bluuebunny/crossref_metadata_2025 huggingface dataset:
The Teaching of Astronomy in China
Authors: Ke-Jia Feng
Published: July 2016

Astronomical education has been developing at an increasing rate in China since 1977. Many Chinese astronomers think that the development and the popularization of astronomical education are future human needs. For this reason, we use radio and TV broadcasts as well as planetariums to popularize astronomical education in our country. The teaching of astronomy is enhanced in schools step by step. For elementary schools many astronomical topics are included in a course under the general title of Nature. Some activities such as astronomical observation and courses of astronomical lectures are organized in secondary schools. In universities, elective courses of astronomy are arranged not only in some departments of natural science but also in some departments of liberal arts. Some students in other scientific departments are encouraged to take astronomical courses, so that universities can supply frontier science with researchers.
Curriculum for the Training of Astronomers: Comments
Authors: Caton Daniel B.
Published: July 2016

In this first international meeting on the teaching of astronomy, we should not only look at many specific techniques and approaches but also examine the overall process. In doing so, several general problems come to light and need to be commented upon:

1.

Introductory astronomy course lab exercises are often lacking in rigor, compared to labs in other physical sciences. Students are often asked to do simple, qualitative exercises like drawing the moon or constellations – projects that bear more resemblance to 19th-century astronomy than to the work of modern science. Lab programs should be modernized, taking advantage of modern telescopes and ancillary instrumentation.

2.

A survey taken of U.S. astronomy department chairs, in preparation for an American Astronomical Society roundtable discussion, revealed a wide spectrum of approaches to undergraduate astronomy instruction. The one single obvious result of the survey was the recognition of a need for an international survey, with the results distributed and discussed by the participants. The dispersion of programs may also suggest another need ....

3.

The astronomy instructional community lacks a central journal for the publication of pedagogical articles. The physicists have the American Journal of Physics and the Physics Teacher for advanced and lower-level articles, respectively. While astronomical articles appear in these from time to time (as well as in other publications), there is no single publication that educators can depend upon to contain important articles. While there is probably too little material available to form a new journal or newsletter, perhaps educational sections could be started in the Publications of the Astronomical Society of the Pacific, Mercury, or Sky & Telescope.

4.

Astronomy students (majors) are often told to “get a physics (undergraduate) degree” in preparation for becoming an astronomer, yet strongly desire to take astronomy courses. This dual-program requirement results in either larger course loads (to include the astronomy), or the possibility of losing them to other disciplines. Students can perhaps be kept interested by involving them in astronomy research while they are learning their basic math and physics.
The Thrill of Discovery
Authors: Verschuur Gerrit L.
Published: July 2016

In the process of communicating to the student or the lay person, we often forget to point out why it is that scientists are involved in their esoteric explorations of the universe. As a result, the scientific endeavor is painted as being somewhat removed from “real life.” This unfortunate misconception can be remedied by discussing the thrill of discovery.

Scientists love to “boldly go where no man has gone before.” The act of discovery produces a heady sensation akin to the thrill of victory for an athlete. The thrill may come as a surprise, as the result of a serendipitous turn of events, or may be experienced at the conclusion of a dedicated piece of research whose end-point was always understood. In either case the joy is associated with the revelation of what was previously unknown or not understood. It is this joy that is the reward for the researcher.
Starting Out: The Dilemma of the Beginning College Astronomy Teacher
Authors: Shipman Harry L.
Published: July 2016

Most beginning college professors in the United States receive little if any help in the important task of learning how to teach well. Occasionally, a colleague or department chairman can provide some guidance, but in general most American college faculty are taught how to teach by the “sink or swim” method. There are many resources that can help the new professor swim, rather than sink, but in my case at least, I found out about them many years after I needed them the most. This paper will identify some of the literature, journals, and on-campus facilities that can help both new and experienced faculty members develop and hone teaching skills.

The literature on teaching and learning is vast. Fortunately, the new teacher need not spend years becoming an expert on this literature; much of it is like the astronomical research literature in that it is full of jargon and it requires some expertise to distill useful, easily implementable ideas from it. Fortunately, there are a few (too few!) books that distill this vast literature into practical advice from it.
Teaching 7000 Students Per Year
Authors: Robbins R. Robert
Published: July 2016

The undergraduate program at the University of Texas has grown into the largest astronomy teaching program in the world, with some 7000 students per year (almost 20,000 credit hours). The department has 22.5 Ph.D.-level teaching faculty, about 45 graduate students, and about 40 pre-professional undergraduate majors. But most of the enrollment is in courses that satisfy the science requirements of students in liberal arts and non-technical majors. In 1985–86, 96.4 per cent of our undergraduate credit hours taught were in such classes. It is instructive to examine the historical reasons for our growth and its educational consequences, and to draw some conclusions from both for other programs.
Telescopes for Students
Authors: Bishop Roy L.
Published: July 2016

An astronomy class typically is composed of twenty or more students, one instructor, and one telescope. For observing sessions, these numbers mean that at any one moment most of the students are standing, slowly freezing in the dark, waiting their turn at the eyepiece. Moreover, when they do have their 20-second peek, moist breath, a bump by the last observer, or unfamiliarity with the instrument often mean that the object will look hazy, be out of focus, or even be out of view. A couple of sessions under these circumstances can dampen the interest even of keen students. Also, the instructor may be reluctant to let individual students have unsupervised access to the one, expensive, fragile telescope.
Microcomputers in an Introductory College Astronomy Laboratory: A Software Development Project
Authors: Meisel David D. , Kinsey Kenneth F. , Recchia Charles H.
Published: July 2016

We have developed software for the Apple IIe series of microcomputers for use in labs in an introductory astronomy course. This software emphasizes a toolkit approach to data analysis; it has been class tested with over 170 students and was a resounding success as a replacement for previously used graphical approximations. A unique feature of this software is the incorporation of image-processing techniques into a course designed for non-science majors.

The five software packages are:

(a)

Datasheet - A six-column spreadsheet with columnwise operations, statistical functions, and double-high-resolution graphics.

(b)

Image-Processor Program - Allows 37 × 27 pixel × 8 bit video captured images to be manipulated using standard image-processing techniques such as low pass/high pass filtering and histogram equalization.

(c)

Picture-Processor Program - Allows 256 × 192 bilevel pictures to be manipulated and measured with functions that include calipers, odometer, planimeter, and protractor.

(d)

Orrery Program - Simulates planet configurations along the ecliptic. A movable cursor allows selection of specific configurations. Since both relative times and angular positions are given, students can deduce the scale of the solar system using simple trigonometry.

(e)

Plot Program - Allows orbital positions as observed from above the pole to be plotted on the screen. By entering trial values of elliptical orbit parameters, students obtain and the program plots the best fitting ellipse to the data. The sum of the squares of the residuals in the radial coordinate is given after each trial so that students can discover convergence more easily than by simple visual examination of a plot comparing the trial theoretical points with the raw data points.
Astronomy in American Textbooks
Authors: Pasachoff Jay M.
Published: July 2016

Over the last dozen years, I have written textbooks on a variety of levels, starting with books for university students, proceeding to work with Naomi Pasachoff on books on the junior-high level, and, most recently, working with her and with others on an elementary-school series. I can testify that, in the United States, at least, the world of college and university texts is as different from the world of “el-hi” (elementary-high) texts as night is from day.
Two Innovative Devices for the Teaching of Astronomy
Authors: Szostak Roland
Published: July 2016

The teaching of astronomy in schools should start by explaining the most elementary phenomena, which are a part of everyone’s daily experience. Before proceeding to advanced topics, teachers of astronomy in school have to make sure that these very basic phenomena are fully understood. Since many programs have a gap at the elementary level, many people have foggy notions or disconcertingly wrong ideas of elementary matters. The seasons are a well-known case of a badly-understood phenomenon even for highly educated people. Still these people are honest and should not be laughed at. They do not understand the basic concepts of our contemporary scientific world, simply because these topics have not been taught properly. This problem raises a challenge for developing better ways of teaching astronomy. In order to show that there are specific new solutions to this challenge, I am presenting two innovative devices, which have been developed at the Universität Münster . The first example shows how the seasons may be successfully explained with a physical model that changes color when heated. The other example refers to the visibility of the stars and their disappearance in the daytime.
The R.A.S.C. Observer’s Handbook
Authors: Bishop Roy L.
Published: July 2016

Except for two years, 1909 and 1910, the Observer’s Handbook of The Royal Astronomical Society of Canada has been published every year since 1907. It was founded by Clarence Augustus Chant, who also was responsible for the founding at the University of Toronto, of Canada’s first and largest department of astronomy, and who established the David Dunlap Observatory, which contains the largest optical telescope in Canada. In addition, Chant served as Editor of the Observer’s Handbook for 50 years, which is the main reason I am only the fourth editor since 1907. I should mention that John Percy, Chairman of the Scientific Organizing Committee of this Colloquium, was the third editor.
Clea: Aims and Activities
Authors: Gouguenheim L. , Bottinelli L. , Dupré J. , Gerbaldi M.
Published: July 2016

The Liaison Committee between School-Teachers and Astronomers (in French, “Comité de Liaison Enseignants Astronomes” or CLEA) was officially created about ten years ago under its present form, but its story began in 1970. In that time, there was no astronomy at all in French school programs, neither in elementary nor in secondary schools.

A discussion was beginning about introducing physics earlier in the curriculum, with a specific purpose, the main ideas being (i) to avoid too much formalism (and formalism is a strong general characteristic of French science teaching) and (ii) to concentrate on experimentation and on the various representations of natural phenomena.
An Example of Clea Activities in the Training of School Teachers
Authors: Bottinelli L. , Dupré J. , Gerbaldi M. , Gouguenheim L.
Published: July 2016

Various simple activities are being developed by the French Comité de Liaison Enseignants Astronomes (CLEA) in the training of school teachers. We give in the following one example of a very simple instrument which we call “Alphonse’s box,” after Alphonse Delavergne who invented it. It is also called a heliograph. This very simple and inexpensive instrument enables (1) the plotting of the daily apparent path of the sun, (2) the determination of the duration of sunlight, and (3) the determination of the declination of the sun. The following description is due to Maryse Jonas:

1. photosensitive paper (used by architects) that can be handled in semi-darkness; its sensitive face is yellow and it is developed by the vapor of an ordinary ammonia solution in about ten minutes;

2. a simple can, with a cover that will shut tight; approximate dimensions: diameter 10 cm, height 15 cm, with a hole about 0.5 mm in diameter on one side;

3. two pieces of wood, 15 x 15 cm and 15 x 20 cm; one butt hinge; one threaded rod with two nuts and two washers.
Training of School Teachers at French Astronomy Summer Universities
Authors: Gerbaldi M. , Bottinelli L. , Gouguenheim L. , Delmas F. , Dupré J.
Published: July 2016

In September 1976, at the end of the IAU General Assembly held at Grenoble (France), a one-day meeting concerning the teaching of astronomy was organized by Commission 46. It was decided during this symposium, which brought together 150 French school teachers and 50 astronomers, among other things, to organize a summer school of astronomy the following summer. Since then, such a school has been organized every summer. These astronomy Summer Universities are one of the activities developed by the non-profit organization CLEA (Comité de Liaison Enseignants Astronomes) whose activities are discussed elsewhere in these proceedings. In astronomy, children are always very curious. Because of this interest, in the 1970’s some French astronomers applied pressure on the Education Ministry to introduce the subject in schools, and they were successful. However, astronomy was not introduced as a new separate subject, but rather as a part of another subject, mainly mathematics or physics.
An Astronomy Course for Mexican High-School-Level Teachers
Authors: Herrera M.A.
Published: July 2016

In 1985, the National University of Mexico (UNAM) created a series of updating courses for high-school level teachers, both as an answer to an explicit demand of the teachers themselves, who asked for “fresh” information in their fields, and as an effort to improve the general level of undergraduate students, whose grades in the entrance examinations to the University had been secularly decreasing for years. To date, three “packages” of intensive 50-hour courses have been offered (during the three summer vacation periods) and Astronomy has been present in all of them. However, it should be mentioned that this presence was due only to the personal interest of the director of the project, since the subject “Astronomy” is not included in the official programs. In the following, we present a brief description of the courses and some interesting results.
The Contribution of Amateur Astronomers to Astronomy Education
Authors: Iwaniszewska Cecylia
Published: July 2016

I would like to dedicate this paper to the memory of my husband, Henryk Iwaniszewski, an astronomer working in radio astronomy and electronics, who until his untimely death seven years ago had been very active as president of our local branch of the Polish Amateur Astronomers Association. He was especially keen about introducing astronomy to the general public.

I want to speak here mainly, but not exclusively, about the IAU Colloquium No. 98, “Contribution of Amateur Astronomers to Astronomy,” which was held in 1988 in Paris. First of all, some definitions. Thomas Williams of the American Association of Variable Star Observers (AAVSO), from Houston, Texas, introduced at the conference several criteria for identification — first of astronomers, and then of professionals and amateurs. According to Williams:
Extragalactic Objects: An Example of Popularizing Astronomy for the Amateur Astronomer
Authors: Feitzinger J.V.
Published: July 2016

The handbook Astronomy (Handbuch für Sternfreunde), edited by G.D. Roth, will soon appear in its fourth edition. Newly written by 25 authors, the two volumes contain an additional chapter: Extragalactic Objects. The intention of my 50-page contribution to these volumes is to show the amateur astronomer that extragalactic work is not disappointing, ending in the northern sky with a fuzzy picture of the Andromeda Nebula.

The former editions of Roth’s handbook were mainly characterized by the statement that the observation of extragalactic objects is beyond the capabilities of the amateur. In the last ten years the situation has drastically changed, especially because of new photographic techniques and sensitive emulsions and the availability of CCD’s even for amateur astronomers. Small telescopes are no hindrance to doing interesting extragalactic work.
The Popularization of Astronomy in Mexico
Authors: Fierro Julieta
Published: July 2016

Mexican professional astronomers have a great task ahead if they want to popularize astronomy. We are very few and the country has great educational needs, with 4 years of elementary school being the average educational level.

In order to overcome this challenge, the Institute of Astronomy of the National University has popularized astronomy using the following resources: 1) publications, 2) public lectures, 3) advice to museums and planetariums, 4) radio and television interviews, and 5) courses.
Astronomy Courses for Adults in Sydney, Australia
Authors: O’Byrne J.W.
Published: July 2016

The University of Sydney has been associated with adult education courses for the general public for at least 70 years and astronomy has often been a part of this activity. Since 1976, these courses have been conducted by a succession of graduate students from the Astronomy and Astrophysics departments within the university. The courses were a part-time activity conducted with limited resources, but served as useful teaching experience. This arrangement continued until the end of 1987 when I left the university. I am pleased to report that this activity is considered sufficiently important to be continued by the permanent academic staff.

Here I seek to briefly report on these astronomy courses by describing those that I conducted at the university over the last five years. I should firstly acknowledge the work of Dr. Graeme White in particular, for his earlier courses and continuing interest. Also, this discussion should be placed in context by recognizing that other astronomy courses are run in Sydney by professional and amateur astronomers through local evening colleges and other organizations. These vary in format, with many of the amateur-run courses emphasizing the practical aspects of sky observing. The displays and facilities provided by the Sydney Observatory also play an important role. Each activity helps to meet the demand in the Sydney region for astronomical education and thereby undoubtedly serves the interests of Australian astronomy.
Programs of I.A.U. Commission 46 for Developing Countries
Authors: Wentzel Donat G.
Published: July 2016

ISYA typically last about three weeks and attract roughly twenty students at the Master of Science level. About half the students are from the host country, the others from neighboring countries. ISYA are initiated by astronomically developing countries and have been held in Venezuela, Nigeria, Egypt, Portugal, Yugoslavia, Indonesia, China, and others. Two or three central topics are chosen. For each topic, a suitable faculty member is invited to stay for the entire school. Other topics appear for enrichment and are chosen according to local expertise and availability of other visitors. The IAU provides the prestige of an international venture and seeks to garner local support not only for the ISYA but also for the longer-term increase in local astronomical capabilities. Financial support is provided both locally and by the IAU, when possible ultimately from UNESCO. Perhaps the greatest benefits of an ISYA are the resulting lasting acquaintances and scientific cooperations.
Urania Observed
Authors: Fernandez Rafael , Pasachoff Jay M. , Volz Robert
Published: July 2016

The public interest in astronomy, so often cited in this Colloquium, is demonstrated by the many works of art over the centuries with astronomical content. We mounted an exhibition, named Urania Observed after the muse of astronomy, at the Clark Art Institute to coincide with IAU Colloquium #105 on the Teaching of Astronomy and with the Sesquicentennial of the Hopkins Observatory. We thank Wayne Hammond of the Chapin Library for his expert assistance with this exhibition.
The Hα Emitting Regions of the Accretion Disks in Algols
Authors: Peters G. J.
Published: July 2016

The circumstellar plasma that produces Hα emission in Algol binaries has been investigated using phase-resolved, high dispersion data acquired from CCD and image tube detectors. Results are summarized in this paper, including discussions of the disk geometry and size, asymmetry in the distribution of material, long-term or non-phase dependent variability, mass outflow, the mean electron density, and how the latter properties vary with the system’s period or location in the r - q diagram. Five systems which display permanent emission with periods ranging from 4.5 to 261 days (SW Cyg, UX Mon, TT Hya, AD Her, and RZ Oph) are intercompared. If P < 4.5 days, no permanent disks are observed, while if P > 6 days, stable disks with only slight long-term variations in their Hα brightness are seen. The most variable systems appear to be those in the 5 - 6 day range, but the star’s position in the r - q diagram has the largest influence on its behavior. The trailing side of the accretion disk, where the gas stream impacts the inner disk, is usually brighter, and the leading side is often times more extended. The disk extends out to at least 95%of the Roche surface of the primary and is highly flattened (≤Rp). Mass outflow near phase 0.5 is commonplace.
Photometric Effects of Accretion Disks in Long-Period Eclipsing Binaries
Authors: Olson Edward C.
Published: July 2016

Accretion disks are invoked in a variety of astrophysical settings, ranging from stellar-mass black holes to active galactic nuclei. There is now little doubt that true accretion disks can also occur in binaries containing non-degenerate stars (Peters 1980; Plavec et al. 1984; Polidan 1987). In this paper, I will discuss some of the properties of disks observed photometrically in the long-period systems KU Cyg and RZ Oph.

The most intensively-studied disks are of course those in cataclysmic binaries. Accretion disks in such binaries are thought to have the classical ′alpha′ structure of Shakura and Sunyaev (1973), in which viscous dissipation arising from differential rotation converts gravitational potential energy to thermal energy in supplying the disk luminosity. This physical process requires that the viscous time scale be comparable to the radiative decay time of the disk (Pringle 1981). Most of the disk′s volume is optically thick, so disk luminosity is estimated by integrating black-body or stellar atmospheric fluxes over the disk (see Kriz and Hubeny 1986 for qualifications).
Radio Emission from Selected Algol Systems
Authors: Umana G. , Catalano S. , Rodonó M. , Gibson D. M.
Published: July 2016

Radio emission from close binary systems has long been detected in Algol and other systems. RS CVn systems have been found to be the most powerful and active. The RS CVn binaries are also known to show strong chromosferic and transition region emission line fluxes, that are one or two orders of magnitude higher than those from single stars of similar spectral type. This enhanced activity seems to be connected to the rapid rotation due to the tidal interaction in the system. The Algol binaries are semi-detected close binary systems formed by an early type main sequence primary and a late type giant secondary, while in the RS CVn both components are late type stars of about the same mass, the secondary being a giant or subgiant.

The Algol binaries and RS CVn differ also in their evolutionary history. However, since the spectral type and probably the internal structure of the secondary components of Algols appear to be similar to that of the secondaries of RS CVn systems, and they both are synchronous fast rotators in close binaries, we would also expect that the secondaries of Algol systems to show some kind of activity.
Matter Streams in Algol-Like Systems
Authors: Wonnacott D.
Published: July 2016

Simulations of the Algol-like binary CX Draconis, combined with IUE observations of the stream of material escaping the system can place limits on the inclination of the system and give estimates, via line profile synthesis, of the mass-loss rate at the L1 point.
Photometric Study of two Southern Algol Type Binaries
Authors: Abhyankar K. D. , Vyas M. L.
Published: July 2016

Complete UBV light-curves of RR-Lep and RX-Hya have been obtained during 1983-87 seasons. Preliminary elements were computed using modified Wellmann’s method. With these parameters as inputs Wilson-Devinney program was executed for Blue and Yellow passbands simultaneously in detached and semi-detached modes for both the systems. The semidetached mode fitted better than the other solution for both the systems. For RR-Lep, the absolute dimensions were computed by assuming the primary to be a slightly evolved main sequence star. For RX-Hya, the absolute dimensions were computed using Struve’s spectroscopic data. The following table gives all the elements for both the systems. The secondaries of both the systems are overluminous for their masses suggesting that they have lost considerable mass.
Duplicity on the Main Sequence
Authors: Herczeg T.
Published: July 2016

A review paper or a lecture like the following one, will best serve ‘its’ conference by giving an overview of the basic facts, and an impartial review of current debates, also by trying to point out some apparently crucial questions whose solutions, we hope, will determine the line of future research.

Because these stars are essentially unevolved, beyond the topic of multiplicity on the Main Sequence looms the fundamental problem of the formation of binary star systems. Thus we are going to concentrate on the following questions: the fraction of stars that are formed in binary and multiple systems, the distribution of mass ratios for unevolved systems, the role of very wide pairs and the smallest known stellar or substellar masses. We will pay special attention to nearby binary stars. On the other hand, we do not have the space to discuss in any detail the binaries in extragalactic systems, in the upper regions of the HR-diagram; they are practically all evolved systems.
Fission Sequence and Equilibrium Models of Rigidity Rotating Polytropes
Authors: Hachisu Izumi , Eriguchi Yoshiharu
Published: July 2016

Equilibrium sequences of self-gravitating and polytropic stars including binary stars are computed for various polytropic indexes. We find a fission sequence from an ellipsoidal configuration to a binary by way of dumb-bell equilibrium.
Fission Candidates Among Detached Close Binaries
Authors: Ott H.-A.
Published: July 2016

A comparison between results of model calculations and observed properties of close, but detached low mass binaries with Main Sequence primaries shows statistical trends, which seem to support fission origin for some of these objects: the mass-momentum relation, the relation between mass ratio and separation and the relation between mass ratio and synchronisation speak in favour of close initial separations and small mass ratios of the components.
VV Orionis: A Well-Behaved Early-Type Eclipsing Binary System
Authors: Chambliss Carlson R.
Published: July 2016

VV Orionis is a detached eclipsing binary system consisting of stars of spectral types BI V and B4 V with a period of l.d4854. There is also a third component whose orbital period about the eclipsing pair is about 120 days. In recent years there have been several new photoelectric and spectroscopic investigations of this system, and the results of these are compared. Both the geometric and photometric orbital elements appear to be well determined. VV Ori A appears to be of normal size and mass for its spectral class, but VV Ori B seems to be somewhat smaller than would be expected for a normal B4 V star. Linear limb-darkening coefficients are derived for VV Ori A, and these are in good agreement with theory. This system is of particular importance, because it is only one of very few early-type systems for which reliable limb-darkening coefficients can be expected to be obtained. The contribution of the light of the third component to the system has also been determined, and it appears most likely that VV Ori C is a star of spectral type A3 V.
Photometry of the RS CVn Type Eclipsing Binary UV Piscium
Authors: Rao P. Vivekananda , Sarma M. B. K.
Published: July 2016

The analysis of the UBV photoelectric study of the short period RS CVn eclipsing binary, UV Psc, has suggested that the primary is a transit with ɵe = 27°, i = 88.°5, and k = 0.75. The spectral type and luminosity of the hotter component is estimated to be G4-6V and that of the cooler component to be K.0-2V. Absolute dimensions for the components of UV Psc were derived by combining the present analysis with that of the spectroscopic analysis given by Popper.

The out-of-eclipse observations have showed large amount of scatter and an investigation of this showed that hotter component could be an intrinsic variable. No periodicity for this variation has been fixed due to lack of sufficient data.
Variable, Optically Thick, Hot Plasma Observed in Interacting Binaries
Authors: Kondo Y. , McCluskey G. E. , Parsons S. B.
Published: July 2016

We report recent International Ultraviolet Explorer (IUE) observations of two interacting binaries, R Arae and HD 207739. The ultraviolet spectra indicate the presence of optically-thick, variable hot plasma in those binary systems. These two binaries may belong to a class of binaries that are currently undergoing a rarely observed and probably short-lived phase in their evolution. Their properties are compared with those of two other interacting binaries, U Cephei and ß Lyrae.
Periods Ranging From 5 to 1500 Days in the Anticorrelated Moving Lines of SS 433
Authors: Frasca S. , Ciatti F. , Mammano A.
Published: July 2016

Some tens of harmonic components are found in the moving lines of SS 433, leaving a standard deviation of 0.002 in Z units, that is comparable to the observational error.

Ten harmonics appear anticorrelated in the two branches, among which those at 80,155, and 1500 days are also strong. Their behaviour indicates changing structure in the ejecting mechanism.

No secular change is occurring in the precessional 163-day period beyond the estimated error of 5 x 10-5 d-1. No periodicity occurs in beam velocity. One quarter of cases of (Z1 + Z2) are found outside their mean value by more than 5σ. This implies either variable beam velocity or absence of strict anti-parallelism.
Late Stages of the Evolution of Close Binaries
Authors: De Loore C. , Sutantyo W.
Published: July 2016

Close binaries can evolve through various ways of interaction into compact objects (white dwarfs, neutron stars, black holes). Massive binary systems (mass of the primary M1 larger than 14 to 15 M0) are expected to leave, after the first stage of mass transfer a compact component orbiting a massive star. These systems evolve during subsequent stages into massive X-ray binaries. Systems with initial large periode evolve into Be X-ray binaries.

Low mass X-ray sources are probably descendants of lower mass stars, and various channels for their production are indicated. The evolution of massive close binaries is examined in detail and different X-ray stages are discussed. It is argued that a first X-ray stage is followed by a reverse extensive mass transfer, leading to systems like SS433, CirXl. During further evolution these systems would become Wolf-Rayet runaways. Due to spiral in these system would then further evolve into ultra short X-ray binaries like CygX-3.

Finally the explosion of the secondary will in most cases disrupt the system. In an exceptional case the system remains bound, leading to binary pulsars like PSR 1913 +16. In such systems the orbit will shrink due to gravitational radiation and finally the two neutron stars will coalesce. It is argued that the millisecond pulsar PSR 1937 + 214 could be formed in this way.

A complete scheme starting from two massive ZAMS stars, ending with a millisecond pulsar is presented.
Analysis of 11 Late-Type Close Binary Systems
Authors: Lfung K. C. , Zhai D. S. , Zhang R. X. , Liu Q. Y. , Zhang J. T. , Yang Y. L.
Published: July 2016

This is a preliminary report on the joint research project between 3 observatories: Beijing, Yunnan, and Behlen Observatories from China and the United States. The systems we have been dealing with are primary of late spectral types and with short periods. Most.of the observations were secured from the observatories in China. The computational analysis is carried out in University of Nebraska, Lincoln. The photometric solutions are based on the Wilson and Devinney method. Out of 11 systems analyzed 6 of them: AO Cam. ER Ori. BX Peg, BB Peg, U Peg, and SW Lac are found to be contact systems. All of them are having their primary eclipses at occultation. Therefore they can be classified as W-type WUMa systems. They also show other W-type characteristics.
Astrometric Observations
Authors: Roemer Elizabeth
Published: July 2016

If one wants to study the physical characteristics of individual asteroids, he must first find them and be prepared to track them accurately during observation. To make the necessary predictions, the positions of asteroids are measured in reference frames defined by stars of known coordinates as the input information for calculation of orbits and ephemerides. Continuation of positional observations over lengthening arcs provides the basis for improvements of orbits and increased accuracy of ephemerides.
The Physical Meaning of Phase Coefficients
Authors: Veverka J.
Published: July 2016

The question of what information about an asteroid's surface is contained in a measurement of the phase coefficient between phase angles of 10° and 30° is examined in detail. Contrary to some past claims it is shown that absolute reflectivities cannot be derived from phase coefficients. Furthermore, typical asteroid phase coefficients cannot be interpreted unambiguously. This is because the observed phase coefficient may depend as much on the photometric properties of an individual surface element as on the degree of large-scale surface roughness, and these two effects are impossible to separate if only disk integrated measurements are available. The wavelength dependence of asteroid phase coefficients should be small and should contain little information about the surface. In the case of irregular asteroids with macroscopically rough surfaces, the importance of large-scale shadowing, and hence the observed phase coefficient, will depend on the aspect of the asteroid. In such cases, therefore, phase coefficients must be carefully defined to be meaningful It should be possible, in some cases, to estimate the relative surface roughness of two quasi-spherical asteroids by combining photometric and polarimetric observations. For example, if the two asteroids have almost identical polarization curves but quite different phase coefficients, it is likely that the asteroid with the larger phase coefficient has a macroscopically rougher surface.
624 Hektor: A Binary Asteroid?
Authors: Cook A.F.
Published: July 2016

Dunlap and Gehrels (1969) have published lightcurves of the Trojan asteroid 624 Hektor. They proposed a conventional explanation in which Hektor is regarded as having the shape of a cigar. Two circumstances suggest, but do not prove, that Hektor is a binary asteroid. (1) The cigar shape at the conventional density of stony meteorites (3.7 g-cm-3) appears to produce stresses that may well exceed the crushing strength of meteoritic stone. (2) The lightcurves exhibit an asymmetry changing with time that suggests librations of two ellipsoidal components. Observations are clearly required to look for these periodicities when we shall again be nearly in the plane of Hektor’s revolution (or rotation) in 1973. An additional supporting lightcurve is desirable in 1972 and also in 1974. The periods of libration are probably nearly 1 day, if they exist, so that observations should be made from more than one geographic longitude in 1973. The present paper is an exposition on these considerations.
Fragmentation and Distribution of Asteroids
Authors: Dohnanyi Julius S.
Published: July 2016

As a result of mutual inelastic collisions, frequent on a geologic time scale, the mass distribution of asteroids undergoes constant change. Using a simplified velocity distribution for asteroids, the redistribution of their masses caused by collisions can be mathematically modeled as a stochastic process and the distribution of asteroidal masses can then be obtained as the solution. This paper is a review of recent progress on this problem.

The most detailed discussion of this problem considers the influence of the following collisional processes on the asteroidal mass distribution: (1) loss of asteroids by catastrophic breakup, (2) creation of new objects from the fragments of a catastrophically disrupted one, (3) erosive reduction in the masses of individual asteroids, and (4) erosive creation of new objects (i.e., production of secondary ejecta during erosive cratering by projectiles not large enough to catastrophically disrupt the target object). The main result is that after a sufficiently long period of time the population of asteroids may reach a quasi-steady-state distribution, regardless of the initial distribution. This final distribution is a product of a slowly decreasing function of time by a power law of index 11/6 for masses smaller than the largest asteroids. For the largest asteroids, an additional factor is included that expresses the influence on the distribution of the absence of masses larger than those observed. The observed distribution of bright asteroids from the McDonald asteroidal survey and that of faint ones from the Palomar-Leiden asteroidal survey are each individually consistent with the theoretical distribution, although they differ from each other by a numerical factor.
Remarks on the Size Distribution of Colliding and Fragmenting Particles
Authors: Bandermann Lothar W.
Published: July 2016

This paper is concerned with some aspects of determining the evolution of the size distribution of a finite number of mutually colliding and fragmenting particles such as the asteroids or interplanetary dust. If n(m, t) is the number of particles per unit volume per mass interval at time t, then n = dn/dt is the rate at which that number changes with time. This rate can be calculated if the laws are known according to which the colliding bodies erode one another and fragment and if the influence of collisions on the motion of the particles is known. To reduce the complexity of the problem, one assumes that the speed of approach between the bodies is always the same vcoll and that they, as well as the debris, occupy a fixed volume (“particles in a box”). Only collisions between two bodies are considered, and the way in which erosion and fragmentation occurs at a given value of vcoll depends only on their masses. The particles are assumed to be spherical.
The Profile of a Jetstream
Authors: Danielsson Lars
Published: July 2016

The Jetstream concept was introduced by Alfvén in 1969. Since then, the subject has been studied from various aspects by Danielsson (1969), Arnold (1969), Alfvén and Arrhenius (1970), Lindblad and Southworth, and Trulsen. In an attempt to define a Jetstream, we may say that it is a group of objects moving in space with almost identical orbits. The largest objects in the Jetstream may have any size, but the group must include a vast number of very small objects and their density must be large enough for the objects to interact. This means that collisions between the particles give rise to viscosity in the stream. Other interactions (e.g., by electromagnetic forces) are not excluded a priori.
Physical Properties of the Interplanetary Dust
Authors: Hanner Martha S.
Published: July 2016

The interplanetary dust may be composed of cometary material, interstellar grains, debris from asteroidal collisions, primordial material formed by direct condensation, or contributions from all of these sources. Before we can determine the origin of the dust, we need to know its physical nature, spatial distribution, and the dynamical forces that act on the particles. The spatial distribution and dynamics are separately treated in this symposium by Roosen. We discuss here the physical characteristics of the dust particles: their size distribution, chemical composition, physical structure, and optical properties.
On the Amount of Dust in the Asteroid Belt
Authors: Whipple Fred L.
Published: July 2016

Calculations of upper limits to the quantity of small particles in the asteroid belt are based on (1) the brightness of the counterglow coupled with observations and theory for the zodiacal cloud near Earth's orbit and (2) the destruction and erosion of asteroidal particles as they spiral toward the Sun because of solar radiation via the Poynting-Robertson effect. These calculations place the likely upper limit on asteroidal space particle density at the order of 5 to 10 times and the hazard to space vehicles at 2 to 4 times those near Earth's orbit. No such evidence indicates, however, that the hazard from small particles is actually much greater in the asteroid belt.
Structure of Comets and the Possible Origin of Faint Asteroids
Authors: Vanýsek V.
Published: July 2016

It is shown that very old and still active icy-conglomerate or “clathrate” cometary nuclei may exist at the outer boundary of the asteroidal belt and belong to the group of relatively stable “outer” short-period comets of which only a small fraction have been discovered or recognized as cometary objects.hich is much more convincing, it explains their brightness dependence on the heliocentric distance.

The search for these comets among very faint asteroids with the mean motion μ ≤ 600”, and the study of their behavior could be very important to our knowledge about the final stage of cometary nuclei.
Multiple Asteroid Flyby Missions
Authors: Brooks David R. , Hampshire William F.
Published: July 2016

The use of spacecraft for studying the physical properties of the asteroid belt can be approached in several ways. Certainly the simplest approach is to send a spacecraft into the asteroid belt and measure the effects of the environment encountered; this has the advantage of not requiring a vehicle to be targeted to any particular destination. With such an approach, properties may be obtained for those classes of objects that are populous enough to provide a significant number of encounters within the measurement range of the spacecraft. Unfortunately, the large asteroids do not constitute such a class of objects; the probability of an undirected spacecraft passing within measurement range of an asteroid having a diameter of 1 or more km is negligible.
Design and Science Instrumentation of an Unmanned Vehicle for Sample Return from the Asteroid Eros
Authors: Meissinger H. F. , Greenstadt E. W.
Published: July 2016

Unmanned missions to the asteroids have been proposed and investigated as part of the overall plan of exploration of the solar system. A principal incentive for landing on an asteroid and retrieving a surface sample for return to Earth is the expectation that detailed laboratory analysis of the sample material’s chemical composition, crystal structure, surface texture, magnetic characteristics, radioactive state, and age can provide essential clues, not available by other means, to the origin of asteroids and possibly the history and formative processes of the solar system (Alfvén and Arrhenius, 1910a,b; Bratenahl; Friedlander and Vickers, 1964; IIT Research Institute, 1964; Öhman, 1963). The results may indicate, for example, to what extent accretion or fragmentation processes have been involved in the formation of asteroids.
Precision of Ephemerides for Space Missions
Authors: Marsden B.G.
Published: July 2016

One of the most extensive programs of systematic observations of minor planets currently being conducted is that at the Crimean Astrophysical Observatory. The observed positions, together with the residuals from the predictions in the annual Ephemeris volumes, have been listed in the Minor Planet Circulars for several years now; and inspection of the residuals yields information about the accuracy of minor planet ephemerides as a whole.

The observations are made using a 40 cmf/4 double astrograph, the limiting magnitude being about 18. Between June 1968 and October 1969, corresponding to one synodic period of an average minor planet, about 40 percent of all the numbered objects were observed. These observations may be regarded as reasonably representative of all the planets. Observations were made of 60 of the objects with numbers in the 100’s and only 29 of those in the 1100’s, but in general the distribution was surprisingly uniform.
Laboratory Fundamental Data
Authors: Garton W. R. S.
Published: July 2016

An essential prescription for a review paper prepared for a conference is that it treat an area of currently flourishing research – a requirement directly conflicting with limitations of time and space. Under the present title, a large output of diverse and enterprising experimental endeavour has indeed appeared in the three years since the Maryland meeting, so that the reviewer is forced to be very selective. Fortunately, the situation is alleviated by the inclusion in Dr Burgess’s review of ‘Plasma Spectroscopy’ of much material describable as ‘fundamental data’ – such as f-value measurements obtained from plasma sources, shock-tubes and arcs. Again little reference is needed here to the important and extensive work on line identifications and classifications in spectra of medium to high ionization stages, since these will be covered by Dr C. Jordan’s review and several contributed papers.
Stark Broadening of UV Nickel Lines
Authors: Bengtson Roger D. , Miller Myron H. , Roig R. A.
Published: July 2016

Widths of Stark broadened Ni I Lines in the spectral range of 3000 Å–4000 Å have been measured using a gas driven shock tube as a spectroscopic source. Electron densities were determined using measured pressure and temperature data. Within the density range 6 × 1016 cm-3 to 12 × 1016 cm-3 the observed widths were linear functions of the electron density. There was no apparent correlation of observed widths with neutral density. Van der Walls broadening was presumed to be negligible because we observed narrow lines which should have had the same Van der Walls widths as computed with a classical theory as some of the wide lines we observed. In this way we were able to attribute almost all of the observed broadening to the Stark effect. The experimental results were compared with results of calculations of Stark broadening parameters using the program developed by Cooper and Oertel. The measured widths were about a factor three larger than the theoretical predictions. A part of this discrepancy is probably due to the fact that only LS allowed interactions were considered in the broadening calculations and possible incomplete classifications.