Analysis of the nonstationarity of the atmosphere of α Cyg. III. Variability of the Hα-line profile

The temporal variations of the radial velocity and profile of the Hα line in the spectrum of α Cyg are analyzed based on 240 CCD spectra taken with the coude spectrograph attached to the 2-m telescope of Shamaha Astrophysical Observatory of the National Academy of Sciences of Azerbaijan in 1998–2000. The results obtained are inconsistent with the conclusion made by the Heidelberg group concerning the behavior of the variability of the Hα-line profile [1]. The observed pattern of radial-velocity variations is due to nonradial pulsations and differs for the blue and red halves of the absorption profile. The pulsation parameters differ for different levels of residual intensity for both halves of the absorption profile. The amplitude and period increase from the core toward the wing of the line for the red half of the absorption profile, and, on the contrary, decrease toward the line wing for the blue half of the profile. Absorption features are observed on the blue half of the absorption profile. Their emergence and disappearance, as well as minor migrations are indicative of the clumpy structure of the stellar envelope. The similarity of the variability behavior of the absorption and emission profiles indicates that the latter too owe their variability to nonradial pulsations. Thus the variability of the stellar wind in its formation regions is partly due to the nonradial pulsations of the underlying layers of the atmosphere. On the whole, the variability of the position and photometric parameters of the absorption and emission components of the profile is indicative of the nonstationary nature and asymmetric shape of the stellar wind.     

Rhombic Cell Analysis. Ⅱ. Application to the IRAS／PSCz Catalogue

Rhombic cell analysis as outlined in the first paper of the present seriesis applied to samples of varying depths and liming luminosities of the IRAS/PSCzCatalogue. Numerical indices are introduced to summarize essential information.Because of the discrete nature of the analysis and of the space distribution of galax-ies, the indices for a given sample must be regarded as each having an irreduciblescatter. Despite the scatter, the mean indices show remarkable variations acrossthe samples. The underlying factor for the variations is shown to be the limitingluminosity rather than the sampling depth. As samples of more and more luminousgalaxies are considered over a range of some 2.5 magnitudes (a factor of some 75in space density), the morphology of the filled and empty regions defined by thegalaxies degrades steadily towards insignificance, and the degrading is faster for thefilled than the empty region.     

Solar Radio Bursts in the Period Oct. 22-Nov. 4, 2003

A series of solar radio bursts were observed in AR NOAA 10486 withthe Solar Broadband (1.1--7.6 GHz) Radio Spectrometers (SBRS of China). Here weanalyze four significant events associated with CME events and strong X-ray flaresthat occurred on 2003 October 22, 26, 27, 29. The Oct. 26 event is a long durationevent (LDE) with drift pulsation structure (DPS), narrowband dm-burst (DCIM),and more than seven types of Fine Structures (FSs); its time of the maximum flux(07:30 UT) is about half an hour later than the X-flare (06:54 UT).     

Comments on ‘the equation of polarization transfer in an inhomogeneous magnetized plasma. I. Formalism’ by F.T. Cheng and P.C.W. Fung

In their discussion of the transfer of polarized radiation in a weakly anisotropic, weakly inhomogeneous plasma, Cheng and Fung (1977) have included terms which describe the effects of mode coupling and of the variation of the characteristic polarizations. The latter effect is nonphysical, and only the mode-coupling term should be retained. As the problem was formulated by Cheng and Fung, the two terms would cancel exactly; consequently, when corrected, the work of Cheng and Fung leads to a simple and useful method of including the effects of mode coupling in the weak anisotropy limit.On leave from Department of Theoretical Physics, Faculty of Science, Australian National University.     

Variable Stars in the 50BiN Open Cluster Survey. Ⅲ. NGC 884

Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky Way.Variable stars in open clusters provide a unique way to accurately probe the internal structure,temporal and dynamical evolutionary stages of individual stars and the host cluster.The most powerful tool for such studies is time-domain photometric observations.This paper follows the route of our previous work,concentrating on a photometric search for variable stars in...     

Rhombic Cell Analysis - A New Way of Probing the Large- Scale Structure of the Universe. I.General Considerations

A new way of probing the harge-scale structure of the universe is proposed.Space is partitioned into cells the shape of rhombic dodecahedron.The cells are labelled “filled“ or “empty“ according as they contain galaxies or not ,the cell size is so chosen as to have narly equal numbers of filled and empty cells for the given galaxy sample.Two observables on each cell are definable:the number of ist like neighbors,n1,and a two-suffixed topological type τ,the suffixes being the numbers of its like and unlike neighbor-groups.The frequency distributions of n1 and τ in the observed set of filled(empty)cells are then considered as indicators of the morphology of the set,The method is applied to the CfA catalogue of galaxies as an illustration.Despite its limited size,the data offers evidence 1) that the empty cells are more stongly clustered than the filled cells,and 2) theat the filled cells,but not the empty cells,have a tendency to occur in sheets,Further directions of development both in theory and application are indicated.     

Asteroids,comets, meteoric matter: Proceedings of the IAU Colloquium No. 22, held at the University of Nice,France, April 4–6, 1972. Edited by C. Cristescu,W. J. Klepczynski,and B. Milet. Acad. Rep. Soc. Romania,Bucharest, 1974. 333 pp., 27 L

A model is proposed for single close encounters between two small masses, m₁and m₂, which orbit a much larger mass, M. The main new feature of the model is the assumption of conic motion of the center of mass of m₁and m₂ in the gravitational field of M. Comparisons of the model with the three-body equations of motion indicate that the model is a useful approximation for m₁, m₂ ? 10^?5M. The model is therefore applicable for encounters between bodies of the order of an earth mass or smaller in the presence of the sun. Comparisons are also made of outcomes obtained by the model with outcomes of numerical integration for a large variety of close encounters. The above comparisons reveal that for many purposes the model is an adequate approximation for those encounters with ? ≥ 4, where ? is the eccentricity of the hyperbolic orbit of m₁about m₂.     

Searches for HH objects in star formation regions. VII. Herbig-Haro objects in the region of the nebula GM 2–41

Five new Herbig-Haro objects (HH 1036–1040) have been discovered in the neighborhood of the nebula GM 2–41 in a region with an area of 14′ × 14′, at the center of the HII region DR 15 located in the southern periphery of the Cyg OB2 association. Four of them have a complex structure typical of HH flows. Hydrogen molecular emission is detected in the object HH 1036 using archived images from the Spitzer telescope. Two new infrared nebulae illuminated by very red young stellar objects are also found.     

Identification of peculiar A-stars. I. Analysis of the equivalent width of the 2786–2810 Å spectral band and the MgII 4481 Å line for 137 A-stars

The dependence of the equivalent widths of the 2786–2810 Å spectral band and the MgII 4481 Å line on the basic parameters (T_eff, logg and [M/H]) for 137 bright A-stars shows that 60 of them are candidate peculiar stars. Given the similar behavior of W(2800) and W(4481), it can be assumed that 34 of the stars are chemically peculiar stars. The anomalous values of W(2800), W(4481), and [M/H] vary over wide limits for the rest of the stars, possibly because they are binary. Translated from Astrofizika, Vol. 51, No. 4, pp. 577–593 (November 2008).     

Martian occultation of ϵ Gem as observed from the C. E. Kenneth Mees observatory

Ground-based observations of the occultation of ? Gem by Mars on April 8, 1976 have been reduced in the manner of French et al. [Icarus 33, 186–202 (1978)] to yield the scale height and temperature profiles of the Martian atmosphere for number densities between 10¹³ and 10¹⁵ cm^?3. The deduced variations in temperature are remarkably similar to those obtained by Elliot et al. [Astrophys. J.217, 661–679 (1977)] and to the in situ measurements from the Viking landers.     

Comment on “Evidence for a very high carbon/iridium ratio in the Tunguska impactor” by K. L. Rasmussen,H. J. F. Olsen,R. Gwozdz and E. M. Kolesnikov

Abstract— We discuss possible evidence for a dilution of ¹⁴C caused by the Tunguska impact event, proposed by Rasmussen et al. (1999). The results presented in that paper and other available information do not support this hypothesis.     

Exploring the Moon's surface for remnants of the lunar mantle 1. Dunite xenoliths in mare basalts. A crustal or mantle origin?

Remotely sensed observations from recent missions (e.g., GRAIL, Kaguya, Chandrayaan‐1) have been interpreted as indicating that the deep crust and upper mantle are close to or at the lunar surface in many large impact basins (e.g., Crisium, Apollo, Moscoviense). If this is correct, the capability of either impact or volcanic processes to transport mantle lithologies to the lunar surface should be enhanced in these regions. Somewhat problematic to these observations and interpretations is that examples of mantle lithologies in the lunar sample collection (Apollo Program, Luna Program, lunar meteorites) are at best ambiguous. Dunite xenoliths in high‐Ti mare basalt 74275 are one of these ambiguous examples. In this high‐Ti mare basalt, olivine occurs in three generations: olivine associated with dunite xenoliths, olivine megacrysts, and olivine microphenocrysts. The dunite xenoliths are anhedral in shape and are generally greater than 800 μm in diameter. The interior of the xenoliths are fairly homogeneous with regard to many divalent cations. For example, the Mg# (Mg/Mg + Fe × 100) ranges from 82 to 83 in their interiors and decreases from 82 to 68 over the 10–30 μm wide outer rim. Titanium and phosphorus X‐ray maps of the xenolith illustrate that these slow diffusing elements preserve primary cumulate zoning textures. These textures indicate that the xenoliths consist of many individual olivine grains approximately 150–200 μm in diameter with low Ti, Al, and P cores. These highly incompatible elements are enriched in the outer Fe‐rich rims of the xenoliths and slightly enriched in the rims of the individual olivine grains. Highly compatible elements in olivine such as Ni exhibit a decrease in the rim surrounding the xenolith, an increase in the incompatible element depleted cores of the individual olivine grains, and a slight decrease in the “interior rims” of the individual olivine grains. Inferred melt composition, liquid lines of descent, and zoning profiles enable the reconstruction of the petrogenesis of the dunite xenoliths. Preservation of primary magmatic zoning (Ti, P, Al) and lack of textures similar to high‐pressure mineral assemblages exhibited by the Mg‐suite (Shearer et al. 2015) indicate that these xenoliths do not represent deep crustal or shallow mantle lithologies. Further, they are chemically and mineralogically distinct from Mg‐suite dunites identified from the Apollo 17 site. More likely, they represent olivine cumulates that crystallized from a low‐Ti mare basalt at intermediate to shallow crustal levels. The parent basalt to the dunite xenolith lithology was more primitive than low‐Ti basalts thus far returned from the Moon. Furthermore, this parental magma and its more evolved daughter magmas are not represented in the basalt sample suite returned from the Taurus‐Littrow Valley by the Apollo 17 mission. The dunite xenolith records several episodes of crystallization and re‐equilibration. During the last episode of re‐equilibration, the dunite cumulate was sampled by the 74275 high‐Ti basalt and transported over a period of 30–70 days to the lunar surface.     

Speckle interferometry of magnetic stars with the BTA. II. Results of 2010–2012 observations

We present the results of speckle interferometric observations of 156 stars possessing global magnetic fields, carried out with the 6-m BTA telescope of the Special Astrophysical Observatory. Virtually all stars were observed between 2010 and 2012. Thirty-four stars were resolved into individual components (31 double and 3 triple), of which 14 binary systems (BD+41○43, HD2887, HD30466, HD36540, HD36955, HD37479, HD61045, HD89069, HD144334, HD164258, HD349321, HD343872, HD184471, HD196691) and 2 triple systems (HD37140, HD338226) were for the first time resolved by the astrometric method.     

Comments on ‘the angle-dependent redistribution functionsR III andR IV’ by S. J. McKenna

It is shown that the complicated form of the line absorption probability function for scattering in subordinate lines, derived by McKenna (1984), is an artifact of adopting a mathematically inconvenient expression for the corresponding redistribution function. It is demonstrated that the absorption probability must be given by the Voigt function.     

Investigation of galaxies of the second byurakan sky survey. II. Spectroscopic observations in the 08h00m, +59° field

The results of spectroscopic observations of 25 objects of the Second Byurakan Spectroscopic Sky Survey in a field with central coordinates a = 08^h00^m, δ = +59° are given. The spectra were obtained on the 2.6- m telescope of the Byurakan Astrophysical Observatory, National Academy of Sciences of the Republic of Armenia, and the 6- m telescope of the Special Astrophysical Observatory, Russian Academy of Sciences, in 1997– 1998 with a spectral resolution of from 5 to 15Å. The redshifts and absolute stellar magnitudes of all the galaxies were determined and they were classified. A histogram of the redshift distribution of the complete sample of galaxies in this field of the survey is given.     

The Multi-Wavelength Quasar Survey IV. Quasars in the Leo Cluster

We aim to providea quasar sample that is more complete than any previous surveys by using a combined selection technique to reduce the selection effects. Here we present the observational results for the X-ray candidates in the field of the Leo Cluster. We found 33 X-ray AGNs in this field of which 10 are new discoveries. The X-ray data and optical spectra of these AGNs are given. We also study the near-IR properties of the X-ray-selected AGNs by using the data from 2MASS. Most of the AGNs in our sample span the color range 0.0 < B-J < 2.5, 1.0 < J-Ks < 2.0 and 0.5 < H-Ks < 1.2.     

The Multi-Wavelength Quasar Survey Ⅳ. Quasars in the Leo Cluster

We aim to provide a quasar sample that is more complete than any previous surveys by using a combined selection technique to reduce the selection effects. Here we present the observational results for the X-ray candidates in the field of the Leo Cluster. We found 33 X-ray AGNs in this field of which 10 are new discoveries. The X-ray data and optical spectra of these AGNs are given. We also study the near-IR properties of the X-ray-selected AGNs by using the data from 2MASS. Most of the AGNs in our sample span the color range 0.0〈B-J〈2.5,1.0〈 J-Ks 〈2.0 and 0.5〈H-Ks〈1.2.