bluuebunny/crossref_metadata_2025_split huggingface dataset:
Origin and Evolution
Authors: Savedoff Malcolm P. 
Published: July 2016

Discussants have been asked to synthesize and prophecy rather than to summarize. The variety of models and views expressed here warn that any report is only another opinion. Blessing to the reader.The major impression from these sessions is a general discontent with simple qualitative answers while encouraging more realistic exploration of both theoretical and observational questions. Let us examine some of the major questions raised.
Study of an active region of the Sun during three rotation periods
Authors: Macris Constantin J. , Prokakis T. J. 
Published: July 2016

The abnormal evolution of an active region during three solar rotations is studied. The high density of flares during the second and third rotation seems to be caused by the collision of new active centres with existing ones.The increase of the activity is probably due to the disturbance of the magnetic field which became more complex because of the appearance of new centres near the original one.
Étude critique d'un champ ‘current-free’ dans l'atmosphère solaire
Authors: Rayrole J. , Semel M. 
Published: July 2016

To test the validity of the assumption of a ‘current-free’ magnetic field in the atmosphere above sunspots, we measured all three parameters of the magnetic field in an active region and compared it with the calculated current-free field according to the solution proposed by Schmidt. We found important differences between the calculated and the measured field.We refer to an earlier paper where the objections to the ‘current-free field’ were that the calculated field has too simple a configuration to account for the fine structure observed in Hα and other solar observations.
The connection of fine-structure photospheric features in active regions with magnetic fields
Authors: Steshenko N. V. 
Published: July 2016

1.The fine structure of the proton sunspot group of July 4–8, 1966 was studied on the basis of high-resolution heliograms. The comparison of the orientation between penumbral filaments and the transverse magnetic fields (observed by A.B. Severny and T.T. Tsap) shows that the direction of the filaments coincides in general with that of the magnetic field.2.Measurements of the magnetic fields of smallest pores (1·5″-2″) showed that the pores are always connected with strong magnetic field (in average 1400 gauss), which is localized at the same small area as the pore.3.Magnetic fields of faculae are concentrated in small elements with the dimension not exceeding 1·5″-3″. Magnetic-field strength H|| of about 45% of facular granules is within the limits of photographic measuring errors (approximately 25 gauss). For a quarter of all facular granules the strength H|| is from 25–50 gauss; about 30% of facular granules have H|| > 50 gauss, and sometimes there appear faculae with field strength of about 200 gauss. The magnetic-field strength of facular granules, which are found directly above spots, is 10–20 times less than the field strength of spots. This field is 80–210 gauss only.4.All observational data mentioned above show that the appearance of the fine-structure features in active regions is directly connected with the fine structure of magnetic field of different strength and different orientation. The study of high-resolution heliograms gives additional information about the fine structure of the magnetic field.
On some aspects of XUV spectroheliograms
Authors: Tousey R. , Sandlin G. D. , Purcell J. D. 
Published: July 2016

A comparison between XUV and Ca-K spectroheliograms for 9 dates from 1963 to 1967 showed an excellent correlation between plage intensities in Ca-K and He II 304 Å, except for plages near the limb and a few others. Around the limb all but the highest ionization XUV emission lines form a bright ring, usually weaker over the poles. This is an unresolved combination of the limb-brightened emission from the quiet corona and high chromosphere, and emission extending into the corona above plages located as much as several days from limb passage.In Fe XV and XVI only the localized coronal emissions are observed; these vary in form and intensity from line to line. The 171–500 Å and white-light coronas, recorded on November 12, 1966, correlate well at low altitudes, but beyond 3′ the XUV corona becomes diffuse and without structure.
Interaction of magnetic fields and the origin of proton flares
Authors: Křivský L. 
Published: July 2016

The magnetic model of a proton flare is discussed, in agreement with the known characteristic features of proton-flare development, on the basis of the interaction of an emerging magnetic channel from the photosphere, and its being wedged into the field of an already existing interaction of two systems of magnetic fields of a complex active region with spots. This explains the origin of the two emission filaments following the splitting and of the ‘annular’ emission filament, entering the corona, connected by a fine loop structure with two split filaments in the chromosphere. The acceleration of particles and their ejection will take place in a number of created ‘zero line’ spaces and in spaces where magnetic lines of force are reconnected.An attempt is made to explain some Hα phenomena in connection with proton flares, by means of interactions of magnetic fields in the chromosphere and in the lower corona.
Some results on solar activity at 408 MHz
Authors: Clavelier B. 
Published: July 2016

We present the first results obtained with the 408 MHz interferometer of Nançay. The typical activity observed at 408 MHz is the ‘noise storm’. Undoubtedly with this apparatus we could distinguish multiple centres, generally double.The comparison with corresponding optical observations and with Nançay observations at frequency 169 MHz allowed us to associate the centres of noise storm at 408 MHz with eruptive centres lying in ‘Anomalous Active Regions’ and to describe the schematical structure of active zones.
The X-Ray Corona and the Photospheric Magnetic Field
Authors: Krieger A. S. , Vaiana G. S. , Van Speybroeck L. P. 
Published: July 2016

Soft X-ray (3–60 Å) photographs of the solar corona have been obtained on four flights of a rocket-borne grazing incidence telescope having a resolution of a few arc seconds. The configuration of the X-ray emitting structures in the corona has been compared to the magnetic field distribution measured by photospheric longitudinal magnetograms. The X-ray structures trace the three dimensional configuration of the magnetic field through the lower corona.Active regions in the corona take the form of tubular structures connecting regions of opposite magnetic polarity within the same or adjacent chromospheric active regions.Higher, larger structures link widely separated active regions into complexes of activity covering substantial fractions of the disk. The complexes are separated by areas of low average field in the photosphere. Interconnections across the solar equator appear to originate over areas of preceding polarity.Enhanced X-ray emission is observed, outside the active belt, over areas of enhanced general magnetic field. Bright point-like X-ray features are observed above bipolar areas in the general coronal field.Two, probably related, classes of X-ray features are associated with points of high field gradient along the longitudinal magnetic, ‘neutral line’. Both in the non-flaring active region and in flares the brightest emission is observed from one or more small line sources (at our present resolution). In flares this can account for a substantial fraction of the total soft X-ray emission of the flare.
Evidence for Non-Velocity Redshifts-New Evidence and Review
Authors: Arp Halton 
Published: July 2016

Evidence for non-velocity redshifts in quasars and galaxies is reviewed. It is shown that all current statistical tests favour the association of at least some quasars with relatively nearby galaxies. It is shown that a statistically significant number of quasars falling close to faint galaxies have intermediate redshift (between z = 0.4 and 1.8). This confirms the previous result that those are the intrinsically most luminous quasars and keeps open the possibility that less luminous quasars can appear projected at large distances around very nearby galaxies.It is shown that in four individual cases where quasars fall, projected, closest to bright galaxies, the galaxies show evidence of physical interaction. New evidence for perturbations of the inner isophotes of NGC 4319 by Markarian 205 and by a radio source on the opposite side is presented.Evidence for systematically higher redshifts for compact and peculiar companion galaxies is reviewed. The intrinsic redshift-morphology relation for clusters of galaxies is commented upon and the relation to Tifft's work is noted. As a summarizing diagram, the individual associations of high redshift quasars and companions are used to show an empirical continuity of observed characteristics between compactness (taken to be a measure of youth) and excess redshift.Finally some possible theoretical explanations for intrinsic redshifts are mentioned.
Radio Frequency Observations of the Nuclei of Galaxies
Authors: Ekers R. D. 
Published: July 2016

For spiral galaxies the nuclear radio emission is usually dominated by a complex distribution of emission with median diameter of 200 pc and median power of 1019 W Hz−1 sr−1 at 1400 MHz. There is a large range in both power and diameter. The power is independent of morphological type for the normal spirals but is correlated with the absolute optical magnitude and with the infrared emission. For Seyfert galaxies the emission is generally stronger, in some cases by several orders of magnitude (e.g. NGC 1275, 3C 120).Elliptical galaxies have been found with very compact radio sources, some less than a parsec in diameter. These are as powerful as the strongest spirals (~ 1021 W Hz−1 sr−1). Even stronger compact nuclear sources are now being found in the nuclei of those elliptical galaxies which also have extended radio sources (the radio galaxies). The presence of nuclear sources of this strength is so highly correlated with the presence of extended sources that this suggests a continuing involvement of the nucleus.
Profondeur de penetration et formation des raies dans une atmosphere diffusante
Authors: Fouquart Y. 
Published: July 2016

The systematic study of the distribution of the photon optical path in a finite scattering atmosphere gives the penetration depth of the radiation in a cloud; one can get then an accurate knowledge about the layer thickness in which the spectral line has been formed. The relation between the observed line frequency and the corresponding altitude is thus precisely expressed. The method is presented here with some preliminary results, it could be applied to the Venus, Jupiter and Saturne atmospheres to improve the knowledge of their clouds internal structure.Using this method in case of Venus spectral lines it has been possible to deduce that for the Hansen's model, the optical depth of Venus clouds should be of the order of 40 and the cloud top closed to 70 km height.
Millisecond Polarized Pulses in Decametre-Wave Radiation from Jupiter and Sun
Authors: Barrow C. H. 
Published: July 2016

A new approach is suggested to the problem of the theory of Jovian decametric radiation and physical conditions at the point of origin. This depends upon a comparison of the characteristics of fast pulse decametre-wave radio emission from both Jupiter and the Sun and invokes the deductive procedure which Sagan (1971) has called ‘Propositional Calculus’.Fast polarized pulses in radiation from Jupiter and the Sun have been studied at fixed frequencies in the range 18 to 26 MHz with time resolutions from one to five msec; a number of similarities between the pulses from both sources have been noted. A comparison of some of the pulse characteristics is being made in order to decide whether or not they are sufficiently alike to be regarded as having a common mechanism of origin at both Jupiter and the Sun. From this ‘decision’ it is proposed to establish boundary conditions for theoretical study. Fast pulses in the Jupiter radiation are generally supposed to be a source phenomenon although their actual mechanism is not understood. The reasons for this are to some extent inferred rather than proven and so, to check the possible (if unlikely) role of the interplanetary medium, observations are also being made using the large 26 MHz array at the University of Florida to search for possible fast pulses in the radiation from the more distant source Taurus A.
Radio Observations of IR/OH/H2O Stars
Authors: Caswell J. L. 
Published: July 2016

A small percentage of infrared stars, selected on the basis of their IR brightness at 2.2 µm and their redness (I–K colour index), show 18 cm OH emission, and some exhibit 1.35 cm H2O emission; further investigations identify some of these objects as M-type supergiants and the remainder as M-type giant long-period variable stars.For the strongest 1612 MHz OH emitters, long-baseline interferometry shows that the emission arises from a large number of small-diameter features distributed over a much larger, approximately elliptical region corresponding to a circumstellar cloud. Models for the geometry of the emitting regions are discussed.The OH characteristics with respect to the ratios of line intensities for different transitions and the velocity structure are distinctive, not being found in other types of OH source; consequently a large number of new OH emitters can be recognized as probably IR/OH objects despite the absence of IR or optical data; the precise classification of these sources is considered together with their relevance in understanding the identified sources.
The Infrared Properties of Circumstellar OH/IR and H2O/IR Sources
Authors: Caswell J. L. 
Published: July 2016

Anomalous OH and H2O microwave emission is a common occurrence in circumstellar shells surrounding cool oxygen-rich M supergiants and Mira variables. Infrared spectra have shown that the atmospheric conditions in these stars are such that the concentration of OH molecules is a maximum. For those with H20 microwave emission, strong H20 1.9 μm absorption is present.There exists a growing number of typical OH/IR sources discovered by radio surveys, for which no associated IR object has yet been found. Preliminary results of TV photography to discover IR counterparts are shown.Several interesting correlations have been defined between the IR colour, period and amplitude of infrared variability, and the velocity separation of the OH emission peaks. The relationship of these to pulsationally driven mass loss and the observed characteristics of circumstellar dust shells is investigated.The maser emission from OH/IR and H20 / I R sources is believed to be pumped by IR radiation. Combined studies of the variability of OH and H20 emission and the IR continuum of the Mira sources confirm that IR pumping is probably the dominant mechanism, although the data do not appear to favour any specific pump scheme. The OH masers are at least partially saturated; the degree of saturation of the H20 masers is unclear.
Continuum Radio Emission and Galactic Structure
Authors: Price R. M. 
Published: July 2016

Recent studies of high latitude brightness have shown that in several regions a significant proportion of it is due to loop features. The largest of these are now thought to be local (within a few hundred parsecs) and perhaps to be due to supernova events.Aperture synthesis maps of 45 external spiral galaxies have shown large-scale continuum nonthermal features in the disks of some and, in general, an absence of spherical halos around the galaxies. This supports the view that the radio emission from our Galaxy can best be described as coming from a thick disk. Any large-scale spherical component could not have a volume emissivity greater than 1.5% of the average volume emissivity of the disk at meter wavelengths.A comparison of the disk radiation with new disk models suggests that the galactic plane radiation has two components: a base disk and a spiral component. Each of these contributes ~50% of the total power output of the disk at 150 MHz.
On the Chemical Abundances, Evolutionary Stage and Bolometric Magnitude of WR Stars
Authors: Vanbeveren D. 
Published: July 2016

I will comment on 3 problems concerning WR stars:
a.are WR stars core hydrogen/core helium burning?b.are WR stars H-poor or do they have normal abundances?c.can we use B.C. for WR stars which are similar as for 0 stars?
A New Search for Nebulae Surrounding Wolf-Rayet Stars
Authors: Heckathorn Joy N. , Bruhweiler Frederick C. , Gull Theodore R. 
Published: July 2016

We have used the plate data from An Emission Line Survey of the Milky Way by Parker, Gull and Kirschner(1979) to make a new search for ring nebulae around Wolf-Rayet stars. The Survey consists of narrow-band interference filter direct imagery centered on the emission lines of Hα + [N II] at λ6570, [O III] at λ5007, and [S II] at λ6730. We have discovered at least five new ring nebulae. of the fifteen ring nebulae we were able to detect on the Survey, including our new discoveries, eleven were brighter in the [O III] bandpass than in the Hα + [N II] bandpass, and were filamentary in [O III]. All of the nebulosities we were able to detect were rated on the basis of three criteria:
1)Sharp, filamentary structure present in any or all bandpasses.2)Wolf-Rayet star centered in projected nebulosity, or, if off-center, the segment of the ring nearest the star proportionally brighter than the rest of the ring.3)Absence of any O stars within the nebulosity, or O star in off-centered position not adjacent to the brightest or sharpest portion of the ring.
An Improved Polar Motion and Earth Rotation Monitoring Service Using Radio Interferometry
Authors: Carter William E. , Robertson Douglas S. , Abell Michael D. 
Published: July 2016

The National Geodetic Survey (NGS) of the National Ocean Survey (NOS), a component of the National Oceanic and Atmospheric Administration has begun a project to establish and operate a 3-station network of permanent observatories to monitor polar-motion and Earth rotation (UT1) by radio interferometric observations of quasars. The project designation is POLARIS (POLar-motion Analysis by Radio Interferometric Surveying).The POLARIS observatories will be equipped with a new generation of instrumentation and software, the Mark III data acquisition and processing system currently under development by a multi-organizational team.
Observation de la Raie Hα dans les Etoiles Be
Authors: Andrillat Y. , Fehrenbach Ch. 
Published: July 2016

Few studies concern the H alpha profile of the Be stars and it is difficult to do a fine analysis of the line structure, and of its variations from the results obtained with different resolutions and accuracies.Then, it was useful to apply modern technics for the observation of this line to get an homogeneous material, sensitive enough to show fast variations of the order of few minutes because an accurate photometry is available using linear response receivers.
Meteoroid Streams
Authors: Steel Duncan 
Published: July 2016

Meteoroid streams, producing meteor showers if some part of the stream has a node near 1 AU, have complex structures which are only just beginning to be understood. The old simplistic idea of a narrow loop being formed about the orbit of a parent comet with one, or possibly two, terrestrial intersection(s) is now being replaced by the recognition that their dynamical evolution may render convoluted and distorted ribbon shapes with eight or more distinct showers being generated. As such the streams are excellent tracers of the sorts of orbital evolution which may be undergone by larger objects (asteroids and comets) in the inner solar system; indeed it is now known that objects presently observed as Apollo-type asteroids may also be the progenitors of streams.Searches for showers associated with newly-discovered possible parent objects may be carried out either via the calculation of theoretical meteor radiants (which have hitherto been derived using an untenable method), or through searches of catalogues of individual meteor orbits. In order to accomplish the latter, about 68,000 radar, photographic and TV meteor orbits from various programmes in the U.S.A., the former Soviet Union, Canada and Australia are available from the IAU Meteor Data Center, and more than 350,000 orbits of very faint meteors have been determined over the past three years using a new facility in New Zealand.The discovery amongst IRAS data of dust trails lagging behind comets has opened up a new way in which meteoroid streams may be investigated, although the relationship between these trails and the streams observed as meteor showers at the Earth is by no means clear at this stage. Similarly radar, radio and spacecraft impact observations of meteoroids near cometary nuclei have added to our knowledge.In spite of the improvement in our understanding of meteoroid streams over the past few years it is clear that there is much still to be done. The words of W.F. Denning in 1923 are still pertinent: “Few astronomers occupy themselves with the observation and investigation of meteors, and yet it is an attractive field of work offering inviting prospects of new discoveries”.
Dust Particles and Molecules in the Extended Atmospheres of Carbon Stars
Authors: Gilra Daya P. 
Published: July 2016

It is shown that the absorption due to a circumstellar shell containing solid silicon carbide particles can very nicely explain the observed strong violet opacity in stars in which the carbon to oxygen ratio is > 1. It has been shown by Friedemann and Gilman that solid SiC particles can form in the cooler outer layers of such stars. Thermal re-emission from SiC particles is predicted to be in the 10–13 μ region and recent infrared observations by Hackwell show an emission band in this region, thereby strongly supporting the SiC suggestion. It is also shown that the opacity due to C3 pseudo-continuum is not adequate to explain the observed violet opacity.It is suggested that the vibrational bands of C3 and SiC2 molecules should be among the major opacity sources in the infrared spectra of the late N-type carbon stars and some of the observed bands may be, at least in part, due to these molecules. The frequencies of their isotopic species have been calculated and attempts should be made to observe these bands.Thus the atmosphere of a late N-star should be pictured as containing, probably on its outskirts, solid carbon particles. There is some kind of smoke veil around the star causing a reddening by absorption of the ultraviolet.A veiling effect by smoke has been occasionally envisaged to interpret various astronomical phenomena, even in the case of novae. A late N-star would be a striking example. The smoke veil would vary in variable N-stars.B. Rosen and P. Swings (1953)
Observational asteroseismology of δ Scuti stars
Authors: Breger M. , Audard N. 
Published: July 2016

Ground-based observational networks are now able to reliably detect more than 20 frequencies for individual δ Scuti stars. The ground-based Delta Scuti Network specializes in the intensive study of individual stars for several months with dedicated telescopes on different continents. With the new quantity and quality of data, the observational limit to extracting 50 or more frequencies in a single δ Scuti star is no longer determined only by the signal/noise ratio, but by the available frequency resolution.Recent results on the δ Scuti stars FG Vir and 4CVn are presented. 4CVn exhibits some of the characteristics of δ Scuti stars: some close spacings are observed, pulsations occur in specific frequency regions with relatively sharp borders, and show large amplitude variations. This presents an important asteroseismological diagnostic, and can help us to improve our understanding of for example rotation and excitation mechanisms.We also report a new Gamma Doradus variable with two excited g modes (HD 108100, F2V).