Results 31 to 40 of about 6,767,247 (161)
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
doaj
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
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
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
Variational views for self-supervised learning in radio astronomy
RAS Techniques and InstrumentsABSTRACT Modern astronomical surveys are producing progressively larger and more complex data sets, making traditional supervised approaches that rely on extensive labelled catalogues increasingly difficult. Consequently, pre-training using self-supervised learning (SSL), which offers a scalable route by extracting structure directly ...
Johnny Joseph Alphonse, Anna M M Scaife
openaire +2 more sources
Report of combined meeting of Commissions 8 (Meridian Astronomy), 19 (Variation Of Latitude) and 31 (Time), August 21. 9.30 a.m [PDF]
Transactions of the International Astronomical Union, 1950 The President outlined the history of the Ross photographic zenith tube, saying that it was originally designed for measurement of the variation of latitude by Dr Ross, and later adapted to the determination of time by Dr Littel. The success of the instrument and its possible application to various problems in positional astronomy made it of interest ...
openaire +1 more source
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. Valéria +2 more
semanticscholar +1 more source
Astronomy & Astrophysics (CAUCASUS)-VOLUME 2
, 2020 The second volume of the international scientific journal Astronomy & Astrophysics (Caucasus) contains the scientific works delivered as scientific reports by their authors at International Scientific Conference Modern Problems of Astrophysics – II ...
(CAUCASUS), Astronomy & Astrophysics
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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
doaj +1 more source