Hence, several studies seek to effectively characterize it for site-testing purposes.
L. Valeria +2 more
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Spatial Variation of the Chemical Properties of Massive Star-forming Clumps [PDF]
Astrophysical Journal Supplement Series, 2019 We selected 90 massive star-forming clumps with strong N2H+(1−0), HCO+(1−0), HCN(1−0), and HNC(1−0) emission from the Millimetre Astronomy Legacy Team 90 GHz survey. We obtained Herschel data for all 90 sources and NRAO VLA Sky Survey data for 51 of them.
Mingyu Li +6 more
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