bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiwavelength observations of eclipsing polars
Authors: Schwope A. , Hambaryan V. , Staude A. , Schwarz R. , Kanbach G. , Steinle H. , Schrey F. , Marsh T. , Dhillon V. , Osborne J. , Wheatley P. , Potter S. 
Published: July 2016

AbstractMultiwavelength observations of polars are essential for developing the big picture of these systems, particularly to gain understanding of the relevant accretion-induced heating and cooling processes. Eclipsing polars are prime targets for such studies since different radiation processes can be disentangled by observations with high-time resolution. We present a preliminary combined analysis of space-based observations (XMM-Newton, ROSAT, HST) with ground-based high-speed photometry (MCCP, OPTIMA, ULTRACAM) of DP Leo, HU Aqr and UZ For. We determine the location and extent of different emission components and find secular and short-term changes in the accretion geometries. We find displaced optical and X-ray emission regions in DP Leo and HU Aqr as well as mini-bursts and accretion arcs of variable size in HU Aqr. We report marked changes in the X-ray eclipse length of UZ For between high and low states.
The CHANDRA data of the Classical Nova RR Pic (1925): A possible Magnetic Cataclysmic Variable Candidate
Authors: Balman Şölen , Küpcü-Yoldaş Aybuke 
Published: July 2016

AbstractDuring 25ksec of CHANDRA ACIS-S3 observations of the old nova RR Pic 1925 a count rate of 0.067±0.0017 c/s was detected. The results show evidence (spatial and spectral) for X-ray emission from the region around the prominent SW blob in the Hα images. Shell emission is detected with count rate ≥ (1.95±1.33)×10−3 c/s. The spectral analysis shows that the source spectrum can not be explained by a single or two temperature bremsstrahlung or VMEKAL models including photoelectric absorption, only models using powerlaw distribution of temperature fit the data well and indicate excess O, Al, Mg, S, and Si in the source spectrum. A soft excess in the CHANDRA data could be explained by a partial covering absorber model with covering fraction in a range 14-86 % consistent with characteristics of the Magnetic Cataclysmic Variable systems. The light curve shows significant orbital and other modulations.
The Near-Synchronous Polar Candidate V4633 Sgr (Nova Sagittarii 1998)
Authors: Lipkin Y. , Leibowitz E. M. 
Published: July 2016

AbstractThe classical nova V4633 Sgr (1998) exhibits two photometric periodicities. The shorter period (P1=3.01 hr) is stable, while the other one, longer by ~2.5%, has decreased monotonically since shortly after the nova eruption, with Ṗ2 ≈ –10−6 (Lipkin et al. 2001).Here we report on results of photometric monitoring of the star in 2001 and 2002. During our observations, the longer period decreased more, and in 2002 it was only 1.8% longer than P1 The decrease rate (Ṗ2) in 2001-2002 was an order of magnitude smaller than in 1998-2000.These new results support the Near-Synchronous Polar classification which was suggested for V4633 Sgr (Lipkin et al. 2001). In this model, the longer period of V4633 Sgr is the spin of the white dwarf, and its variation since 1998 reflects changes in the moment of inertia of the white dwarf, and angular momentum transfer in the system following the nova eruption.
Multi-epoch spectroscopy, photometry and polarimetry of the polar UW Pic
Authors: Romero-Colmenero E. , Potter S. B. , Buckley D. A. H. , Barrett P. E. , Vrielmann S. 
Published: July 2016

AbstractOur multi-epoch observations show that UW Pic undergoes very pronounced changes in accretion geometry. We explain our observations in terms of changing accretion rates of UW Pic coupled with a particular orientation of the system to the observer.
Ultra-Short Period Double-Degenerate Binaries
Authors: Cropper Mark , Ramsay Gavin , Wu Kinwah , Hakala Pasi 
Published: July 2016

AbstractWe review the current observational status of the ROSAT sources RX J1914.4+2456 and RX J0806.3+1527, and the evidence that these are ultra-short period (< 10 min) binary systems. We argue that an Intermediate Polar interpretation can be ruled out, that they are indeed compact binaries with a degenerate secondary, and that the period seen in the X-ray and optical is the orbital period. A white dwarf primary is preferred, but a neutron star cannot be excluded. We examine the capability of the three current double-degenerate models (Polar, Direct Accretor and Electric Star) to account for the observational characteristics of these systems. All models have difficulties with some aspects of the observations, but none can be excluded with confidence at present. The Electric Star model provides the best description, but the lifetime of this phase requires further investigation. These ultra-short period binaries will be strong gravitational wave emitters in the LISA bandpass, and because of their known source properties will be important early targets for gravitational wave studies.
Unveiling the nature of the 321s Orbital Period X-ray source RX J0806.3+1527
Authors: Israel GianLuca , Stella Luigi , Covino Stefano , Campana Sergio , Marconi Gianni , Mauche Christopher W. , Mereghetti Sandro , Negueruela Ignacio 
Published: July 2016

AbstractA nearly simultaneous X-ray/optical (Chandra and VLT) observational campaign of RX J0806.3+1527 has been carried out during 2001. These observations allowed us to phase the X-ray and optical light curves for the first time. We measured a phase–shift of ~0.5, in good agreement with the presence of two distinct emission regions and with the X-ray irradiation process predictions. The Chandra data allowed us also to study in details the X-ray spectrum of RX J0806.3+1527, which is consistent with a soft (kT<70eV) and small (RBB <20km) black-body component. We discuss the present findings in the light of the models proposed so far to account for the X-ray emission detected from RX J0806.3+1527, and its twin source RX J1914.4+2456.
Optical Observations of Time and Latitude and the Determining of the Earth’s Rotation Parameters in 1980
Authors: Shu-Hua Ye 
Published: July 2016

This paper is based on optical observations of 85 instruments (Table 1-a) from January to October 1980. The accuracies of all instruments, 62 for time and 54 for latitude, are shown in Table 1-b, in which:–the roughness ε1i of daily observations is defined by the standard deviation of the observation values of the i-th instrument with respect to the smoothed values of themselves;–the ε2i is the standard deviation of mean observation values during every 0.05 year with respect to the global reference system.The average accuracy of each type of instrument is given in Table 2, regional averages are given in Table 3.These tables show that errors in time observations are greater, generally speaking, than those in latitude, and low frequency errors are greater than high frequency ones in time observations.
Rotation of the Earth From Lunar Laser Ranging
Authors: Langley R. B. , King R. W. , Morgan P. J. , Shapiro I. I. 
Published: July 2016

AbstractWe have extended our estimates of variation of latitude and UTO from the McDonald Observatory lunar laser ranging (LLR) observations to span the period October 1970 to November 1980. The typical formal uncertainties of our values are about 6 milliarcseconds (mas) and 0.5 milliseconds (ms) of time, respectively. We have compared our values of variation of latitude with those derived from the smoothed Circular D pole positions published by the Bureau International de l’Heure. The root-mean-square (rms) difference about the mean difference is 14 mas. A comparison of our smoothed UTO estimates with those calculated from the smoothed Circular D values of UT1 and pole position gives a corresponding rms difference of 1.5 ms. For the period covered by the MERIT Short Campaign, we have also compared our smoothed UTO values with (unsmoothed) ones derived from daily UT1 and pole-position values obtained by the Goddard Space Flight Center / Massachusetts Institute of Technology / Haystack Observatory group from very-long-baseline interferometric observations spanning two one-week periods. The rms difference about the mean difference is 0.3 ms.
Intercomparison of Lunar Laser and Traditional Determinations of Earth Rotation
Authors: Fliegel H. F. , Dickey J. O. , Williams J. G. 
Published: July 2016

AbstractThe rotational orientation of the earth (UTO at McDonald Observatory) has been determined from lunar laser ranging (LLR) measurements for the interval 1971 to 1980. The results have been differenced from those obtained by conventional means as published by the Bureau International de l’Heure (BIH), on its 1979 system. The difference displays a quasi-seasonal signature, which we ascribe to systematic errors in the conventional measurements. The lunar data are well represented by a smooth curve, which gives UTO at McDonald with a precision of about 3/4 milliseconds or better, and UT1 to within 1 millisecond using BIH polar coordinates.
Comparison of Polar Motion Results Using Lunar Laser Ranging
Authors: Dickey J. O. , Fliegel H. F. , Williams J. G. 
Published: July 2016

AbstractA comparison of polar motion results from three sources [Bureau International de l’Heure (BIH), Defense Mapping Agency Hydrographic/Topographic Center (DMAHTC-Doppler), the International Polar Motion Service (IPMS)] was performed using lunar laser ranging (LLR) data. The rms errors, both of the LLR data and of the determinations of polar motion by the three services, decreased in recent times. The BIH and Doppler polar motion are comparable in quality (12 ± 6 cm for BIH values taken from August 1976 through May 1980, 14 ± 7 cm for Doppler results taken from June 1977 through May 1980). The IPMS errors were substantially larger (33 ± 7 cm for data taken from August 1976 through May 1980). All three analyses give 13 ± 3 cm as an estimate for the combined LLR modeling, fitting, and instrumental error (noise) for the last four years.
Analytical Theories of the Motion of the Moon
Authors: Henrard Jacques 
Published: July 2016

AbstractAlmost every aspect of the analytical theory of the motion of the Moon has been reinvestigated lately. This paper is a review of these investigations.The improvement upon the I.L.E. (the best known earlier theory based upon the work of Brown) is spectacular, but it is still too early to assess the exact value of these theories with respect to numerical integration.
Numerical Studies of the Lunar Orbit at Cerga
Authors: Calame O. 
Published: July 2016

Until very recently the only available source of accurate positions for the Moon and planets were the american export ephemerides from JPL in particular DE86/LE40 which expired in May 1979 and then DE96/LE44 and DE102/LE51. Unfortunately, these ephemerides were constructed for various applications, but are not necessarily adapted for a purpose such as the EROLD program. Furthermore, these ephemerides are badly documented, which prevents having good homogeneity with the computations for the representation of the various motions of a lunar laser reflector with respect to a terrestrial station. Thus, in this framework, some other studies were useful.A few years ago, we decided that it would be desirable to support the Lunar Laser data reduction with the construction of a new ephemeris by numerical integration. This was considered valuable not only from the scientific point of view, but also as an operational tool for the EROLD and MERIT programs. Early in 1980, we adopted this ephemeris, called ECT 18, in the EROLD computations for the Annual Reports of BIH and for the needs of MERIT Operating Center and Analysis Center at CERGA.
Report on the Discussions on Library and Information Services in Astronomy During IAU Colloquium 110 (Washington, D.C., 1988)
Authors: Wilkins G.A. 
Published: July 2016

AbstractThis report provides an overview of the presentations and summarises the discussions at IAU Colloquium 110, which was held in Washington, D.C., on 1988 July 26-30 and at the Goddard Space Flight Center on 1988 August 1. The topics included: the publication and acquisition of books and journals; searching for astronomical information; the handling and use of special-format materials; conservation; archiving of unpublished documents; use of computers in libraries; astronomical databases and various aspects of the administration of astronomy libraries and services. Particular attention was paid to new developments, but the problems of astronomers and institutions in developing countries were also considered.
The Astronomical Publications in China
Authors: Jinming Liu 
Published: July 2016

At present there are three different kinds of astronomical publications in China: journals, observatory publications and special publications.Four journals are issued regularly: Acta Astronomia Sinica, Acta Astrophysica Sinica, Progress in Astronomy and Astronomy Amateur. There are five observatory publications available: Publications of Beijing Astronomical Observatory, Publications of Purple Mountain Observatory, Publications of Shannxi Astronomical Observatory, Publications of Yunnan Astronomical Observatory and Annals of Shanghai Observatory, Academia Sinica. Also several special publications have been published regularly, i. e. Chinese Solar-Geophysical Data (CSGD), Monthly Solar Activity, Time and Frequency Services Bulletin, Time Service Annual Report, etc.
The Revision of the Universal Decimal Classification for Astronomy
Authors: Wilkins G. A. 
Published: July 2016

AbstractThe Universal Decimal Classification system is widely used throughout the world for the arrangement of books in libraries and for the indexing of papers and reports as an aid to the retrieval of information. It is a comprehensive and language-independent system. The classification for astronomy and related topics (UDC 52) is used by many persons whose main interests are outside astronomy as well as by astronomical specialists. It is important that the classification be kept up to date, but the revision of UDC 52 is now overdue, as the last major revision was made in 1975 and published in 1977. It is clearly the responsibility of IAU Commission 5 to provide expert advice to the International Federation for Information and Documentation (FID) on the revision. Persons who are willing to participate in the work of revision are invited to write to the author, who is the current chairman of the relevant revision committee.
T-Rex: A Cooperative Thesaurus Building Project for the International Astronomical Union
Authors: Shobbrook Robyn M. 
Published: July 2016

Astronomers and librarians have been experiencing difficulties in keeping up with the amount of published literature. The astronomer tries to keep abreast in his particular field and the librarian in the management, control and retrieval of scientific information. The 1980’s have seen a revolution in the methods for information storage and retrieval and in particular the advent of the online database. The speed of processing information for storage has been embraced by all, however little thought has been given to how we shall achieve effective high precision recall of documents.Many librarians firmly believe the best road to success in information retrieval from automated systems is provided by vocabulary control. Contrary to belief, free text or natural language searching alone does not lead to high precision recall. Consistency and integrity of the online catalogue can only be achieved with the addition of a controlled vocabulary. With today’s technology it is possible to maintain the best of both worlds. The controlled vocabulary is used to index the major concepts of a given document over and above the natural language used within the document.
Handling of Preprints
Authors: Gómez M. E. 
Published: July 2016

At La Silla, we receive on average between 90 and 130 preprints a month from institutions all over the world. The preprints are extensively used by our staff as well as visiting astronomers who come to perform observations at La Silla. Most of the preprints are received as donations, others are requested directly from the publishing institute.The European Southern Observatory has among other publications, its ESO Scientific Preprints. At La Silla, the library does not deal with the distribution of these preprints, since this is made directly from ESO in Garching, FRG.
Non-Printed Materials
Authors: Jaschek C. 
Published: July 2016

Many modern catalogues and/or observing lists are too large for easy printing in a magazine, or have too short a life to be economically worth printing as a catalogue or a book. We have therefore two ways of presenting them:
(a)on microfiche(b)on tape (or diskette).One could add computer print-outs, but by experience there are mostly made for private use.Microfiches have never become very popular, although they are quite handy for long catalogues. The Henry Draper catalogue, weighting 10 kgs occupies 14 microfiches weighting 42 grams and can be accommodated in a common envelope. Durability of good microfiches is guaranteed for several decades and its price is cheap. Except thus for the reading device, which is bulky, the microfiche is a handy way to store information, especially when only small amounts of information are to be retrieved.
Observatory Publications and their Significant Role in Astronomical Libraries
Authors: Kaminska Kinga 
Published: July 2016

The Library of Warsaw University Observatory is a small one, but it is one of the oldest astronomical libraries in Poland. The library collection has been gathered almost since the beginning of the Warsaw Observatory, that is since 1825. Although a large part of our collection was burned during the Second World War, the remaining part contains many unique items. Scholars doing research in the area of the history of astronomy often find our collection very helpful in their work.Observatory publications play a significant role in my library. In general, we have limited possibilities for buying publications with hard currency. Therefore, any free publications obtained by my library constitute an extremely valuable source of information about new research and discoveries all over the world.
Correspondence, Unpublished Papers and Data: Comments on Modern Use of Old Archives
Authors: Debarbat Suzanne 
Published: July 2016

For a scientific or historical purpose, nowadays astronomers may need to use documents of the past. On can assume they are then, in a situation similar to the one that next centuries searchers will have to face, when using present time documents we will have left them. So, actual experience may help to know what to do or what not to do, dealing with the contents of future archives.In astronomy, the most important variable is time. Since in this field, no experiment can be made, the astronomers must watch the universe and an essential task is to observe. Starting from observations, they will set up theories through analysis, treatment, interpretation, or else, starting from theoritical work, they will check their conclusions by comparison with observational data.
Computer System of Library Management and Information Retrieval at the Shaanxi Astronomical Observatory
Authors: De-he Li , Ya-hong Wang , Fa-kuan Dang , Jun Chen , Feng-xiang Chen , Yu-lian Wang , Qiu-ju Xu 
Published: July 2016

For modern management and full resource sharing among libraries and scientific departments both in Chinese and worldwide observatories, we established the computer system of library management and information retrieval during the period 1984-1987.The system is composed of ten component sub-systems:
1.Book ordering system. This system can produce orders for books and periodicals, balance accounts, produce statistics as well as claims for outstanding book orders.2.Book cataloguing system. This system can catalogue books under certain rules while appending new records of books to the databases. It can also produce catalogue cards and produce written reports about the new books.3.Book retrieval system has the ability to search for a specific book in several ways.4.Book lending or circulation system. This system is a complete circulation system; including book lending, renewals, waiting lists, and recall of borrowed books.5.Periodical management system. This system is in charge of processing of periodicals and magazines in the library, including cataloguing, management, and lending.6.Scientific information retrieval system. One can retrieve scientific information by keywords or in many other ways.7.Internal material booking system. It can make orders of internal materials, claims for materials outstanding and make exchanges with other observatories and institutions both in or outside the country.8.Internal material management system. It can do the work that is analogous to that done with books and periodicals.9.Information relationship system. It handles exchanges of information between institutions. Computer system of library management ... at Shaanxl 18310.Scientific information network management system. It manages affairs within a certain information network.
Resource Sharing and Cooperative Activities in Astronomical Libraries
Authors: Lastovica Ethleen 
Published: July 2016

The Shorter Oxford English Dictionary defines “resource” as ‘A means of supplying some want or deficiency; a stock or reserve upon which one can draw when necessary’. The Collins English Dictionary further defines “resources” as ‘a source of economic wealth especially of a country or business enterprise (capital,equipment,personnel,etc.)’.The essential theme of this Workshop is resource sharing because it has been organized to provide an opportunity for librarians of astronomical observatories and institutions to meet to discuss common problems and ways of stimulating greater cooperation between libraries in different countries. The White House Conference on Library and Information Services held in 1979 outlined the justifications for resource sharing by stating:... ‘resource sharing is now mandated by the information explosion, the advance of modern technology, the rapidly escalating costs of needed resources, and the wide disparity between resources available to individuals by reason of geographic location or socio-economic position’.
Physics and Mathematics Acquisitions in French Libraries Specialized in Astronomy: Some Comments
Authors: Vin M.J. , Motais de Narbonne A.M. 
Published: July 2016

The importance of physics and mathematics in astronomical research has been growing for the last twenty years; yet, the volume of book acquisitions in the relating fields has been decreasing in most french libraries specialized in astronomy (graph 1).Great are the consequences of the physics book high prices (graph 2) on the acquisition volume and more drastic is the selection when the total amount of acquisitions is low, i.e. in small libraries (graphs 3 and 4). Yet, the restriction of acquisitions has not generated increasing inter-library loans in the relating fields and national service (CADIST) acquisitions in physics and mathematics have also been dropping. This point, connected with the concomitant general growth of astronomical book accessions, leads us to explain the contradictory observations as mentioned above here from the astronomical publication contents.
Light Pollution – A Problem for All of Us
Authors: Crawford David L. 
Published: July 2016

ABSTRACTLight Pollution is a severe problem for amateur and professional astronomers, and, indeed, for the general public. All these suffer from a lack of awareness of the issues, however. Poor quality outdoor nighttime lighting has several major problems: light trespass, glare, clutter and confusion, urban sky glow, and energy waste. There are solutions to the light pollution problem, most involving the use of better quality lighting. We all must educate our colleagues and the public about the issues, and push for solutions. Quality lighting is compatible with dark skies, and with energy savings. Our view of the universe, as professionals and as the public, and our children’s, depends on our being successful.