bluuebunny/crossref_metadata_2025 huggingface dataset:
The Determination of Stellar Turbulence by Low Resolution Techniques
Authors: Głębocki R. , Stawikowski A.
Published: July 2016

In this review the problem of measuring velocity field in stellar atmospheres from the observer’s point of view is presented. Our purpose here is to discuss observational methods in which detailed analysis of line profiles is not necessary, i.e. methods based on measurements of total absorption of lines (curve of growth and narrowband photometry), methods based on measurements of widths of lines (Goldberg-Unno method and curve of line width correlation) and measurements of differential line shifts. Therefore, our review will be limited to the discussion of basic assumptions of each method, to the analysis of their advantages and disadvantages, to a specification of a quantity which can be derived from a given method and finally to a brief presentation of the results. Usually, the low resolution methods provide an information about a particular component of the stellar velocity field. But the problem is more complicated as we do not know if particular components can be isolated from the stellar velocity field, thus, we do not know the real physical meaning of the measurable parameters. In this paper we shall adopt classical concept of micro- and macro-turbulence and convective type velocity. This simplified picture was criticized since 15 years on every colloquium devoted to hydrodynamic phenomena in the stellar atmospheres, but until now the theoreticians have not succeded in developing a theory which would satisfactorily interpret the observations.
Origin and Distributions of White Dwarfs
Authors: Weidemann W.
Published: July 2016

Today there is no doubt that white dwarfs represent the most common final stage of stellar evolution. Considerable progress has been made during the last decade in our understanding of their origin and distributions. This is reflected by the fact that it is now possible to predict – from basic theory of stellar evolution and stellar atmospheres – the existence of cooling degenerate stars with nearly the observed properties, i.e. a sequence of white dwarfs which fill in their majority a narrow strip in both two-color and color-magnitude diagrams. With other words: the empirically determined surface gravity and radius distributions – which correspond via the mass-radius relation to mass distributions – can now be basically understood within the currently adopted general scheme of stellar evolution with mass loss.
Nova Outburst Due to Accretion of H-Rich Matter onto White Dwarfs
Authors: Kutter G. Siegfried , Sparks Warren M.
Published: July 2016

We assume that the outburst of classical novae is the result of transfer of H-rich material from a red secondary star to a He or C/O white dwarf and the development of a thermonuclear runaway in the e-degenerate “base of the accreted H-rich envelope. Based on these assumptions, we have investigated this problem in several stages of increasing theoretical complexity and physical realism.
Historical Records of ZZ Ceti Variables
Authors: Liller Martha H. , Hesser James E.
Published: July 2016

As a consequence of the discovery of the high-frequency variations that define the ZZ Ceti class of variables, observations of them or of new candidates have naturally tended to sample preferentially the period range from 1 or 2 seconds to ~ 30 minutes in unfiltered light. Hence, little is known about variability on time scales > 30 minutes, with the possible exception of some curiosities in the high-frequency literature and in Eggen’s monumental photoelectric UBV observations; a brief summary of some potentially disquieting cases has been given recently by Hesser, Lasker and Neupert (1979). Inasmuch as the existence of unexplained observational discrepancies still admit the possibility that the high-frequency variations may be but one manifestation of the type or time scales of white-dwarf variability, we have measured several ZZ Ceti variables by iris photometry and by visual estimates on the plates of the Harvard collection. Based on an average of 50 observations per star over 55 years, going back to the 1890’s, we find no positive indications of variations in excess of +0.10–0.15 mag for any of the following stars:
The Orbital Period of G61-29
Authors: Nather R. E. , Robinson E. L. , Stover R. J.
Published: July 2016

The proper-motion star G61-29 (Giclas et al 1971) was discovered to have an emission-line spectrum consisting entirely of helium by Burbidge and Strittmatter (1971), who noted that the very broad lines (ca. 32 Å at λ4471) seemed to have variable profiles. Warner (1972) suggested that the star might be a close binary system, with the emission lines arising from an accretion disk surrounding a white dwarf, and searched for evidence of binary motion using high speed photometry. He suggested a tentative orbital period of 6h 16m, which subsequent observations were unable to confirm. Smak (1975) studied the star spectroscopically and agreed with Warner’s accretion disk hypothesis based on his analysis of the emission line profiles, but was also unable to derive evidence of orbital motion from his spectra, which were exposed for about 40 minutes each. Greenstein et al.(1977) also observed profile variations in spectra with shorter exposures, but evidently did not search for periodicities.
Problems in Common Envelope Evolution as a Pre-Stage of Cataclysmic Variables
Authors: Meyer F. , Meyer-Hofmeister E.
Published: July 2016

We follow the evolution of an originally widely separated red-giant in orbit with a low mass main sequence star to a cataclysmic binary system. Angular momentum transport via differential rotation leads to a common envelope around the red giant core and the main sequence star. The internal binary separation shrinks by frictional transfer of angular momentum to the extended red giant envelope. This shrinkage continues at nearly constant luminosity until after several hundred years the binary “Roche lobe” cuts into the dense layers of the main sequence star. The envelope will then be lost by a thermal instability. Method and computations for a 5 M⊙ + 1 M⊙ binary are presented elsewhere (Astron. Astrophys. 1979, in press).
The Status of the Dirbe Instrument on the COBE
Authors: Hauser M.G. , Kelsall T. , Moseley H. , Silverberg R. , Murdock T.L. , Mather J.C. , Smoot G. , Weiss R. , Wright E.L.
Published: July 2016

The Diffuse Infrared-Background Experiment (DIRBE) on the Cosmic Background Explorer (COBE) satellite is a 10-band absolute photometer covering the wavelengths 1–300 microns using photovoltaic, photoconductive, and bolometric detectors. The input is via a 19-cm, off-axis, highly-baffled Gregorian telescope, with the detectors located at a pupil plane so they share the same field of view (0.7 × 0.7 degrees). The whole assembly is mounted inside a 1.4 K; super-fluid, liquid-He dewar, which is shared with the Far Infrared Absolute Spectrometer (FIRAS) instrument. Each day half of the sky is surveyed, as the line-of-sight of the DIRBE is canted 30 degrees to the COBE spin axis. The whole sky is fully observed in 6 months, as the spin axis precesses at about 1 degree per day. At present each sky pixel has been observed at least once. The basic findings on the general brightness of the sky - Zodiacal light and galaxy - are provided, as well as a synopsis of the advantages and disadvantages associated with a space-borne observatory. The relationship of our experience and findings with respect to possible future missions and their scientific goals is presented.
The Space Infrared Telescope Facility (SIRTF)
Authors: Fazio Giovanni G. , Eisenhardt Peter
Published: July 2016

The Space Infrared Telescope Facility (SIRTF) is a one-meter class observatory for infrared astronomy that will be launched into high earth orbit by NASA in the late 1990’s. SIRTF’s three focal plane instruments will permit imaging and spectroscopy over most of the infrared spectrum with sensitivities of 100 to 10,000 times their predecessors. This paper briefly reviews SIRTF’s capabilities, science objectives, and current status.
A Submillimeter Mission for the 1990s: SMMM
Authors: Phillips T.G.
Published: July 2016

Submillimeter wavelengths hold the key to some of the most important aspects of astronomy. These range from star-forming molecular clouds and proto-planetary disks in our galaxy to infrared emitting galaxies at cosmological distances. Indeed, the essential problems of star-formation and galaxy-formation will be directly probed by the submillimeter spectral lines and continuum radiation emitted by these objects. Other fascinating topics falling into the submillimeter band include the Wien component of the cosmic background radiation, containing information on the nature of the early universe, and nearer to home, the spectroscopy of planetary atmospheres. Since the submillimeter contains fundamental information on the physics and chemistry of so many aspects of our universe, every effort should be made to provide the very best instrumentation for these astronomical studies. We should be capable of detection and analysis of even the most distant objects yet conceived.

Telescopes specifically designed for submillimeter astronomy are now operating on high mountain sites and the field is developing in an exciting and rapid fashion. NASA’s airborne program has been in operation for some time and has been of the greatest importance in getting the field started. Both ground and airborne programs will continue to be essential because of their flexibility for implementing new investigations, for instrument development and to support the growth of an active science community, especially students. However, it is now essential to move forward on a space program.
International VLBI Satellite (IVS)
Authors: Schilizzi R. T.
Published: July 2016

IVS is under study in ESA as a second generation space VLBI observatory. The mission concept calls for a 25 m diameter radio telescope in space funded by the principal space agencies. Orbiting the Earth and observing in concert with the established ground-based VLBI arrays in Europe, USA, USSR and Australia, IVS will provide high quality images of galactic and extragalactic radio sources at wavelengths spanning the radio band from decimetres to millimetres with resolution as high as 10 micro arcseconds and sensitivity equal to those of ground-based images. New features of IVS compared to the first generation missions are: a more than order of magnitude increase in sensitivity; an order of magnitude increase in maximum angular resolution; extension of the wavelength range to the millimetre band; and the capability to operate as a stand-alone radio telescope enabling it to explore new frontiers in spectral line and microwave background research, in particular the distribution of galactic molecular oxygen and Compton scattering of the microwave background by foreground cluster gas.
The Ultraviolet Imaging Telescope for Astro 1
Authors: Stecher T.P.
Published: July 2016

The Ultraviolet Imaging Telescope (UIT) is a 38-cm Ritchey-Chretien telescope with 2 arc-sec resolution and a 40 arc-min field of view. There are two magnetically-focused image intensifiers which record on film. One has a Cs-I photocathode and 6 filters, the other has a Cs-Te cathode with 5 filters and an objective grating. The film transports contain 1000 frames each of IIa-O film. The point source threshold is m (2200 Å) = 22.0 in a 30 min integration through the widest filter. For extended sources the corresponding mag is 26.0/sq. arc-sec. The UIT complements the instruments on the Hubble Space Telescope in that its field of view is ~ 200 times that of the Wide Field Camera, it has extremely good visible light rejection and is more sensitive to diffuse structures in the UV. The UIT is well-suited to locating interesting UV targets for HST follow-up and the study of large regions such as nearby galaxies and clusters.

Astro 1 will point the co-aligned UV instruments at ~ 200 targets during its 10 day mission. The UIT science team’s primary scientific programs include: The search and survey of the UV sky; SN1987A for the UV light echo; The helium burning and collapsing degenerate stars in star clusters; The structure of highly ionized regions in planetary nebulae and supernova remnants; The physics of massive star formation in spiral structure of galaxies; The interstellar medium of other galaxies; A search for active nuclei in ‘ normal ’ galaxies; The very faint regions surrounding galaxies that are produced by interactions, mergers, ejection, or accretion flows; The study of stellar populations of galaxies and galactic evolution, ages and chemical content of galaxies, and the study of large samples of galaxies in nearby clusters for comparison with objects at large lookback times.
Science Operations for Future Space Astrophysics Missions
Authors: Riegler Guenter R.
Published: July 2016

Plans for astrophysics science operations during the decade of the nineties are described from the point of view of a scientist who wishes to make a space-borne astronomical observation or to use archival astronomical data. In the process of preparing a proposal, making an observation, and carrying out data processing, analysis, and dissemination of results, the scientist will be able to use a variety of services and infrastructure, including the “Astrophysics Data System”. The current status and plans for these science operations services are described.
United States Launch Vehicle Systems
Authors: Krause Robert B.
Published: July 2016

United States policy for national space launch capability provides for a balanced mix of launches, utilizing the Space Shuttle and Expendable Launch Vehicles (ELVs). It also directs government agencies to encourage and support the development of a domestic commercial expendable launch vehicle industry. This is to be accomplished by contracting for necessary ELV launch services directly from the private sector and by facilitating access by commercial launch firms to national launch and launch-related property and services they request to support these commercial operations.

The current mixed fleet includes the Space Shuttle and four expendable launch vehicles - Titan, Atlas, Delta and Scout. New small class launch vehicles, including Pegasus, are in development. In addition, studies are underway to assure that the United States has cost-effective, reliable access to space, heavy-lift launch capability, and a new manned spacecraft after the current Space Shuttle reaches the end of its operational life. This paper will highlight the current capabilities of the mixed fleet and summarize the plans for new or modified United States launch vehicles through the first decade of the next century.
ESA’S Space Transportation Programme
Authors: Feustel-Buechel J. , Wamsteker W.
Published: July 2016

The overall development of ESA’s Space Transportation Programme can be perceived in two major phases. The first phase finished with the transfer of the ARIANE 1-4 launch systems to Arianespace for utilisation and commercialization. The second phase was started after the success of the ARIANE launcher programme had created a sound basis for Europe’s space industry in the evolving commercial space transportation market. This has lead to the definition of a second phase of the launcher development program which is expected to fulfil the needs for transport into space for many years to come. The wide objectives of the program makes it not only suitable for commercial applications but can also be expected to cover the launching needs for future Space Astrophysics missions.

Market studies of the future commercial space transportation needs show growing satellite masses and an increased worldwide competition. Europe therefore needs a powerful launcher with improved cost-effectiveness and improved reliability for geostationary missions. On the other hand the discussion about the optimum launcher, spacecraft size and orbits for Astronomy missions, as well as for Space Science missions in general, is still a matter under debate, as explained by Dyson elsewhere in these Proceedings. The experience obtained with IUE and EXOSAT-Observatory satellites which, due to their general user nature, do not have a rigidly preplanned observing program - seem to suggest that, at least for operational motives, high orbits appear preferable for such satellites. This is especially true as compared to the operational and planning difficulties foreseen with the recently launched Hubble Space Telescope, which is in low earth orbit (LEO). Of course, for firmly pre-scheduled observatories with a predetermined Science program, such as COBE and HIPPARCOS, this choice may not be obvious.
Lunar-Based Astronomy
Authors: Smith Harlan J.
Published: July 2016

The Moon offers for astronomy a truly impressive array of advantages, many of which are briefly reviewed in this paper. These advantages include especially the vast inertial platform and the expected availability of human and robotic “hands-on” installation, maintenance, and modification. The Earth-orbiting Great Observatories will advance our knowledge to a new plateau, but some of the most fundamental observational questions which we are already asking will require lunar-based instruments, including very large filled-aperture telescopes, interferometers with baselines of tens and ultimately hundreds of kilometers, and the utilization of the radio-quiet backside. It is already time to begin planning the first such installations.
The Astrophysics of the Future
Authors: Longair M.S.
Published: July 2016

It is with some trepidation that I set down these thoughts. The history of physics and astronomy is littered with pontifications about the future, most of which simply end up embarrassing their authors. There are many projects which can be regarded as very safe bets but these might not be the ones which totally transform the nature of the discipline. The situation is analogous to that in the early 1950s when extragalactic astronomy simply meant optical astronomy since there was no other way of carrying out such studies – few would regard that as an adequate position nowadays. Similarly, it is difficult nowadays to imagine cosmology without the Microwave Background Radiation. Thus, the problem for the prognosticator is to tread the narrow line between science fiction and a simple extrapolation of what we do now with our facilities. It is in the spirit of this meeting to concentrate upon space observatories but I believe that it is instructive to look at the whole of astronomy, both from space and from the ground.
A Low Energy Gas Scintillation Proportional Counter for the SAX-X-Ray Astronomy Satellite
Authors: Parmar A.N. , Smith A. , Bavdaz M.
Published: July 2016

The payload of the italian/Dutch satellite SAX will include a set of four concentrators each with a geometric area of 90 cm2. Imaging GSPCs will be located at the focal planes of the concetrators. The Space Science Department of ESA will provide one of these GSPCs which will be sensitive to X-rays with energies between 0.1-10 keV. In order to achieve such a low-energy energy response, a driftless configuration and a thin plastic window have been adopted. At 6 keV the collecting area will be 50 cm2 and the energy and angular resolutions 8% and 1.6′ FWHM, respectively.
The Exosat Results Database
Authors: Parmar A.N. , White N.E.
Published: July 2016

The EXOSAT database provides on-line access to the results and data products (spectra, images and lightcurves) from the EXOSAT mission as well as EINSTEIN SSS and MPC spectra, EINSTEIN HRI images and IUE spectra of X-ray sources. In addition, a number of well-known optical, infrared, and X-ray catalogs, including the HST guide star catalog are available. The complete database is located at the EXOSAT observatory at ESTEC in the Netherlands and is accessible remotely via SPAn by typing ‘set host 28703’ and logging in to account ‘XRAY’. Alternatively, a sub-set of the database is available at GSFC and may be accessed by typing ‘set host 6467’. Access is also possible via Arpanet/Internet, GTE TELENET and by direct mail.

The database management system has been specifically developed to efficiently access the database and to allow the user to perform statistical studies on large samples of astronomical objects as well as to retrieve information on single sources. The system has been written to be mission independent and includes timing, image processing and spectral analysis package as well as software to allow the easy transfer of analysis results and products to the user’s own institute.

Further information about the system including user’s guides is available from A.N. Parmar and N.E. White at ESTEC and from their colleagues J. Behnke/Code 634 and K. Arnaud/Code 666 at GSFC.
The Stability of the Planetary Triangular Lagrange Points
Authors: Mikkola Seppo , Innanen K.A.
Published: July 2016

Numerical, self-consistent, n-body integrations of the solar system show significant indications of medium-term (i.e. several million-year) stability for the various planet-Sun L4,L5 configurations. A progress report of our computations, emphasizing the inner solar system, will be given. There exist interesting possibilities for these locations (including the Earth) as the sites for longer term scientific applications, both pure and applied.
Particle Acceleration Mechanisms
Authors: Blandford R. D.
Published: July 2016

High-energy particle acceleration is observed to proceed in a diverse variety of astrophysical sites ranging from the terrestrial aurorae to the most distant quasars. Particle acceleration is a fairly common channel for the release of large-scale kinetic, rotational, and magnetic energy. Physical mechanisms include electrostatic acceleration, stochastic processes and diffusive shock energization. Cosmic-ray energy spectra have shapes which reflect escape, collisional, and radiative losses. The overall acceleration efficiency is controlled by the low-energy particle injection which may, in turn, feed back into the energization. Recent observational developments, which illustrate these general principles and raise fresh questions, are briefly summarized.

Subject heading: acceleration of particles
Sources and Acceleration of Energetic Particles in Planetary Magnetospheres
Authors: Möbius Eberhard
Published: July 2016

Energetic particles in the magnetospheres of the solar system originate from various different sources, such as the solar wind, the planetary ionospheres as well as the moons and rings of the planetary systems. Important acceleration sites are the auroral regions, the magnetotail, and the equatorial regions of the magnetospheres where electric fields, wave-particle interactions and magnetic pumping are among the major acceleration mechanisms proposed. Over the last decade mass- and charge-sensitive particle spectrometers on satellites and space probes have collected a wealth of information about the relative contribution of the various particle sources and the major acceleration processes to the energetic particle populations. Emphasis will be put on recent studies of the source populations and the acceleration processes in the Earth’s auroral zones and magnetotail. Furthermore, the Jovian system with the largest magnetosphere and its unique mixture of particle sources with strong contributions from moons will be highlighted in some results fromUlysses.

Subject headings:acceleration of particles — planets and satellites: general
Rosat Observations of Stellar Flares
Authors: Schmitt J. H. M. M.
Published: July 2016

X-ray observations of stellar flares obtained during the ROSAT all-sky survey as well as in the ROSAT pointing program are discussed. The ROSAT all-sky survey allowed—for the first time—an unbiased search for stellar flares among all types of stars. A fundamentally new result obtained is that flares can occur on all types of late-type stars, thus supporting the view that the X-ray emission from these stars is controlled by magnetic processes. Long-duration flares can be studied with the all-sky survey data particularly well, and an especially well-observed long-duration flare event on the flare star EV Lacertae is presented and discussed in detail. Finally, the issue of time variability on the shortest detectable timescales and the question of microflaring is discussed using ROSAT data from a pointed observation of UV Ceti.

Subject headings: stars: coronae — stars: flare — stars: late-type — X-rays: stars
Gamma-Ray Observations of Pulsars
Authors: Ulmer M. P.
Published: July 2016

We report on Compton Gamma Ray Observatory observations of six detected pulsars: the Crab, Vela, Geminga, PSR B1509-58, PSR B1706-44, and PSR B1055-52. We combine these data with radio data and X-ray data to provide an overview of what is known about gamma-ray pulsars. We discuss light curves, spectra, and radio/gamma-ray phase offsets, and present several tentative patterns in the data. These include constant phase with γ-ray energy; a correlation between gamma-ray and X-ray luminosity; an anticorrelation between the gamma-ray luminosity and the efficiency in converting rotational energy loss into gamma-ray flux; and a correlation between the pulsar period and radio/gamma-ray phase offset. We also suggest that the emission models that have been proposed to date cannot explain the similarities of the average gamma-ray light curves observed over a wide range of energies. Further, unless a narrow beam is assumed, pulsars such as PSR B1055-52 and Geminga appear to be radiating a significant fraction of their rotational energy loss in the form of gamma rays.

Subject headings: gamma rays: observations — pulsars: general — radio continuum: stars — X-rays: stars
Observational Features of Cosmic Gamma-Ray Bursts: Evidence for Galactic Versus Extragalactic Origin
Authors: Hurley Kevin
Published: July 2016

The recent observational data on gamma-ray bursts are reviewed. Burst time histories display features at the millisecond level which suggest a compact object origin. Lines in the energy spectra and spectral evolution point toward a Galactic neutron star origin, even though line features have not yet been confirmed in recent data. The Galactic distribution of burst sources, however, is both isotropic and sampled to its characteristic distance, making it unlikely that the sources are related to populations of Galactic neutrons stars we are familiar with. Counterpart searches, previously carried out years after the gamma-ray bursts, are now proceeding days after the events. Based on the current data, it is impossible to conclude whether bursters are Galactic, extragalactic, or both. Data being returned from current experiments, as well as data from new experiments to be launched in the next few years, may yet provide the answer.

Subject heading: gamma rays: bursts
The Status of Ultra-High-Energy Gamma-Ray Observations
Authors: Protheroe R. J.
Published: July 2016

In 1983 Samorski and Stamm found evidence of ultra-high-energy (UHE) gamma-ray emission from Cygnus X-3 in archival data from the Kiel air shower array. The emission appeared to be emitted only at one phase in the binary orbit. The Kiel array was sensitive to air showers generated by particles with energies above 3 × 1015 eV. Their discovery led to searches in archival data from other arrays for evidence of UHE emission from Cygnus X-3 and other potential sources in the Galaxy, and to the construction of new air shower arrays dedicated to UHE astronomy.

In the mid 1980s many groups around the world claimed detections of Cygnus X-3, Hercules X-1, Vela X-1, and other objects. Cygnus X-3 is strongly variable at all wavelengths, and so it would be surprising if this variability did not extend to UHE gamma-rays also. This indeed appeared to be the case, and in the mid to late 1980s the UHE gamma-ray output showed a steady decline apart from transient UHE emission following giant radio flares. With the exception of possible detections above 1017 eV by the Fly’s Eye and Akeno Array, I am unaware of any statistically compelling claimed detections of this source reported over the past 4 years. The new arrays—CASA-MIA and SPASE—have not detected any of the claimed sources, and it seems likely that at least some of these early claims may have been premature. However, although none of the observations taken alone was of extremely high statistical significance, the observations of Cygnus X-3 by different groups showed a consistency which I feel cannot be ascribed to chance alone. The observations of Cygnus X-3 and the Crab Nebula/Pulsar are reviewed with particular reference to the results published during the last 5 years.

Subject headings: gamma rays: observations — pulsars: individual (Crab Nebula) — stars: individual (Cygnus X-3)
Monitoring Variability of the Sky
Authors: Paczyński Bohdan
Published: July 2016

Variability in the sky has been known for centuries, even millennia, but our knowledge of it is very incomplete even at the bright end. Current technology makes it possible to built small, robotic optical instruments, to record images and to process data in real time, and to archive them on-line, all at a low cost. In addition to obtaining complete catalogs of all kinds of variable objects, spectacular discoveries can be made, like the optical flash associated with GRB 990123 and a planetary transit in front of HD 209458. While prototypes of parts of such robotic instruments have been in operation for several years, it is not possible to purchase a complete system at this time. I expect (hope) that complete systems will become available ‘off the shelf’ in the near future, as monitoring bright sky for variability has a great scientific, educational and public outreach potential.
MOA Extra-Solar Planet Research via Cluster Supercomputing
Authors: Rattenbury Nicholas , Bond Ian , Yock Phil , Skuljan Jovan
Published: July 2016

Developments in the search for extra-solar planets via gravitational microlensing by the Japan/New Zealand group MOA are discussed. The use of the Kaláka cluster computer is introduced and preliminary results presented.
The 1.3-meter Robotically Controlled Telescope: Developing a Fully Autonomous Observatory
Authors: Gelderman Richard
Published: July 2016

The former KPNO 1.3-meter telescope is being refurbished and automated by a consortium of U.S. institutions, headed by Western Kentucky University, with the goal of a 2002 recommissioning as the Robotically Controlled Telescope (RCT). The 1.3-meter RCT will operate in fully autonomous mode to obtain guided images for a variety of research and education programs. Distinctions between a fully autonomous versus robotic observatory are presented, along with a discussion of why fully autonomous operation is necessary for increased productivity of small telescopes.
The Development of Advanced-Technology Automated/Robotic Telescope Systems and the Future of Small-Telescope Astronomy
Authors: Williams Richard J. , Mulherin James
Published: July 2016

During the 1990s groups at universities around the world developed small working automated/robotic telescopes that proved the feasibility of using such systems for education and research projects. A few of the more successful projects such as the Bradford Robotic Observatory in the United Kingdom and the University of Iowa’s Automated Telescope Facility (AFT) and Iowa Robotic Observatory (IRO) programs proved how useful and powerful these systems can be in practice. This paper describes how one company, Torus Technologies, developed hardware and software technologies to create the most advanced integrated small automated/robotic telescope systems in the world. These systems were designed from the “bottom up” to be automated/robotic telescopes capable of operating an entire observatory including domes, CCD cameras, and other peripheral equipment.

Automated/robotic telescopes can play a major role in enabling small colleges and universities, especially in developing countries, to actively participate in serious “hands on” research and education projects that otherwise would not be practical. A commercially available affordable, high-precision, and proven turnkey automated/robotic small telescope system capable of operating remotely via the Internet is crucial for bringing this technology into widespread use. Today Torus Technologies telescopes are installed at locations worldwide as primary instruments for research programs, discovery and monitoring programs, and education programs. This paper describes some of the current applications for using these telescopes and how these telescope systems will be used in the future in standalone installations and in global networks.
Design of a Multi-CCD Controller
Authors: Kang Yong-Woo , Byun Yong-Ik , Yu Sung-Yeol , Park Sun-Youp , Park Yeo-Jin
Published: July 2016

We are developing a robust Multi-CCD control system for wide-field surveys of various kinds. Our design concept and possible application modes are introduced.
The Lick Observatory Supernova Search with the Katzman Automatic Imaging Telescope
Authors: Filippenko Alexei V. , Li W. D. , Treffers R. R. , Modjaz Maryam
Published: July 2016

The Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory is a fully robotic 0.76-m reflector equipped with a CCD imaging camera. Its telescope control system checks the weather, opens the dome, points to the desired objects, finds and acquires guide stars, exposes, stores the data, and manipulates the data without human intervention. There is a 20-slot filter wheel, including UBV RI. Five-minute guided exposures yield detections of stars at R ≈ 20 mag when the seeing is good (≤2″).

One of our main goals is to discover nearby supernovae (SNe; redshifts generally less than 5000 km s−1), to be used for a variety of studies. Special emphasis is placed on finding them well before maximum brightness. A limit of ~ 19 mag is reached in the 25-sec unfiltered, unguided exposures of our Lick Observatory Supernova Search (LOSS). We can observe over 1200 galaxies in a long night, and we try to cycle back to the same galaxies after 3 to 4 nights. Our software automatically subtracts template images from new observations and identifies supernova candidates that are subsequently examined by student research assistants. LOSS found 20 SNe in 1998, 40 in 1999, and 36 in 2000, making KAIT the world’s most successful search engine for nearby SNe. We also find novae in the Local Group, comets, asteroids, and cataclysmic variables. Multifilter follow-up photometry is conducted of the most important SNe, and all objects are monitored in unfiltered mode. A Web page describing LOSS is at http://astro.berkeley.edu/~bait/kait.html.
Optical Identification of Gamma-Ray Bursts at Kenting Observatory
Authors: Sun Wei-Hsin , Tseng Shun-Tang
Published: July 2016

A remotely-controlled observing station, the Kenting Observatory, has been established in the Kenting National Park, at the southern tip of Taiwan. There are four observing systems at the Observatory: (1) a Meade 16-inch reflector with an SBIG spectrograph plus an SBIG STV; (2) an RC-16inch reflector with an FLI CCD; (3) a Celestron 14-inch with an ST-7E CCD; and (4) a Binocular system of two Canon F1.8 telephoto lens with two FLI CCDs. One of the scientific tasks of this observatory is to provide fast response to satellite alerts in the hopes of identifying the optical counterparts of Gamma-Ray Bursts (GRBs) via the global effort of GRB Coordinated Network (GCN). In this conference proceedings, we describe the instruments and the science projects being carried out in the Observatory.
Observations of Variable Stars by the 76-cm SuperLight Telescope of NCU
Authors: Li J.Z. , Wu C.H. , Zhang Z.W. , Chang C.P. , Lin C.Y. , Li H.H. , Tsay W.H. , Ip W.H. , Chen W.P.
Published: July 2016

The self-constructed Super-Light telescope of the National Central University is now ready for open use. Systematic studies of RR Lyraes stars and other variables are outlined and some preliminary results are introduced.
The Role of Small Telescopes in the Discovery and Follow-up of Near Earth Objects
Authors: Boattini Andrea
Published: July 2016

The discovered population of Near Earth Objects (asteroids and comets) consists of more than 1,300 bodies. Small telescopes provided with a large field of view have played a major role in the field, contributing to the discovery of about 95% of the total known population. We present a brief summary of the steps that have led to the present knowledge and suggestions to improve it. A proposal for accessing archival images to search for previous apparitions is presented.
Concluding Remarks
Authors: Warner Brian
Published: July 2016

This is the first IAU conference devoted to research with small telescopes since the Symposium on Instrumentation & Research Programs for Small Telescopes, held in Christchurch, New Zealand, almost exactly fifteen years ago. Both the climate for, and the definition of, small telescopes has changed since then. Now, with the construction and operation of 8m class telescopes, anything less than about 3m is considered small. But whereas fifteen years ago there were concerns whether instrumentation could be improved in order to make small telescopes competitive, and whether there was any ultimate future for these outside of education, it is now clear that an extensive niche has been found, with remodelling, refurbishment and construction of new small telescopes well under way.
The Confrontation of Mean-Field Theories with Numerical Simulations
Authors: Krause Fritz
Published: July 2016

The investigation of magnetic phenomena on the Sun is confronted with the problem of turbulently moving electrically conducting media in rotating objects. One way of attacking this complicated problem, which was at first successful, was the development of mean-field magnetohydrodynamics, where the cooperative action of the small-scale turbulence was taken into account by certain average effects. The development of more and more powerful computers now offers possibilities of calculating the small-scale phenomena in a direct way. This paper is an attempt to compare these approaches, at least as far as there are comparable results.
Convective Overshoot as a Source of Helicity
Authors: Jennings R. L.
Published: July 2016

In order to understand what happens in the Sun when convection overshoots into the radiation zone an idealized model of penetrative convection with rotation is studied. Here we highlight two properties of the model which occur with parameters relevant to the Sun. Firstly rotation allows motions to persist far beneath the convection zone, and secondly the profile of helicity with depth is dominated by a local maxima just beneath the convection zone. This second result has consequences in dynamo theory.
Diffusion of Particles, Heat and Magnetic Fields in Compressible Turbulent Media
Authors: Dolginov A.Z. , Silant’ev N.A.
Published: July 2016

A new method for the calculation of kinetic coefficients is presented. This method allows us to obtain the distribution of scalar and vector fields (such as the temperature, the admixture particle number density and the magnetic field) in turbulent cosmic media with any value of S = u0т0/R0. The explicit expression for the “turbulent” diffusivity DT is obtained. In some cases DT becomes negative, implying the clustering of the admixture particles in patches (a local increase of the temperature and magnetic fields). The magnetic α-effect is considered for the case S ~ 1.
The Role of Overshoot in Solar Activity: A Direct Simulation of the Dynamo
Authors: Brandenburg A. , Jennings R.L. , Nordlund Å. , Stein R.F. , Tuominen I.
Published: July 2016

We investigate convective overshoot in a layer of electrically conducting fluid. The radiative conductivity is assumed to be larger in the lower part of the layer which makes it stable to convective motions, yet penetrative convection from the upper layer can occur. The numerical resolution is 633 gridpoints. We observe a dynamo effect for magnetic Reynolds numbers around one thousand when a magnetic seed field is rapidly concentrated to form flux tubes. Later the average magnetic field is expelled from the convectively unstable regions, but it accumulates in the interface between the convection zone and the radiative interior.
Fractal Flux Tubes of the Solar Magnetic Field
Authors: Ruzmaikin Alexander , Sokoloff Dmitry , Tarbell Theodore
Published: July 2016

The small-scale solar magnetic field exceeding a given threshold forms a fractal set. A dimension of this fractal is found from magnetograms with varying linear resolution. The dimension depends on the value of the threshold magnetic field (multifractality). A simple dynamo model explaining the origin of the fractal magnetic structure is considered. The dynamo produces a magnetic field in the form of flux tubes with a fractal distribution of magnetic field across the tube. The observed dimension gives a possibility of estimating a degree of structuredness of the solar velocity field.
Learning about Stellar Dynamos from Long–term Photometry of Starspots
Authors: Hall Douglas S.
Published: July 2016

Spottedness, as evidenced by photometric variability in 277 late-type binary and single stars, is found to occur when the Rossby number is less than about 2/3. This holds true when the convective turnover time versusB–Vrelation of Gilliland is used for dwarfs and also for subgiants and giants if their turnover times are twice and four times longer, respectively, than for dwarfs. Differential rotation is found correlated with rotation period (rapidly rotating stars approaching solid-body rotation) and also with lobe-filling factor (the differential rotation coefficientkis 2.5 times larger forF= 0 thanF= 1). Also reviewed are latitude extent of spottedness, latitude drift during a solar-type cycle, sector structure and preferential longitudes, starspot lifetimes, and the many observational manifestations of magnetic cycles.
Limits on the Magnetic Flux of a Pre-Main Sequence Star
Authors: Basri G. , Marcy G.W.
Published: July 2016

We attempt to detect a magnetic field on the weak T Tauri star, TAP35, via the enhanced equivalent widths of Zeeman-broadened absorption lines. We synthesize 25 Fe I lines, having a range of Zeeman sensitivities, using an LTE Stokes line-transfer calculation. The oscillator strengths of all lines are empirically determined a priori using the same line-transfer code applied to the spectrum of the magnetically quiet star, τ Ceti. The Fe abundance of TAP35 was established by synthesizing lines that are insensitive to Zeeman splitting. We find that the equivalent widths, Weq, of Zeeman-sensitive lines in TAP35 are systematically enhanced relative to the Zeeman-insensitive lines, consistent with the presence of widespread, kilogauss fields. The excess Weq can be explained by a product of field strength and surface filling factor (Bf) of 1 kiloGauss. A strong upper limit can be placed on the product of those two quantities, Bf < 2 kG. This measurement bears on the physics of T Tauri coronae, chromospheres, dynamos, and accretion-disk boundary layers.
Nuclear Processes Related to the Ap Stars and the Heaviest Chemical Elements
Authors: Kuchowicz B.
Published: July 2016

Isotopic shifts in the lines of the heavy elements in Ap stars, and the characteristic abundance pattern of these elements point to the fact that we are observing mainly the products of rapid neutron capture. The peculiar A stars may be treated as the show windows for the products of a recent r-process in their neighbourhood. This process can be located either in Supernovae exploding in a binary system in which the present Ap stars were secondaries, or in Supernovae exploding in young clusters. Secondary processes, e.g. spontaneous fission or nuclear reactions with highly abundant fission products, may occur further with the r-processed material in the surface of the Ap stars. The role of these stars to the theory of nucleosynthesis and to nuclear physics is emphasized.
Loss of Angular Momentum in Magnetic Ap Stars
Authors: Wolff Sidney C.
Published: July 2016

Some of the most important questions about the Ap stars that remain unanswered concern the origin and evolution of these objects. Different authors have suggested that the Ap stars occupy a variety of evolutionary states, from pre-main sequence to post-red giant phases of evolution. I would like to describe briefly some evidence that indicates that the magnetic Ap stars are main sequence objects, an idea that has been generally accepted for some time, and that angular momentum is lost as these stars evolve away from the zero-age main sequence.
Peculiarity Parameters
Authors: Maitzen H. M.
Published: July 2016

Ap stars are peculiar in many aspects. During this century astronomers have been trying to collect data about these and have found a confusing variety of peculiar behaviour even from star to star that Struve stated in 1942 that at least we know that these phenomena are not supernatural. A real push to start deeper theoretical work on Ap stars was given by an additional observational evidence, namely the discovery of magnetic fields on these stars by Babcock (1947). This originated the concept that magnetic fields are the cause for spectroscopic and photometric peculiarities. Great leaps for the astronomical mankind were the Oblique Rotator model by Stibbs (1950) and Deutsch (1954), which by the way provided mathematical tools for the later handling pulsar geometries, anti the discovery of phase coincidence of the extrema of magnetic field, spectrum and photometric variations (e.g. Jarzebowski, 1960).
Element Identifications in Chemically Peculiar Stars of the Upper Main Sequence
Authors: Cowley Charles R.
Published: July 2016

The element identification procedures introduced by Hartoog et al. (1973) have now been applied to some 55 stars including 9 “normal” stars. We have searched for 92 elements, usually in two stages of ionization using, almost exclusively 2.4 Å/mm plates. The results that we wish to report are summarized below:

1.

A search for ten actinides, using some unpublished material generously provided by Drs. Worden, Fred and Crosswhite was entirely negative. Only uranium and probably thorium in HR 465 at rare earth (RE) maximum have statistical support for their presence, although uranium may be present in other stars.

2.

We have found no credible evidence for any rare earth in any manganese star. This is a rather basic difference between the spectra of the manganese stars and the Am stars. Calculations show that the rare earth abundances could be rather similar in the Am and Mn stars.

3.

We confirm the result of Jones, Wolff and Bonsack (1974), that Ho is present in HD 51418. HR 465, (at RE max) is the only other star for which we have statistical support for a Ho identification. We have not analyzed HD 101065. The heaviest lanthanide that we have identified is Er, again in HR 465 at RE maximum.

4.

Spectral similarities of some of the cool magnetic Ap stars and certain Am stars are remarkable, and deserve more consideration. For example, 32 Aqr an extreme Am, has about the same Strömgren 4-colors as γ Equ. With the exception of Call, the line spectra of the two stars are extraordinarily alike, and make it difficult to believe that the two objects are unrelated.

5.

We have published (or have in press) an examination of the odd - Z anomalies which appear in the manganese stars at P, Ga, and Y. These peculiarities are extremely difficult to explain with conventional nucleosynthesis. However, we note that slow rotation alone does not appear capable of producing the anomalies.

6.

The abundance variations among the lanthanides among the magnetic Ap stars are large and definite.

The rich variety in the abundance patterns that we have observed is not readily accounted for by any of the current theories of Ap star abundances.