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Astronomy Reports - A four-year sky survey with the use of the eROSITA telescope on board the Spektr-RG observatory with focusing optics will provide the best coverage in the soft (0.5–2 keV)... 相似文献
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The measurements of pulsar frequency second derivatives have shown that they are 102−106 times larger than expected for standard pulsar spin-down law, and are even negative for about half of pulsars. We explain
these paradoxical results on the basis of the statistical analysis of the rotational parameters ν,
and
of the subset of 295 pulsars taken mostly from the ATNF database. We have found a strong correlation between
and
for both
and
, as well as between ν and
. We interpret these dependencies as evolutionary ones due to
being nearly proportional to the pulsars’ age. The derived statistical relations as well as “anomalous” values of
are well described by assuming the long-time variations of the spin-down rate. The pulsar frequency evolution, therefore,
consists of secular change of ν
ev(t),
and
according to the power law with n≈5, the irregularities, observed within a timespan as a timing noise, and the variations on the timescale larger than that—several
decades.
This work has been supported by the Russian Foundation for Basic Research (grant No 04-02-17555), Russian Academy of Sciences
(program “Evolution of Stars and Galaxies”), and by the Russian Science Support Foundation. The authors would also like to
thank the anonymous referee for valuable comments. 相似文献
3.
G. M. Beskin S. V. Karpov A. V. Biryukov S. F. Bondar E. A. Ivanov E. V. Katkova N. V. Orekhova A. V. Perkov V. V. Sasyuk 《Astrophysical Bulletin》2017,72(1):81-92
We describe the properties of Mini-MegaTORTORA (MMT-9) nine-channel wide-field optical sky monitoring system with subsecond temporal resolution. This instrument can observe sky areas as large as 900 deg2, perform photometry in three filters close to Johnson BV R system and polarimetry of selected objects or areas with 100–300 deg2 sizes. The limiting magnitude of the system is up to V = 11m for 0.1 s temporal resolution, and reaches V = 15m in minute-long exposures. The system is equipped with a powerful computing facility and dedicated software pipeline allowing it to perform automatic detection, real-time classification, and investigation of transient events of different nature located both in the near- Earth space and at extragalactic distances. The objects routinely detected by MMT-9 include faint meteors and artificial Earth satellites.We discuss astronomical tasks that can be solved using MMT-9, and present the results of the first two years of its operation. In particular, we report the parameters of the optical flare detected on June 25, 2016, which accompanied the gamma-ray burst GRB160625B. 相似文献
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A.?A.?ChashkinaEmail author P.?K.?Abolmasov A.?V.?Biryukov N.?I.?Shakura 《Astronomy Reports》2015,59(6):563-572
RXTE observations of the X-ray binary systems SXP 138, GX-304, and γ Cas in 1997–2011 have shown for the first time that these objects (X-ray binaries with Be donors) display X-ray flux variations on timescales of ～1000 days. This timescale is about 10 times longer than their orbital periods, and is comparable to the total time of the observations. The observed variations are apparently not strictly periodic and represent stochastic variability, as is characteristic of such systems in the optical. γ Cas is considered as an example. The series of optical observations of this system available in the AAVSO database covers 78 years, and is much longer than the timescale of the variability studied. Our analysis of this series has shown that γ Cas variability on a timescale of tens of years is predominantly stochastic with a power-law spectrum. 相似文献
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P. K. Shternberg State Astronomical Institute; Crimean Astrophysical Observatory. Translated from Astrofizika, Vol. 31, No. 1, pp. 75–86, July–August, 1989. 相似文献
8.
Ｖ．Ｍ．Ｂｉｒｙｕｋｏｖ 《国土资源》1999,(2)
含紫硅碱钙石、镁钠钙闪石（钠透闪石－石棉）及蓝色软透闪石的碱性交代岩的形成首先是由硅酸和碱（Ｎａ２Ｏ和Ｋ２Ｏ的不同作用）的隋性及ＦｅＯ，ＭｇＯ，ＣａＯ和Ａｌ２Ｏ３的强烈活性决定的。含蓝色软透闪石和镁钠钙闪石（钠透闪石－石棉）的交代岩是岩浆期后溶解演化的中期产物，而含紫硅碱钙石的交代岩却是其晚期的产物。 相似文献
9.
V. V. Emel’yanenko O. P. Popova N. N. Chugai M. A. Shelyakov Yu. V. Pakhomov B. M. Shustov V. V. Shuvalov E. E. Biryukov Yu. S. Rybnov M. Ya. Marov L. V. Rykhlova S. A. Naroenkov A. P. Kartashova V. A. Kharlamov I. A. Trubetskaya 《Solar System Research》2013,47(4):240-254
Various observational data including infrasound, seismic, optical (onboard) monitoring, ground video and photo records, and evidence from witnesses of the Chelyabinsk event on February 15, 2013, have been analyzed. The extensive material gathered has provided a base for investigations of the physical properties of the object, the results of which are discussed. A bolide light curve is constructed, which shows a multiplicity of flashes. Estimations of the energy of the meteoroid explosion, which took place in the atmosphere at an altitude of about 23 km, show evidence of the formation of a high-power shock wave equivalent to 300–500 kilotons of TNT. The object diameter corresponding to this energy falls within the range 16–19 m. The trajectory of the meteor is outlined. It is preliminarily concluded that the Chelyabinsk meteorite was a representative the Apollo asteroid family. 相似文献
10.
A. I. Zakharov A. V. Mironov M. E. Prokhorov A. V. Biryukov O. Yu. Stekol’shchikov M. S. Tuchin 《Astronomy Reports》2013,57(3):195-211
We describe goals and principles for the realization the Lyra-B space experiment onboard the International Space Station, which is currently being prepared at the Sternberg Astronomical Institute. The main goal of the experiment is to carry out a high-accuracy, multicolor all-sky survey of stars down to 16 m –17 m . The detailed structure of the expected observational data, their possible scientific use, and a number of technical problems are discussed. 相似文献