CCD Polarimetry of Near-Earth Asteroid 2014 JO25 and Comet 41P/Tuttle–Giacobini–Kresák at the Prime Focus of the 2.6-m Shajn Telescope of the Crimean Astrophysical Observatory     

Rumyantsev  V. V.  Kiselev  N. N.  Ivanova  A. V. 《Solar System Research》2019,53(2):91-97

The results of the first polarimetric measurements of near-Earth asteroid 2014 JO₂₅ and comet 41P/Tuttle-Giacobini-Kresák performed on April 19, 2017, with a CCD sensor at the prime focus (f/3.85) of the 2.6-m Shajn Telescope of the Crimean Astrophysical Observatory in the R filter are reported. The degree of linear polarization of the asteroid is P = 2.69 ± 0.44% at a phase angle of 55.6°, which is typical of an S-type asteroid. Its geometric albedo is ρ_v ≈ 0.2. A digital filter applied to the direct image of the comet reveals a jet and a tail directed toward the Sun (PA = 45.1°) and away from it (PA = 241.2°), respectively, in the coma. The maximum degree of linear polarization in the near-nucleus region of the comet is 18% at a phase angle of 69.8°. The polarization decreases to 16.2–10.7% in coma regions with a radius of 865–4856 km. Various factors affecting the maximum degree of polarization and the polarization-degree distribution over the coma are discussed.

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A Review on Marine N2 Fixation: Mechanism,Evolution of Methodologies,Rates, and Future Concerns     

Bhavya  P. S.  Min  Jun-Oh  Kim  Min-Seob  Jang  Hyo Keun  Kim  Kwanwoo  Kang  Jae Joong  Lee  Jae Hyung  Lee  Dabin  Jo  Naeun  Kim  Myung Joon  Kim  Yejin  Lee  Junbeom  Lee  Chang Hwa  Bae  Hyeonji  Yoo  Hyeju  Park  Sanghoon  Yun  Mi Sun  Lee  Sang Heon 《Ocean Science Journal》2019,54(4):515-528

Ocean Science Journal - Investigations on marine N2 fixation have gained momentum since 1960s with eventual establishments of relevant methodologies to identify species involved and quantify the...  相似文献   

Eurasian Large-Scale Hazes in Summer 2016     

Gorchakov  G. I.  Sitnov  S. A.  Karpov  A. V.  Gorchakova  I. A.  Gushchin  R. A.  Datsenko  O. I. 《Izvestiya Atmospheric and Oceanic Physics》2019,55(3):261-270

Izvestiya, Atmospheric and Oceanic Physics - The technique for constructing the spatial distribution of maximum aerosol optical depth (MAOD) has been used to estimate the optically dense haze...  相似文献   

New Orbit and Estimate of the Mass of the Star 61 Cygni Based on Observations of it in 1819-2019     

Izmailov  I. S.  Shakht  N. A.  Polyakov  E. V.  Gorshanov  D. L.  Pogodin  M. A. 《Astrophysics》2021,64(2):160-171

Astrophysics - This paper is a continuation of our earlier work devoted to determining the orbit and mass of the star 61 Cyg and the changes in the photometric characteristics of its components....  相似文献   

Discovery of the First Interstellar Comet and the Spatial Density of Interstellar Objects in the Solar Neighborhood     

Borisov  G. V.  Shustov  B. M. 《Solar System Research》2021,55(2):124-131

Solar System Research - The discovery of the first interstellar comet 2I/Borisov confirmed the astronomers’ speculation that the passage through the solar system of relatively large objects...  相似文献   

Changes in the Period of Negative Superhumps of Type SU UMa Dwarf Novae. II. NY Her (2017 and 2020)     

Pavlenko  E. P.  Sosnovskii  A. A.  Antonyuk  K. A.  Antonyuk  O. I.  Pit’  N. V.  Kokhirova  G. I.  Rakhmatullaeva  F. J.  Baklanov  A. V. 《Astrophysics》2021,64(3):293-305

Astrophysics - Photometric studies of the type SU UMa dwarf nova NY Her were made during 2017 and 2020 at the Crimean Astrophysical Observatory and at the Sanglokh Observatory over a total of 77...  相似文献   

Sources of variability in springwater chemistry in Fool Creek,a high-elevation catchment of the Rocky Mountains,Colorado, USA     

Charles C. Rhoades  Timothy S. Fegel  Timothy P. Covino  Kathleen A. Dwire  Kelly Elder 《水文研究》2021,35(3):e14089

Springs are the point of origin for most headwater streams and are important regulators of their chemical composition. We analysed solute concentrations of water emerging from 57 springs within the 3 km² Fool Creek catchment at the Fraser Experimental Forest and considered sources of spatial variation among them and their influence on the chemical composition of downstream water. On average, calcium and acid neutralizing capacity (bicarbonate-ANC) comprised 50 and 90% of the cation and anion charge respectively, in both spring and stream water. Variation in inorganic chemical composition among springs reflected distinct groundwater sources and catchment geology. Springs emerging through glacial deposits in the upper portion of the catchment were the most dilute and similar to snowmelt, whereas lower elevation springs were more concentrated in cations and ANC. Water emerging from a handful of springs in a geologically faulted portion of the catchment were more concentrated than all others and had a predominant effect on downstream ion concentrations. Chemical similarity indicated that these springs were linked along surface and subsurface flowpaths. This survey shows that springwater chemistry is influenced at nested spatial scales including broad geologic conditions, elevational and spatial attributes and isolated local features. Our results highlight the role of overlapping factors on solute export from headwater catchments.  相似文献   

METEOR-L Device on the Lunar Orbital Vehicle Luna-26: Space Dust Detector     

Slyuta  E. N.  Vysochkin  V. V.  Ivanov  V. V.  Makovchuk  V. Yu.  Nazarov  A. I.  Pogonin  V. I.  Roskina  E. A.  Safronov  V. V.  Tatsiy  L. P. 《Solar System Research》2021,55(5):437-445

Solar System Research - The ionization-type cosmic dust detector METEOR-L is being developed for the lunar orbiter Luna-26 and is designed to study the distribution of meteoric bodies in space by...  相似文献   

Estimates of Extragalactic Background and Confusion Noise Parameters for the Millimetron Telescope     

Ermash  A. A.  Pilipenko  S. V.  Lukash  V. N. 《Astronomy Letters》2020,46(5):298-311

Astronomy Letters - The sensitivity of future far-infrared telescopes, such as Millimetron, will be limited by the confusion noise produced by distant galaxies. We have constructed a model of the...  相似文献   

Retrieving Sea Wave Spectra Based on High Resolution Satellite Imagery under Different Conditions of Wave Generation     

Bondur  V. G.  Vorobyev  V. E.  Murynin  A. B. 《Izvestiya Atmospheric and Oceanic Physics》2020,56(9):887-897

Izvestiya, Atmospheric and Oceanic Physics - A method for retrieving sea wave spectra from space images of high spatial resolution has been developed for various conditions of wave generation based...  相似文献