Open Access Published by De Gruyter Open Access

Volume 24 Issue 4

December 2015

Issue of Open Astronomy

Submit manuscript

Contents
Journal Overview

Open Access February 18, 2017

Early Photometric and Spectral Evolution of Nova Cygni 2014 (V2659 Cyg)

M. A. Burlak, V. F. Esipov, G. V. Komissarova

Page range: 345-352

More Download PDF

Abstract

We present optical spectroscopic and UBV ( RI ) C photometric observations of Nova Cygni 2014 (V2659 Cyg) from its rebrightening to the nebular stage. After the first maximum, the nova underwent several irregular flare-like rebrightenings, with amplitudes up to two magnitudes, accompanied with spectral changes. During the bright state, forbidden lines became weaker; the absorption components of Balmer, He I, Fe II, N I, N II, O I lines strengthened, indicating an increase in the density and mass-loss rate in the form of a wind.

Open Access February 18, 2017

Recurrent Symbiotic Nova V407 Cygni: Before and after Outburst in 2010

V. F. Esipov, E. A. Kolotilov, V. I. Shenavrin, T. N. Tarasova, A. M. Tatarnikov, A. A. Tatarnikova

Page range: 353-359

More Download PDF

Abstract

We present the results of our UBV JHKLM photometric and spectroscopic observations of V407 Cyg obtained in 2003–2015. No fast brightness variations of V407 Cyg have been detected since its RS Oph-type outburst in 2010. Now the binary demonstrates a low-excitation emission spectrum with H α weaker than the [N II] 6584 Å line. It is a typical spectrum on the way to the passive state.

Open Access February 18, 2017

A Search for New Open Clusters Hosting Cepheids

E. V. Glushkova, M. V. Zabolotskikh, A. S. Rastorguev, A. V. Grudskaya

Page range: 360-366

More Download PDF

Abstract

We analyze yet-unknown genetic links between open star clusters (OSCs) and galactic Cepheids and report the results of the new search for Cepheids – probable OSC members. A sample of 25% of the stars from a new catalog by Berdnikov (published in Melnik et al. 2015) which lists 674 Cepheids with reliable parameters was investigated. Based on photometric and kinematic data, we selected 17 Cepheids that are likely to be related to star clusters, four of which being new OSCs discovered by us.

Open Access February 18, 2017

Statistical Analysis of a Comprehensive List of Visual Binaries

D. Kovaleva, O. Malkov, L. Yungelson, D. Chulkov, G. M. Yikdem

Page range: 367-378

More Download PDF

Abstract

Visual binary stars are the most abundant class of observed binaries. The most comprehensive list of data on visual binaries compiled recently by cross-matching the largest catalogues of visual binaries allowed a statistical investigation of observational parameters of these systems. The dataset was cleaned by correcting uncertainties and misclassifications, and supplemented with available parallax data. The refined dataset is free from technical biases and contains 3676 presumably physical visual pairs of luminosity class V with known angular separations, magnitudes of the components, spectral types, and parallaxes. We also compiled a restricted sample of 998 pairs free from observational biases due to the probability of binary discovery. Certain distributions of observational and physical parameters of stars of our dataset are discussed.

Open Access February 18, 2017

A Study of Double- and Multi-mode RR Lyrae Variables

A. V. Khruslov

Page range: 379-386

More Download PDF

Abstract

We present the results of our new study of known RR Lyrae variable stars. All observations available for these stars in the Catalina Surveys were analyzed, and double-mode variations were identified. We studied the Petersen diagram and the period distribution for the double-mode RR Lyrae variables in the Galactic field, pulsating in the first-overtone and fundamental modes. The double-peaked character of the period distribution was detected for Galactic RR(B) stars, corresponding to Oosterhoff’s classes of globular clusters, which indicates that the age and evolution stage of RR(B) stars in the field and RR Lyrae variables in globular clusters are probably the same. Besides, we discovered five RRC stars with two simultaneously excited non-radial pulsations (equidistant triplets).

Open Access February 18, 2017

On the Possibility of Determining the Distance to the Galactic Center from the Geometry of Spiral Arm Segments

I. I. Nikiforov, A. V. Veselova

Page range: 387-394

More Download PDF

Abstract

A new approach to determining the solar galactocentric distance, R 0 , from the geometry of spiral-arm segments is proposed. Geometric aspects of the problem are analyzed and a simplified three-point method for estimating R 0 from objects in a spiral segment is developed in order to test the proposed approach. An estimate of R 0 = 8.44 ± 0.45 kpc is obtained by applying the method to masers with measured trigonometric parallaxes, and statistical properties of the R 0 estimation from spiral segments are analyzed.

Open Access February 18, 2017

Binary Star Database: Binaries Discovered in Non-Optical Bands

Oleg Yu. Malkov, Solomon B. Tessema, Alexei Yu. Kniazev

Page range: 395-402

More Download PDF

Abstract

The Binary star Database (BDB) is the world’s principal database of binary and multiple systems of all observational types. In particular, it should contain data on binaries discovered in non-optical bands, X-ray binaries (XRBs) and radio pulsars in binaries. The goal of the present study was to compile complete lists of such objects. Due to the lack of a unified identification system for XRBs, we had to select them from five principal catalogues of X-ray sources. After cross-identification and positional cross-matching, a general catalogue of 373 XRBs was constructed for the first time. It contains coordinates, indication of photometric and spectroscopic binarity, and extensive cross-identification. In the preparation of the catalogue, a number of XRB classification disagreements were resolved, some catalogued identifiers and coordinates were corrected, and duplicated entries in the original catalogues were found. We have also compiled a general list of 239 radio pulsars in binary systems. The list is supplied with indication of photometric, spectroscopic or X-ray binarity, and with cross-identification data.

Open Access February 18, 2017

Potential of a Spheroid with Generalized Exponential Density Distribution

B. P. Kondratyev, E. N. Kireeva

Page range: 403-407

More Download PDF

Abstract

The internal potential of an inhomogeneous layered spheroid with a small ellipticity and general exponential density distribution is derived in an analytical form. The results are presented in the form of standard Gauss hypergeometric function and validated numerically. The computing time when using this formula is noticeably smaller than the time required by numerical integration.

Open Access February 18, 2017

Equilibrium Figures inside the Dark-Matter Ring and the Shapes of Elliptical Galaxies

B. P. Kondratyev, N. G. Trubitsyna, E. N. Kireeva

Page range: 408-420

More Download PDF

Abstract

We solve the general problem of the theory of equilibrium figures and analyze two classes of liquid rotating gravitating figures residing inside a gravitating ring or torus. These figures form families of sequences of generalized oblate spheroids and triaxial ellipsoids, which at the lower limit of the tidal parameter α = 0 have the form of the Maclaurin spheroids and the Jacobi ellipsoids. In intermediate cases 0 < α ≤ α max each new sequence of axisymmetric equilibrium figures has two non-rotating boundary spheroids. At the upper limit α max /( πGρ ) = 0.1867 the sequence degenerates into a single non-rotating spheroid with the eccentricity e cr ≈ 0.96 corresponding to the flattening limit of elliptical galaxies (E7). We also perform a detailed study of the sequences of generalized triaxial ellipsoids and find bifurcation points of triaxial ellipsoids in the sequences of generalized spheroids. We use this method to explain the shapes of E-galaxies. According to observations, very slowly rotating oblate E-type galaxies are known that have the shapes, which, because of instability, cannot be supported by velocity dispersion anisotropy exclusively. The hypothesis of a massive dark-matter outer ring requires no extreme anisotropy of pressure; it not only explains the shape of these elliptical galaxies, but also sheds new light on the riddle of the ellipticity limit (E7) of elliptical galaxies.

Open Access February 18, 2017

Details of the Spatial Structure and Kinematics of the Castor and Ursa Major Streams

S. V. Vereshchagin, N. V. Chupina

Page range: 421-425

More Download PDF

Abstract

A list of the Castor stream members is compiled based on the data from various authors. The membership probabilities for some stars are revised based on the individual apex, multiplicity, observational errors, and peculiarity. The apex of the Castor moving group is determined using the apex diagram method. The parameters of the Castor and Ursa Major streams are compared and the positions of the two streams on the apex diagram are found to differ by 225°, implying that the two groups move in almost opposite directions. Stars of both moving groups are intermixed in space, the Castor stream occupies a smaller volume than the UMa stream and is located inside it. Our results can be useful for understanding the morphology of the Galactic disk in the Sun’s vicinity.

Open Access February 18, 2017

Current Star Formation in the Outer Rings among Early-type Disk Galaxies

I. P. Kostiuk, O. K. Sil’chenko

Page range: 426-430

More Download PDF

Abstract

We use ARRAKIS, the atlas of stellar rings in galaxies (Comerón et al. 2014), based on data of the S4G survey, to compile a list of early-type, S0-Sb, disk galaxies with outer stellar ring-like features (‘pure’ rings, R, or pseudorings, R′). We searched for current star formation signatures within these features through the NUV-maps of the galaxies provided by the ultraviolet space telescope GALEX. We found that current star formation, with the mean age of the young stellar population of less than 200 Myr, is present in about a half of all ‘pure’ rings; and within the pseudorings it is observed almost in all cases.

Open Access February 18, 2017

Simulation of the Motion of Stars Escaping from the Galactic Center

K. S. Shirokova

Page range: 431-434

More Download PDF

Abstract

Motions of stars escaping from the Galactic center are simulated. It is shown that the Galactic bar reduces the initial velocity needed to escape from the Galaxy.

Open Access February 18, 2017

Minor Planet Databases

L. Rykhlova, E. Bakanas

Page range: 435-445

More Download PDF

Abstract

We cast a retrospective look at the mankind’s acquaintance with minor bodies of the Solar System, at the explosive growth in their discoveries resulting from the technological progress, and at gradual understanding of the danger to our very existence that some of them might actually pose. Then, we review current effort, of the astronomical community in general and of its Russian part in particular, to integrate our rapidly expanding knowledge of the potential Earth impactors and to make it readily available online.

Open Access February 18, 2017

Astronomical Data Resources for Binary and Multiple Stars

D. Kovaleva

Page range: 446-452

More Download PDF

Abstract

Binary stars form a significant part of stellar population. They are registered and observed by a number of methods. This is the reason for variety of present-day resources of astronomical data dealing with binaries and multiples. The review of observational types of binary stars and of basic data resources for them is presented. The properties of stars within these types and possible relationships between them are discussed. The Binary star DataBase, BDB (http://bdb.inasan.ru), is presented as the resource joining data for all observational types of binaries. The problem of correct cross-identification of objects within binary and multiple stars is being solved in the frame of the Identification List of Binaries (ILB).

Open Access February 18, 2017

Archives of Astronomical Spectral Observations and Atomic/Molecular Databases for their Analysis

T. Ryabchikova, Yu. Pakhomov

Page range: 453-461

More Download PDF

Abstract

We present a review of open-source data for stellar spectroscopy investigations. It includes lists of the main archives of medium-to-high resolution spectroscopic observations, with brief characteristics of the archive data (spectral range, resolving power, flux units). We also review atomic and molecular databases that contain parameters of spectral lines, cross-sections and reaction rates needed for a detailed analysis of high resolution, high signal-to-noise ratio stellar spectra.

Open Access February 18, 2017

Databases of Publications and Observations as a Part of the Crimean Astronomical Virtual Observatory

A. Shlyapnikov, N. Bondar’, M. Gorbunov

Page range: 462-468

More Download PDF

Abstract

We describe the main principles of formation of databases (DBs) with information about astronomical objects and their physical characteristics derived from observations obtained at the Crimean Astrophysical Observatory (CrAO) and published in the “Izvestiya of the CrAO” and elsewhere. Emphasis is placed on the DBs missing from the most complete global library of catalogs and data tables, VizieR (supported by the Center of Astronomical Data, Strasbourg). We specially consider the problem of forming a digital archive of observational data obtained at the CrAO as an interactive DB related to database objects and publications. We present examples of all our DBs as elements integrated into the Crimean Astronomical Virtual Observatory. We illustrate the work with the CrAO DBs using tools of the International Virtual Observatory: Aladin, VOPlot, VOSpec, in conjunction with the VizieR and Simbad DBs.

About this journal

Past events:

The Hubble Tension: Current Research and New Perspectives
Modern Stellar Astronomy 2022
New Technology for Space Environment Detection Based on Beidou Constellation
New Progress in Astrodynamics Applications
Modern Stellar Astronomy 2021
The Global Space Exploration Conference (GLEX) 2021
Astromineralogy and cosmochemistry of the Kaba meteorite: A massage from the early Solar System

Good news! For a limited time only, we have a promotion for a publication fee of €500 for each high-quality paper! Feel welcome to submit your papers with a -50% discount!

Open Astronomy is a peer-reviewed, fully open access online journal, that publishes research, reviews and news spanning all aspects of astronomy and astrophysics.

The journal disseminates research in both observational and theoretical astronomy, astrophysics, solar physics, cosmology, galactic and extragalactic astronomy, high energy particles physics, planetary science, space science and astronomy-related astrobiology, presenting as well the surveys dedicated to astronomical history and education.

Open Astronomy (formerly Baltic Astronomy) was founded by the Institute of Theoretical Physics and Astronomy (Lithuania) in 1992 and acquired by De Gruyter in 2016.

Why publish in Open Astronomy?

all articles are available to read, download and share for free
tracking available during the entire publication process - from submission to the publishing of manuscript via Editorial Manager System,
no space constraints, high-resolution images embedded in texts,
authors retain copyright of articles published in Open Astronomy, there is no embargo period on self-archiving,
visibility and discoverability: promotion of single articles to scientific and general press

Open Astronomy does not have submission charges. Open Astronomy has implemented Article Publication Charges (APCs) since 2018. For more details on Article Processing Charges please go to Supplementary Information section below and view "Article Processing Charges" document (in PDF).

The journal is archived in Portico to ensure long-term monitoring, archiving, and management of the electronic publications stored on its servers.

Detailed information on Editorial Policy, Publication Ethics, Instructions for Authors etc. can be found below and in the Supplementary Information section.

Journal Partner:

12th Serbian Conference on Spectral Line Shapes in Astrophysics (Vrdnik, Serbia, June 3-7, 2019)
Guest Editors: Luka C. Popovic, Dragana Ilic, and Andjelka Kovacevic
The deadline for submitting papers is by July 31st, 2019.