bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrodynamics of Disk-Accreting Magnetic Neutron Stars
Authors: Miller M. Coleman , Lamb Frederick K. , Hamilton Russell J.
Published: July 2016

We have investigated the electrodynamics of magnetic neutron stars accreting from Keplerian disks and the implications for particle acceleration and γ-ray emission by such systems. We argue that the particle density in the magnetospheres of such stars is larger by orders of magnitude than the Goldreich-Julian density, so that the formation of vacuum gaps is unlikely. We show that even if the star rotates slowly, electromotive forces ( EMFs ) of order 1015 V are produced by the interaction of plasma in the accretion disk with the magnetic field of the neutron star. The resistance of the disk-magnetosphere-star circuit is small, and hence these EMFs drive very large conduction currents. Such large currents are likely to produce magnetospheric instabilities, such as relativistic double layers and reconnection events, that can accelerate electrons or ions to very high energies.

Subject headings: acceleration of particles — accretion, accretion disks — MHD — stars: neutron
Evolution of Supernova Remnants with Cosmic Rays and Radiative Cooling
Authors: Dorfi E. A.
Published: July 2016

Recent numerical models for SNR evolution are presented, including first-order Fermi acceleration with injection of suprathermal particles at the shock wave, heating due to dissipation of Alfvén waves in the precursor region and radiative cooling of the thermal plasma. The X-ray fluxes obtained from these SNR models show significant differences depending on the acceleration efficiency of cosmic rays. γ-ray fluxes are calculated originating from π0-decay of pions generated by collisions of the high-energy particles with the thermal plasma. Cooling of the thermal plasma and dissipation of Alfvén waves in the precursor are important to determine the final amount of the explosion energy ESN which is transferred into cosmic rays.

Subject headings: acceleration of particles — cosmic rays — gamma rays: theory — shock waves — supernova remnants
Polarized One-Quantum Annihilation in Strong Magnetic Fields as a Process for Particle Deceleration in Neutron Star Atmospheres
Authors: Berg D. , Mentzel M. , Wunner G.
Published: July 2016

Since several gamma-ray bursts seem to have their origin in the vicinity of neutron stars, where strong magnetic fields are present (B ≃ 108T), electrons and positrons have to be described, in this instance, by relativistic Landau states. As is well known, strong magnetic fields produce important effects: motion perpendicular to the field is quantized, transverse momentum is not conserved, and polarization effects become important. Moreover, in contrast to the field-free case, exotic processes such as 1γ pair-annihilation are not forbidden. With growing magnetic field, the cross section of this process becomes more and more nonnegligible. This cross section strongly depends on the polarization of the electron-positron pairs. Thus the deceleration via annihilation turns out to be a strongly polarization-dependent phenomenon in magnetized electron-positron plasmas.

Subject headings: acceleration of particles — gamma rays: theory — polarization — radiation mechanisms: nonthermal — stars: neutron
Do Relativistic Electrons Either Gain or Lose Energy, Outside of Extragalactic Nuclei?
Authors: Rudnick Lawrence , Katz-Stone Debora M. , Anderson Martha C.
Published: July 2016

In the generally accepted models of high-luminosity extragalactic radio sources, the relativistic electron distribution evolves significantly outside of its source in the galactic nucleus; synchrotron losses occur throughout the source, and the harder (flatter) spectra seen in the hot spots are one indicator of relativistic particle acceleration. Our reanalysis and interpretation of the Carilli et al. (1991) data on Cygnus A, on the other hand, showed no evidence for evolution of the electron distribution function, and no evidence of the universally assumed injection power-law distribution. Having found a spectrum that describes an entire source, we have also introduced the technique of correcting synchrotron maps for frequency-dependent effects. In this way, a partial deconvolution of the underlying physical parameters is possible. In Cygnus A, this correction procedure led to the dominance of a hitherto unrecognized structure, an edge-brightened channel girdled by rings. We briefly discuss some implications of this work and our plans to continue this line of investigation.

Subject headings: acceleration of particles — galaxies: individual (Cygnus A) — galaxies: nuclei — radiation mechanisms: nonthermal — radio continuum: galaxies
Time-Dependent Simulation of Cosmic-Ray Shocks, Including Alfvén Transport
Authors: Jones T. W.
Published: July 2016

Time evolution of plane, cosmic-ray modified shocks has been simulated numerically for the case with parallel magnetic fields. Computations were done in a “three-fluid” dynamical model incorporating cosmic-ray and Alfvén-wave energy transport equations. Nonlinear feedback from the cosmic rays and Alfvén waves is included in the equation of motion for the underlying plasma, as is the finite propagation speed and energy dissipation of the Alfvén waves. Exploratory results confirm earlier, steady state analyses that found these Alfvén transport effects to be potentially important when the upstream Alfvén speed and gas sound speeds are comparable. As noted earlier, Alfvén transport effects tend to reduce the transfer of energy through a shock from gas to energetic particles. These studies show as well that the timescale for modification of the shock is altered in nonlinear ways. It is clear, however, that the consequences of Alfvén transport are strongly model dependent and that both advection of cosmic rays by the waves and dissipation of wave energy in the plasma will be important to model correctly when quantitative results are needed. Comparison is made between simulations based on a constant diffusion coefficient and more realistic diffusion models allowing the diffusion coefficient to vary in response to changes in Alfvén wave intensity. No really substantive differences were found between them.

Subject headings: cosmic rays — MHD — shock waves
The All Sky Automated Survey (ASAS-3) System – Its Operation and Preliminary Data
Authors: Pojmański G.
Published: July 2016

ASAS-3 is the next step in the All Sky Automated Survey. This paper describes the new hardware, consisting of two wide field (9 × 9 deg) telephoto instruments and one F = 750 mm D = 250 mm telescope with 2 × 2 deg FOV, each equipped with a 2K × 2K CCD camera. Wide field instruments are now observing the whole southern sky (almost 30,000 sq. deg) at the average rate of 0.5 measurements per day. A narrow field instrument is connected to the GCN network and is ready to respond to the GRB alerts in tens of seconds. Preliminary photometric data are presented here and briefly discussed.
A Robotic Wide-Angle Hα Survey of the Southern Sky
Authors: Gaustad John E. , Rosing Wayne , McCullough Peter , Van Buren Dave
Published: July 2016

We are conducting a robotic wide-angle imaging survey of the southern sky at 656.3 nm wavelength, the Hα emission line of hydrogen. Each image of the survey covers an area of the sky 13° square at an angular resolution of approximately one arcminute, and reaches a sensitivity level of 0.5 Rayleigh (3 × 10−18erg cm−2s−1arcsec−2), corresponding to an emission measure of 1 cm−6pc, and to a brightness temperature for microwave free-free emission of 3 µK at 30 GHz.
Long-period Red Variables in the Large Magellanic Cloud from the MOA Database
Authors: Takeuti Mine , Noda S. , Abe F. , Bond I. A. , Dodd R. J. , Hearnshaw J. B. , Honda M. , Jugaku J. , Kabe S. , Kilmartin P. M. , Matsubara Y. , Masuda K. , Muraki Y. , Nakamura T. , Nankivell G. R. , Noguchi C. , Ohnishi K. , Rattenbury N. J. , Reid M. , Saito To. , Sato H. , Sekiguchi M. , Skuljan J. , Sullivan D.J. , Sumi T. , Watase Y. , Yanagisawa T. , Yock P. C. M. , Yoshizawa M.
Published: July 2016

We studied 147 long-period red variable stars in the Large Magellanic Cloud from the MOA database. Amongst them, seven red luminous stars are likely pulsating in a higher mode.
The Carl Sagan Observatory: A Telescope for Everyone
Authors: Saucedo-Morales J. , Sánchez-Ibarra A. , Lunt D.
Published: July 2016

The Carl Sagan Observatory is a new project for a remote observatory that will be built at the summit of Cerro Azul (a 2480 m mountain located near Magdalena. Sonora, México). It will include one 55 cm and four 14 cm telescopes. The 55 cm telescope will be dedicated to supernovae research. One of the 14 cm Maksutov telescopes will be used as an autoguider for the stellar observations. The other 14 cm telescopes will feature different narrow band filters that will be used for solar research. The observatory will be controlled from the campus of the Universidad de Sonora in Hermosillo, Sonora, México (~ 200 km from the site). A prototype of the observatory building has been built on campus and first light is expected by the end of May of 2001. We expect to have an operating mountain observatory by the end of 2002. Some of the unique technical aspects of this observatory, which we believe can be a model for future small telescope observatories are discussed in this work.
The NCU Lu-Lin Observatory
Authors: Tsay Wean-Shun , Chen Alfred Bing-Chih , Chang Kuang-Hsiang , Li Huan-Hsin
Published: July 2016

The NCU (National Central University) Lu-Lin observatory is located at Mt. Front Lu-Lin, 120°52′25”E and 23°28′07” N, a 2862-m peak in the Yu-Shan National Park. The construction of Lu-Lin observatory was finished on January 14, 1999. The initial assessment of Lu-Lin site started in 1989, after which a three-year project was founded by the National Science Council (NSC) to support a modern seeing monitoring program. The average seeing at Lu-Lin is about 1.39 arc-second with an average of 200 clear nights annually. The sky background is 20.72 mag/arcsec2 in V band and 21.22 mag/arcsec2 in B band.

The Lu-Lin observatory is for both research and education. A homemade 76-cm Super Light Telescope (SLT) and four TAOS 50-cm robotic telescopes for a survey on Kuiper Belt Objects will be the two major research facilities. The pilot program for SLT consists of observations of time-varying astrophysical phenomena. The TAOS #1 telescope was installed at Lu-Lin in March 2000. A 90 KW/240 VAC power line and a water pipe system have been pulled to the site in early 2001. A wireless Network system through A-Li Shan has been operating at Lu-Lin observatory while a faster wireless Network system with 11.5 Mbit/sec bandwidth is under consideration and may be available in the near future for remote observing.
Advantages and Drawbacks of the ISM Method in Globular Cluster Photometry
Authors: Benkő József M.
Published: July 2016

In the framework of our survey of variable stars in galactic globular clusters, we tested the promising new photometric technique, the Image Subtraction Method (Alard & Lupton 1998, Alard 2000). We found that the standard deviations of light curves are much better compared to those of the more common PSF methods (e.g. DAOPHOT), especially in the most crowded regions. Moreover, many additional variable stars have become measurable with this method. Unlike previously published data we have transformed our results into conventional magnitudes. The accuracies of the derived magnitudes are discussed.
The Kinematics of Globular Cluster NGC 288
Authors: Chang Chan-Kao , Chen Alfred B. , Tsay Wean-Shun , Chen Wen-Ping , Lu Phillip K.
Published: July 2016

The mean radial velocity of NGC 288 (accuracy 5.5 km/s) is determined to be −56.3 ± 20.1 km/s which, when combined with the mean proper motion (Guo, 1995), yields a peculiar velocity with respect to the LSR of (u,v,w) = (29.7 ± 18.1, −258.6 ± 18.3,62.3 ± 20.3) km/s. This implies that NGC 288 moves in a retrograde sense with the Galactic rotation. We also derived the effective temperatures for stars in our sample and, as a corroborative effort, compared with those estimated previously from the BATC data (Tsai 1998) by spectral energy distribution fitting. We demonstrate that the BATC/SED fitting is an appropriate and efficient way to estimate the effective temperature of a star.
Former Soviet Union / West Europe Consortium for AGN Monitoring
Authors: Bochkarev N.G. , Shapovalova A.I. , Burenkov A.N.
Published: July 2016

In the same year as Blandford and McKee (1982), Prof. N. Bochkarev and Dr. I. Antokhin (Bochkarev and Antokhin, 1982) published an article on the reverberation method of AGN BLR structure analysis. In 1983, testing observations were carried out with the 6 m telescope.

From 1986 up to now spectral monitoring of several AGNs has been carried out at SAO RAS (North Caucasus). Since 1988 we have been participating in AGN Watch Program. Since 1997 we have been carrying on an international program that is realised at several observatories of CIS (former Soviet Union) in collaboration with several West-European scientific groups (Bochkarev and Shapovalova, 1999). Some spectra of 3C390.3, one of the dimmest target objects of our program, m = 15.6 mag, taken with different telescopes are presented in Fig. 1(left).
The Transfer of Large-scale Magnetic Field by Radial Inhomogeneity of the Material Density in the Rotating Convection Zone
Authors: Krivodubskij V.N. , Kichatinov L.L.
Published: July 2016

The influence of rotation on the transfer of the mean magnetic field of the Sun, caused by the radial inhomogeneity of the solar turbulent plasma density, is investigated. It turns out that the transfer directions of the poloidal and toroidal magnetic fields do not coincide.
Solar Internal Rotation, the Boundary Layer Dynamo and Latitude Distribution of Activity Belts
Authors: Belvedere G. , Proctor M.R.E. , Lanzafame G.
Published: July 2016

We suggest that the latitude distribution of solar activity belts and the related equatorward or poleward migration of different tracers of the solar cycle are a natural consequence of the internal radial profile of angular velocity via the working of a dynamo in the boundary layer beneath the convection zone. This has been confirmed by the results of a non-linear dynamo model in a very thin spherical shell which show that dynamo action may reasonably take place in the boundary layer and reproduce the observed surface phenomenology.

Extending the argument to late main-sequence stars, it is reasonable to think that observations of the latitude distribution and migration of stellar active regions by current sophisticated techniques may make it possible to infer their internal rotation profile in a simple and direct way.
The Variations of the Hα line of HD199178
Authors: Jetsu Lauri , Savanov Igor , Tuominen Ilkka
Published: July 2016

Changes of emission cause variations of the Hα absorption line of HD 199178. The correlation with the simultaneous light curve may depend on the relative strength of the axisymmetric and non-axisymmetric components of the evolving spot configurations.
Full Phase Coverage of BY Dra with the VLA
Authors: Caillault Jean-Pierre , Drake Stephen
Published: July 2016

We have obtained 21 ~one-hour observations of the prototypical spotted star, BY Dra, with the VLA. These data are sufficiently well spaced in time to allow for complete rotational and orbital phase coverage; the resultant radio light curves are compared to their optical counterpart. We also plot the emission versus time without phase-folding, in order to search for longer periods of activity. Splitting the data into smaller (three minute) time bins allows for the determination of the normalized amplitude distribution of the flux; we compare this with known stellar optical and X-ray flare distributions.
Spectral Line Variations in Ap Stars
Authors: Wood H. John
Published: July 2016

It is the purpose of this review to outline the historical and present uses of time-dependent line-strength studies of Ap stars. One cannot ignore other important types of time-dependent observations such as photoelectric photometry in intermediate and broad bands, or radial velocity curves for selected lines in an Ap star. However, we will attempt to show how line variation studies can provide unique and sometimes crucial tests of theories and models.

It would be impossible in this brief paper to mention all the relevant papers we have found during this survey of the literature. Indeed, it is remarkable that this field has been so active over the past 70 years and yet it remains so controversal.
Photoelectric Magnetic Field Measurements of Ap and Bp Stars
Authors: Landstreet J.D. , Borra Ermanno F.
Published: July 2016

Magnetic field measurements of numerous Ap and Bp stars have been obtained using a photoelectric technique similar to that employed in the solar magnetograph, applied to Balmer line wings. The accuracy of field measurements obtained is almost independent of projected rotation velocity. A survey of rapidly rotating (v. sin i ≥ 30 km/sec) Ap stars shows that fields of more than 1 kgauss are significantly less common among rapidly rotating Ap stars than among slowly rotating ones. Magnetic fields have been found in two rapidly rotating Ap stars, four southern Ap stars, and the helium-weak star 3 Sco. Magnetic curves obtained for the known magnetic stars 53 Cam and α2CVn show significant differences from the curves observed photographically, in ways which can alter conclusions drawn about the field distributions over the surface of these stars.
Differential Curve-of-Growth Analyses of Mn-Hg Stars
Authors: Kodaira Keiichi
Published: July 2016

Spectra of eleven Mn-Hg stars (α And,μ Lep, 129 Tau, 14 Hya,κCnc, 30 UMa, πBoo, ι CrB, ϕ Her, ν Her, 46 Dra) are analyzed by the curve-of-growth method. The effective temperature and the surface gravity are estimated from the |u-b|- and the β-indexes and fall into ranges O.346 ≤ θe≤0.451 and 3.4≤log g≤3.8. The microturbulence velocity is found to be in a narrow range of 2 ≲ vt≲ 4.5 km/sec. The resulting chemical composition is very similar among the eleven Mn-Hg stars and shows following characteristics:

1)

The abundance ratios N(C):N(Si):N(Ca):N(Fe), N(Ti):N(Cr) and N(Sr):N(Y):N(Zr) are nearly identical to those of the sun.

2)

The enrichment factors relative to Fe are about 10 for Ti and Cr, about 100 for P, Sc, Mn, Sr, Y, and Zr, about 105for Ga, and about 103~106(varying among stars) for Hg.
Photometric Observations of the Metallic Line Stars Around 3600 Å
Authors: Gerbaldi M. , Morguleff N.
Published: July 2016

Analysis of the metallic line stars in the narrow band photometric system Barbier-Morguleff shows an important blocking effect around 3600 Å.

For 14 metallic line stars Celescope observations suggest around 2300 Å a blocking effect not so strong as in U filter.
New Celestial Reference System
Authors: Seidelmann P. K. , Kaplan G. H. , Van Flandern T. C.
Published: July 2016

The IAU (1976) System of Astronomical Constants, the FK5 and new lunar and planetary theories are being introduced in 1984. The investigation and planning for the transition has revealed the complex interdependencies between observational techniques and the reference systems, and their strong link to the rotating and orbiting Earth. The inaccuracies in our knowledge of the star positions, astronomical constants and the rotation and motion of the Earth are embedded in subtle ways in the observations and the reference coordinate systems. For example, the FK4 reference system in 1950.0 coordinates rotates with respect to an inertial system. Details are given for the conversion to the new system.
Orientation of FK4 System from Meridian Observations of Planets
Authors: Duma D.P. , Kizjun L.N. , Safronov Yu.I.
Published: July 2016

The orientation of the FK4 coordinate axes was made by two methods: using the classical interpretation of the orientation problem and by the new method suggested and developed at the Main Astronomical Observatory.
Herschel’s Scientific Apprenticeship and the Discovery of Uranus
Authors: Bennett J.A.
Published: July 2016

In 1784 Jean-Dominique Cassini, who as Director of the Paris Observatory was one of the foremost professional astronomers of his day, wrote

‘A discovery so unexpected could only have singular circumstances, for it was not due to an astronomer and the marvellous telescope….was not the work of an optician; it was Mr Herschel, an English musician, to whom we owe the knowledge of this seventh principal planet (Schaffer, 1981, 21).
The Stellar Data Center
Authors: Jaschek C.
Published: July 2016

The paper presents an overview of the problems astronomical data centers are facing today.

When one organizes a colloquium, one can do some fairly outrageous things, like putting ones own contribution first . However as an excuse for such a procedure, I shall say that I want really not to discuss that much what the C.D.S. itself does, but what problems we have been confronted with, specially those which came up since the last Strasbourg colloquium, or which got more complicated to handle.
Management of Astronomical Data at Kanazawa Data Center
Authors: Terashita Yoichi
Published: July 2016

The methods of controlling and disseminating astronomical data at the Kanazawa Data Center (operated under the Computer Center of the Kanazawa Institute of Technology) are described. Discussions include the coded data descriptions used in conjunction with a file processing language. Problems concerning remote data access are also discussed, and the future plan presented.
Infrared Astronomical Data Base and Catalog of Infrared Observations
Authors: Schmitz Marion , Gezari Daniel Y. , Mead Jaylee M.
Published: July 2016

A computer data base of infrared astronomical observations has been established at NASA/Goddard Space Flight Center. It contains a summary of all infrared (1µm-1000µm) observations of celestial sources outside the solar system, published in the major scientific journals since 1960, as well as the contents of infrared surveys and catalogs. A Catalog of Infrared Observations (CIO) has been developed from the data base in printed and magnetic tape versions. A bibliographic Guide to the Infrared Astronomical Literature, and an Atlas of Infrared Source Names and Positions will be published in conjunction with the catalog. Future plans include development of an interactive data system at Goddard which will give a user direct access to the computerized data.
A process for retrieval of data from a compiled star catalogue
Authors: Stein William
Published: July 2016

For certain space vehicles there is a need to accurately determine vehicle attitude. Some of these spacecraft, such as NASA’s planned LANDSAT-D and Gamma Ray Explorer, will use observations from star sensors to determine fine attitude. One input to the attitude determination software is a specialized stellar data base. The initial step in this software is to identify and match the star images with catalogue stars. The Naval Surface Weapons Center (NSWC) has compiled a special star catalogue for such applications. This paper describes the criteria for the NSWC catalogue and how it is utilized. Because of the large number of stars available, a subset can be divided into cells defined by mission criteria. The cells are stored as a random access mass storage file, thus allowing quick access to the information. This greatly reduces execution time for the software. One scheme for accessing stars from mass storage is described.
Responsibilities and practical limitations in the operation of an astronomical data center
Authors: Warren Wayne H. , Mead Jaylee M. , Nagy Theresa A.
Published: July 2016

The operation of an astronomical data center requires that many decisions be made concerning the handling of the astronomical catalogs and data distributed. Should a data center be, as Wilkins (1977) described it, passive, in that catalogs and data are collected and distributed blackbox-wise upon request, or should a data center be active and have experts in various fields to scrutinize, correct, reformat, and document data where necessary? These questions will be addressed and illustrated by describing the current operations and future goals of the Astronomical Data Center at NASA/GSFC.
Proton Induced X-Ray Emission (Pixe) Analysis of Meteoritic Microsamples
Authors: Wallenwein R. , Blank H. , Jessberger E.K. , Traxel K.
Published: July 2016

Interplanetary dust particles (IDPs) collected in the stratosphere are thought to be mostly of cometary origin. They survived heating during their deceleration in the earth’s atmosphere (1). Because of their small size (< 50 μm ) and mass (< 10−7 g) they are difficult to analyse. Special preparation and examination methods have been developed for their investigations (2). We set out to study the trace-element-composition of these particles using the Heidelberg proton microprobe.
Laboratory Infrared Transmission Measurements of Interplanetary Dust and Implications for Remote Observations of Cosmic Particles
Authors: Sandford S.A. , Walker R.M.
Published: July 2016

Laboratory infrared absorption spectra of interplanetary dust particles show that most fall into one of three spectral groups (1) designated as “pyroxenes”, “olivines”, and “hydrated silicates”.

Comparisons with 10 μm emission data from Comet Kohoutek (2) show that no single spectral type matches the cometary data. However, a reasonable match is obtained by coadding equal amounts of pyroxene and hydrated silicate type spectra.

The possibility that the 10 μm feature seen in some comets is due to a combination of these two components can be tested in two ways. First, the pyroxene type spectra show detailed features of variable position and strength within their 10 μm bands. Based on the laboratory data we estimate that comet spectra taken at a resolution of λ/Δλ ~ 200 would be sufficient to find these features, if present. The magnitude of these features is expected to be ≤ 0.1 of the maximum strength of the 10 μm band.

Second, the hydrated silicate particles usually have bands at 3.0, 6.2, and 6.9 µm. The first two bands are probably linked to the presence of water while the 6.9 μm band is probably due to carbonates. The 3.0 μm feature is broad and might be hard to separate from thermal background. However, spectra taken at resolutions of λ/Δλ ~ 50 could see the 6.2 and 6.9 μm bands. The strengths of these bands (which are also seen in the spectra of CM meteorites) vary (one particle has a carbonate band that is actually stronger than its corresponding 10 μm silicate band), but are typically ~0.1 the depth of the silicate features. A second, narrow carbonate band at 11.4 μm can also sometimes be seen in particle spectra but its strength is less than that of the 6.9 μm band. This the search for the 6.2 and 6.9 μm bands in astronomical objects, while not requiring high resolutions, would require good S/N.
Planetary Perturbations: Effects on the Shape of a Cloud of Dust in Circular Heliocentric Orbits
Authors: Gustafson Bo Å. S.
Published: July 2016

Synthetic infrared pictures are used to illustrate changes in the shape of portions of an interplanetary dust-cloud. The dust particles, in circular heliocentric orbits, are perturbed by radiation and corpuscular forces combined with gravitational disturbances by the major planets. Dust in the inner solar system and close to the ecliptic or the orbital plane of Venus is brought to a more narrow range of ecliptic latitudes. A dust-band evolves near and inside the orbit of Venus. The cloud’s shape is less affected at high ecliptic latitudes.
The Solar Wind Generation Experiment for Spartan Mission 201
Authors: Kohl J.L. , Weiser H. , Withbroe G.L. , Munro R.H.
Published: July 2016

The Solar Wind Generation Experiment consists of a UV Coronal Spectrometer (UVCS) provided by the Harvard-Smithsonian Center for Astrophysics and a White Light Coronagraph (WLC) of the High Altitude Observatory. The instruments are similar to those flown together on three sounding rocket flights [1,2,3] but they have enhanced capabilities to take advantage of Spartan’s 27 hour observing period. The two instruments comprise a payload for Spartan 2, which is a self-contained instrument carrier that provides on-board data storage, power, thermal control, sun pointing and an observing program sequencer. Spartan is launched and deployed by the Shuttle and spends about 27 orbits in a detached mode before it is recovered and returned to the ground for data tape retrieval and post-flight instrument calibration.
HRTS Evidence for Rotation of Transition Region Temperature Spicules
Authors: Cook J.W. , Brueckner G.E. , Bartoe J.-D.F. , Socker D.G.
Published: July 2016

The HRTS (High Resolution Telescope and Spectrograph) instrument is a high spectral (0.05 Å) and spatial (<1 arc sec) resolution spectrograph with a slit length of 900 arc sec on the solar disk (see Bartoe and Brueckner 1975, 1978). HRTS contains in addition a double grating, zero dispersion broadband spectroheliograph which images the spectrograph slit jaw plate (see Cook et al. 1983). The central wavelength is tunable by changing the grating geometry. Hα images are also photographed from the slit jaw plate image. HRTS has been flown four times as a rocket payload, and will fly in April 1985 as one of the solar experiments aboard Spacelab 2. The four rocket flights of the HRTS program have each been customized for a particular scientific objective. For the fourth flight, because the original hardware was utilized as the basis of the Spacelab HRTS, the opportunity was used to design and build a new rocket HRTS instrument specialized for observations at the solar limb. In this configuration the photographic speed was increased, a new curved slit was fabricated, and the spectroheliograph was modified for limb observations. The scientific observing program was a study of structure and short term temporal evolution at the limb, with a comparison of quiet and coronal hole areas.
Recombination Process from a Metastable State
Authors: Kato T. , Masai K. , Sato K.
Published: July 2016

The level 2s2p2(4P) of OIV is a metastable state and the line intensity Ii (2p3(4S) − 2s2p2(4P)) is mainly generated by the excitation from the metastable state 2s2p2(4P) to 2p3(4S). Then the line intensity ratio is Ii to the resonance line intensity Ir (2s2p2(2D) − 2s22p(2P)) has a dependence on electron density until the metastable level is saturated. The ratio Ii/Ir obtained from the measurements of JIPPT-IIU Tokamak plasmas has Been analyzed. It is found that the recombination from a metastable state of OV 2s2p(3P) to the metastable state of OIV 2s2p2(4P) is appreciable in high temperature plasmas where the abundance of OV is larger than that of OIV. The recombination rate coefficient between metastable states is determined from-the line intensity ratios; I(2p2(3P) − 2s2p(3P))/I(2s2p(1P) − 2s2(1S)) of OV, (2s2p2(2D) − 2s22p(2P)) and Ii/Ir of OIV. This recombination process consists of dielectronic recombination and radiative recombination.
A Comparison of Various NLTE Codes in Computing the Charge-State Populations of an Argon Plasma
Authors: Stone Sam R. , Weisheit Jon C.
Published: July 2016

A comparison among nine computer codes shows surprisingly large differences where it had been believed that the computational physics was well understood. The codes simulate a plasma that is in steady state but not in local thermodynamic equilibrium (NLTE codes). In this study each code treats an “easy” problem, which is an argon plasma, optically thin and with no external photon flux; densities are varied from near-coronal to an intermediate 1021 electrons/cc and above. The temperatures are high enough that most ions have two or fewer bound electrons, which for this plasma means temperatures above about 300 eV.

The present study asks only if the codes compute similar charge-state populations (a surprising “no”), and, if not, why not. It does not claim accuracy for any code either by comparison to experiment or by appeal to a concensus.
High-Resolution Photoabsorption Spectrum of Cs+ (5p61So + 5p5ns, nd) Between 504A and 600A using a Laser Ionized Cs Vapor Column
Authors: McIlrath T.J. , Kaufman V. , Sugar J. , Hill W.T. , Cooper D.
Published: July 2016

Rapid ionization of Cs vapor in a heat pipe at 0.05 torr was achieved by pumping the 6s 2S½ – 7p 2P½ transition (f=0.007)1 with a flash-pumped dye laser at 4593.2A and I MW power output. Photoabsorptian initiated at the end of the laser pulse(≃ 0.5/s) showed the 5p5ns and nd series below and above the 5p52P3/2 threshold at 535.4A. Broad Beutler - Fano resonances appeared in the d series above threshold. The spectrum was recorded photographically on a 10.7m grazing incidence spectrograph using a continuum background generated by a BRV high-voltage spark source with a uranium anode. We will compare the line-shapes and the quantum defect (Lu-Fano2) plot with the predictions of a relativistic random phase calculation.
High Resolution Lithium Like Satellites to the IS2IS0 – ls 3p 1P1 Line in Laser-Produced Dense Plasmas
Authors: Audebert P. , Geindre J.P. , Gauthier J.C. , Alaterre Ph. , Popovics C. , Cornille M. , Dubau J.
Published: July 2016

The dielectronic satellite lines from the ls21a 3lb and ls31a 31b, double-excited configurations of lithium-like ions have been studied experimentally and theoretically under dense-plasma conditions. Good agreement between theory and measurements performed in laser-target interactions at 0.53 m wavelength, 1014 W/cm2 laser irradiance show that collisional equilibrium conditions are reached between n − 3 singly and double excited levels at electron densities greater than 1022 cm−3 in Al and Si.
Compact Binary X-Ray Sources
Authors: McCray Richard
Published: July 2016

Compact binary X-ray sources include white dwarfs, neutron stars, and black holes that are accreting matter from a companion star. The X-ray emission from these systems is produced by the accreting matter as it flows through an accretion disk and strikes the surface of the compact object. The emitting regions have opacities dominated by electron scattering, and radiation pressure is likely to play an important role in the hydrodynamics. Strong magnetic fields greatly modify the hydrodynamics and radiation transfer in the pulsating neutron star sources. Accretion disks have complex structure, including an electron scattering corona, a cool outer region, and possibly a thick torus in their inner region. The structure and stability properties of accretion disks are only partially understood. Major problems exist with the interpretation of the spectra and luminosities of the X-ray burst sources. The pulsed X-ray emission from the pulsating binary X-ray sources probably comes from “mounds” of accreting gas at the magnetic poles of neutron stars, in which the accreting matter is decelerated by radiation pressure. The physics of these systems is reviewed, with an emphasis on problems for which hydrodynamical simulations may be especially useful.
Curriculum for the Training of Astronomers
Authors: Narlikar Jayant V.
Published: July 2016

In a discussion on the training of astronomers, the question naturally arises: “Training...but at what level?” After all, the subject of astronomy happens to be unique amongst all sciences in that it interests children and educated general public at one end and professionals at the other. Before coming to these specifics, certain general remarks will be in order.

Astronomy is a branch of science. This fact is not readily appreciated at the “lay” end of the above spectrum. Unlike other sciences, which have Earth-based laboratories in which controlled experiments are performed, astronomy has its labs located in the heavens far beyond the reach, let alone “control,” of the terrestrial observer. So how can one be sure that what one sees out there is subject to the same rules and disciplines of science that govern the local laboratory experiments of physics and chemistry? Yet that happens to be so!
A Self-Paced Mastery-Oriented Introductory Astronomy Course
Authors: Safko John L.
Published: July 2016

I will be describing a self-paced mastery-oriented introductory astronomy course that has been offered at the University of South Carolina since 1972. This course is a three-semester sequence with total enrollments of 800–1000 students per term. Most of the enrollment is for the first semester of the sequence. Although these particular courses are designed for non-science majors, I believe that the methods developed in these courses can be applied to courses for astronomy majors. These methods could provide a solution to the problems of teaching classes and, at the same time, traveling for research and meetings.

A mastery-oriented course involves developing a list of learning objectives that are described in terms of performance of given tasks. That is, words such as understand and appreciate should not be used. Performance objectives involve words such as recognize, calculate, measure, and describe. Any set of learning objectives must be tied to a set or readings, a textbook, and/or supplementary notes. These items are chosen or written by the instructor(s) to provide the background necessary for the students to master the objectives.
Classification of Stellar Spectra
Authors: Dworetsky M.M.
Published: July 2016

The objectives of this exercise are to gain familiarity with the appearance of the spectra of stars, to understand some of the temperature and luminosity criteria used to classify spectra, and to gain insights into the relationship between the appearance of stellar spectra and physical conditions in stellar atmospheres.
Modern Photometry Lab Exercises for Students in Introductory Astronomy
Authors: Caton Daniel B.
Published: July 2016

Introductory astronomy lab exercises have traditionally been rather simple in nature — observations are often limited to visual observing, sketching, and perhaps photography. These types of labs are more like 19th-century astronomy than the techniques used by modern astronomers. Students should also be introduced to quantitative work in astronomy, in the same way that they are in equivalent introductory physics and chemistry labs. A typical solution to some of these problems has been to use published data (for example, the Sky & Telescope lab exercise series) to provide numerical work. This is less satisfactory for the student than obtaining his or her own quantitative data to reduce and analyze.
Laboratory Activities in the Teaching of Astronomy
Authors: Osborn Wayne
Published: July 2016

Astronomy is one of the most popular of the sciences. That this is so can be seen in the frequent news articles about astronomical discoveries and happenings, in the number of questions about the sky fielded by planetarium and observatory staff, and in the large turnouts for public observing sessions at observatories or astronomy club star parties.

Another reflection of astronomy’s popularity is the fact that thousands of university students study the subject each year. Only a few of these are training to become professional astronomers. The vast majority of these students seek mainly to obtain a general background. An important subset of the latter group are those students preparing to teach in the schools and who have the need to understand, and be able to explain, common astronomical phenomena clearly. Those of us who teach introductory astronomy courses have an obligation to ensure that these prospective teachers are well trained.
Microcomputers in the Teaching of Astronomy
Authors: Dukes Robert J.
Published: July 2016

There are many ways to use computers in teaching. This paper discusses one of those ways: as an adjunct to the introductory astronomy course as taught in the United States.

The computer allows the demonstration of phenomena in a graphic dynamic manner, so its use can enable students to gain a deeper understanding of the material than they might when they passively listen to a lecture, look at slides, or study a textbook. In a very real sense, material presented in a computer is similar to that presented by film or video, but with one major difference: viewing movies is essentially a passive experience while interacting with a computer is an active one. Using computer simulations, the user can vary initial conditions and observe the effect of changes. This ability is the case whether the person doing the interacting is the instructor during a lecture or the student during a lab or while independently executing a homework exercise.
Five Centuries of Astronomical Textbooks and their Role in Teaching
Authors: Gingerich Owen
Published: July 2016

At the turn of the century, astronomy was required of every senior in what is now the American University of Beirut, for the reason that “the heavens declare the glory of God”; this was especially appropriate for what was then the Syrian Protestant College. And in the late Middle Ages, astronomy was one of the seven liberal arts, a required part of every basic university education — for much the same reason. Thus, for many centuries, astronomy was considered essential for what every educated person should know. The organizers of this colloquium thought it would be informative to learn more about the historical background to our colloquium and asked if I would speak on the history of astronomy teaching over the ages. I demurred at such an overwhelming topic, which would require a major research program, and have offered instead something about the history of astronomy textbooks, because this subset provides answers to at least some of the broader questions of how astronomy has been taught.
Textbooks for Developing Countries
Authors: Othman Mazlan
Published: July 2016

I would like to address the issue of textbooks from a developing country’s point of view.

Firstly, I believe that in the developing countries a textbook should be written in the native language if it is to reach the very people whose awareness of astronomy needs to be raised. And when we talk about books in the vernacular, the problem is one of dearth: a dearth of writers and a dearth of resources.

The lack of writers comes about simply because in the developing nations there are inevitably very few astronomers and of these only one or two will be inclined to write books. If there exist writers, they are faced with several choices and problems. There are three types of books which can be written: a university text, a school text, and I shall include a book for the public. Each type of book targets a different kind of audience, so the writer must be attuned to the needs of the nation to know what the priority should be. If, for example, astronomy is about to be introduced into a school curriculum, then a school textbook should take the highest priority because it tackles astronomy education at the grass-roots level. Naturally, the final choice will depend on other factors as well, including promotion, fame, and pecuniary considerations.
Science Teaching through its Astronomical Roots
Authors: Sadler Philip M. , Luzader William M. ,   Project STAR
Published: July 2016

Project STAR (Science Teaching through its Astronomical Roots) emerged from growing concern about the decreasing enrollment in science classes, and lack of understanding of science and math concepts (Figure 1). Using astronomy as a focus, Project STAR is trying not simply to increase the enrollment in high school science courses, but also to improve the students’ understanding of science and its role in making sense of the world.

The educational approach of Project STAR is based on three principles:

• Mastery of a few ideas is more important for students than cursory exposure to many concepts.

• Students learn best through hands-on activities.

• Students enter the classroom with certain preconceptions, or “naive theories,” about how physical systems work, without a sense of whether their understandings are accurate (often they are not).
The Week-End Astronomy Class for Teachers
Authors: Hensley James H.
Published: July 2016

Astronomy is an integral part of many high-school science programs. Project STAR and the Science Assessment and Research Project at the University of Minnesota have recently recognized this. In addition, astronomy is a part of most elementary and middle-school science programs. In the Platteville, Wisconsin, school system, the solar system is a unit of study for all third grade students and a study of the stars is a part of the eighth grade science program. This is also true for other school systems in this area, in the Chicago area, and I would suspect, across the nation.

However, most elementary school teachers have had little science course work and none in astronomy. Middle-school and high-school teachers have better backgrounds for teaching science but little or no astronomy course work. Some of those who teach astronomy are active in local astronomy groups and read Astronomy or Sky and Telescope magazines, but this is the exception rather than the rule.
The Didactic Activities of the Italian Astronomical Society
Authors: Pestellini M. Elena Dilaghi
Published: July 2016

The Italian Astronomical Society is one of the oldest Italian scientific associations: founded in Rome in 1871 as the Society for Italian Spectroscopists, it includes professional as well as amateur astronomers and teachers among its 800 members.

In the last 10 years, the Society has been concerned with the problems of teaching, as a result of the enormous demand from schools where astronomy is often not well taught at any level because of a lack of suitable qualified teachers.

To meet this need, the Society publishes a quarterly journal entitled Il Giornale di Astronomia, which includes news of astronomical events, informative articles and accounts of didactic experiences as well as other information that may be helpful to teachers of astronomy.
The Teaching of Astronomy and Social and Economic Development
Authors: Vicino Gonzalo
Published: July 2016

Sometimes we may ask ourselves how can astronomy, a science with apparently few points of contact with technology or industrial production, help the economic development of people?

My paper is an account of an experiment undertaken in Uruguay on the teaching of astronomy in secondary schools. We seek to show how astronomy may contribute to the development of nations that, like Uruguay, need to create their own technologies to overcome their economic backwardness.

Though the introduction of astronomy in the secondary education curriculum in Uruguay dates back to 1889, in 1986 the Educational Supervisory Office made a radically different proposal for the methodological and programmatic orientation of astronomy teaching. The proposed goal is clear: the teaching of astronomy in secondary education should be geared not to train technicians but to create a scientific-minded youth. It is not important if later, in their university studies, these young people go into medicine, engineering, or economics; the important thing is a reevaluation of sciences in the eyes of adolescents, who often slide along the comfortable slope of certain humanistic areas, in which they wind up by the process of elimination. (One often hears the argument, “I’m studying law because it doesn’t have mathematics.”) Further, above all those considerations, the most important thing is to create thinking minds, the minds of free people.
ST Carinae, An Algol-Type System in a Possible State of Rapid Mass Exchange
Authors: Chambliss C.R. , Walker R.L.
Published: July 2016

ST Carinae is an eclipsing binary with a period of 0.90165 days and is believed to consist of an A0 V primary and a secondary of type F5 - 8 IV. About 900 observations in UBV, made by Somerville in 1963, but unreduced at that time, are analyzed with the Wood Model. These are also compared with the solutions obtained by previous investigators of this system. The solutions indicate a reasonably consistent geometry, but there is still substantial uncertainty with regard to the mass-ratio and dynamical status of the system. The possibility exists that ST CAR is in the initial and rapid stage of mass exchange in which the primary component fills its Roche lobe and is losing mass to its companion. The two components of ST CAR appear to be of normal dimensions, but additional work is needed to clarify the exact status of this system. It is planned that a re-analysis using the Simplex program will clarify the dynamical status of ST CAR.