bluuebunny/crossref_metadata_2025 huggingface dataset:
Survey of Data for Determining Scales of the Absolute Flux Densities in 10-180 MHz Range and Source Spectra in the Declination Strip 10° − 20°
Authors: Braude S. Ya.
Published: July 2016

To determine the frequency spectra of radio sources the flux densities of these sources should be measured at the widest possible frequency range. The use of different telescope types, methods of measurements and calibrations led in a number of cases to the considerable difference in the data of various observatories. At the present time for frequencies above 400 MHz the scales of flux densities - S for - S ≥ 1 Jy = 10−26w m−2Hz−1 presented by different authors coincide accurate to 5%. Up to now for frequencies below 200 MHz a single scale of fluxes recognized by all radioastronomers is absent. We attempted to determine such a scale for frequencies 180-10 MHz. We used both analysis of the published data and the results of the new measurements obtained with the UTR-2 Radiotelescope in the declination strip 10° – 20° at frequencies 10.0; 12.6; 14.7; 16.7; 20, and 25 MHz. The method of these measurements and the obtained results are described in detail in [1]. The UTR-2 Radiotelescope has 5 beams in declination with half power beam width in a zenith direction 20′ × 20′ at 25 MHz [2]. The absolute values of the flux densities of all observed discrete radio sources are defined during the experiments. Minimum flux density measured at frequency 25 MHz – 15-20 Jy, with a signal-to-noise ratio equal to 3-4. During measurements about 300 radio sources were found. Comparing these data with our earlier measurements obtained with the UTR-1 Telescope [3] as well as with corrected data of the both Pentincton [4] at 10.02 and 22.25 MHz and the Clark-Lake Observatories at 26.3 MHz [5] and the results obtained in Cambridge at 38 MHz [6] and 178 MHz [7, 8] we have derived some correcting factors allowing to bring the data of different catalogues to a single scale. The method for determining such factors is described in [9]. It was shown that below 200 MHz where the influence of ionosphere is great, it is necessary to take into account two corrections : regular scale shift of the one catalogue to another z12 = 1/z21 (1/z21 is the average value of the relation between flux densities of the first catalogue and the second one) and a scale shift caused by the multiplicative scatter. A value is greater than unity and it can be determined comparing with each other three different catalogues. The comparison results of a number of catalogues with data obtained with UTR-2 are shown in table I.
The Parkes 2700 MHz Survey: Counts of the Sources and their Distribution on the Sky
Authors: Wall J. V.
Published: July 2016

The Parkes 2700-MHz survey for extragalactic sources now extends over virtually the whole sky available to the 64-m telescope at galactic latitudes |b| > 10°. Eleven parts of the catalogue have been published as Astrophysical Supplements of the Aust. J. Phys. (Numbers 19, 21, 26, 30, 32, 34, and 39); part 11 and subsequent parts consist of re-surveys of some areas to fainter flux density limits. The current version of the composite catalogue for the 7.36 sr covered (Fig. 1) contains about 7500 sources, together with the results of identification programmes and flux density measurements at other frequencies.
Radio Source Angular Sizes and Cosmology
Authors: Ekers R. D. , Miley G. K.
Published: July 2016

The main cosmological tests using radio sources as probes are summarized below.
The Angular Diameter-Redshift Test for Large Redshift Quasars
Authors: Riley J. M. , Longair M. S. , Hooley A.
Published: July 2016

Complete samples of quasars in the 3CR and 4C catalogues have been observed with a resolution of 2″ arc in RA and 2″ cosecδ in dec with the Cambridge 5-km telescope at 5 GHz (Riley & Pooley 1975; Jenkins et al 1977), from which it has been possible to determine the overall angular sizes of their radio structures (LAS). The angular diameter-redshift test for quasars has been reexamined using these data; details are described fully elsewhere (Hooley et al 1977).
Luminosity Functions for Extra Galactic Radio Sources
Authors: Fanti R. , Perola G. C.
Published: July 2016

The monochromatic luminosity function of radio sources (RLF) is the number of sources per unit volume as a function of the luminosity P at a frequency v and of the cosmic epoch (z). Symbol : n(P(v),z). It is often given per interval of log P, or Mr, the absolute radio magnitude. This function is determined only for sources associated with optical objects (galaxies and QSO's). It can be given for all kinds of associations, or for sources associated with a specific type of object. In this case the normalized, or fractional, RLF is sometimes used, Fi (P,z) = ni (P,z)/ρi (z), where ρi is the space density of type i objects. The word “bivariate” is used for the RLF defined per interval of the optical luminosity (or magnitude M). A RLF can be determined using either a radio–optically complete sample of identified sources, or the radio observation of an optically selected sample. The merits of methods used to estimate a RLF from a complete sample are discussed by Felten (1976). Translation of a RLF from one frequency to another must be done with care if, at the two frequencies, different radio components (like the extended and the compact) would be preferentially sampled. We shall review the estimates of local (z = 0) RLF's using Ho = 100 Kms−1 Mpc−1 and the unit WHz−1 for P.
The Redshift-Magnitude Relation for Radio Galaxies
Authors: Smith Harding E.
Published: July 2016

We examine the Hubble diagram for radio galaxies and compare radio galaxies and first-ranked cluster galaxies as cosmological test objects. Radio source identification programs are now producing reliable identifications with galaxies as faint as V ≈ 23 and spectroscopy of these objects has already resulted in the discovery of galaxies with redshifts as high as 0.75, thus there are great expectations for progress in the near future. As in the past, indeterminate corrections, notably luminosity evolution and a possible correlation between radio power and optical luminosity, preclude the determination of qo.
Fluctuations in the Microwave Background Caused by Anisotropy of the Universe and Gravitational Waves
Authors: Novikov I. D.
Published: July 2016

The problem described in the title has already been theoretically analysed several times (see for example Dautcourt, 1969 and Novikov, 1974). Recently, however some important new aspects of the problem have been discovered; they are discussed briefly in this report which is based upon the calculations of Doroshkevich, Lukash, Novikov and Polnarev. First consider the influence of primordial gravitational waves on the microwave background. It is natural to assume that in the Universe, in addition to acoustic (or adiabatic) density perturbations which result in galaxy formation and corresponding metric perturbations, there also exist metric perturbations in the form of gravitational waves with wavelengths of the same order of magnitude as the acoustic perturbations. The amplitude of such gravitational waves could in principle be quite arbitrary. Their amplitude can be estimated by comparing the theory of such waves in the expanding Universe with the observed fluctuations in the microwave background which are now available or will be in future.
Young Galaxies, Quasars and the Cosmological Evolution of Extragalactic Radio Sources
Authors: Longair M. S. , Sunyaev R. A.
Published: July 2016

The V/Vmax test for quasars and the counts of radio sources show that the most powerful extragalactic radio sources exhibit strong evolutionary changes with cosmological epoch (see M. Schmidt and J.V. Wall et al., this volume). It should be emphasised that these are very large changes indeed. Schmidt, for example, has shown that for the world model with Ω = 0, evolution functions of the form F(t)∝exp(-10t/to) can account for the observations, to being the present epoch and t cosmic time. Since the quasar population from which this law is derived extends at least to Z = 2.5, corresponding to t = to/3.5 if Ω = 0, the comoving space density of quasars at Z = 2.5 must have been about 1300 times greater than it is at the present epoch. It is not known whether or not this law continues to hold at larger redshifts but even if it does, the increase in comoving space density from Z = 2.5 to infinity is only a further factor of 17. Therefore the bulk of the evolution occurs within the range of observationally accessible redshifts. Notice that a characteristic time-scale for the decay of the quasar population of ≈ to/10 ≈ 109 years comes out of this analysis.
Polarization Measurements of Distant Sources
Authors: Conway R. G.
Published: July 2016

Polarization measurements, in addition to their interest for deciphering the internal physics of radio sources, are relevant to cosmology because estimates of ne, the thermal electron density, may be obtained from measurements of the Faraday effect. We have:-
Cosmological Information from New Types of Radio Observations
Authors: Saslaw William C.
Published: July 2016

To have squeezed the Universe into a ball

To roll it toward some overwhelming question.

T. S. Eliot

So far, we have mainly discussed what might be called classical methods for investigating cosmological models using radio observations. These mostly involve the number counts as a function of measured flux, angular diameters, and spatial distribution of radio sources at cosmological distances, as well as the measurements of the microwave background. In this review, I have been asked to give a brief description of some new, or non-classical, measurements that might be made. It seems that such measurements fall into one of three categories: Observations which are being made now and which may bear fruit in the next several years, observations which may be possible in the intermediate future several decades from now, and observations which may be possible in the far future - if ever. Naturally I'll try to concentrate on the first two categories since they will be of more interest to most living astronomers during their working lifetimes. Also, since time is short and it is very difficult to predict the future, I'm afraid that this review will be somewhat impressionistic rather than exhaustive. I hope people will describe additional methods during the discussion.
Nuclear Reactions and Neutrinos in Stellar Evolution
Authors: Arnett W. David
Published: July 2016

Much of the material discussed in this review represents a summary of some chapters in a monograph I am writing (Arnett, 1974); a more detailed discussion will be found there.
Observational Data on Novae and Supernovae
Authors: Mustel E. R.
Published: July 2016

The first half of the paper contains a discussion of the chemical composition of the envelopes of supernovae for the period close to light maximum. The principal conclusions are: The abundance of hydrogen in the envelopes of type I supernovae is low, much lower than that of nitrogen; the abundance of oxygen and carbon is also noticeably lower than that of nitrogen; it seems that there is plenty of helium and metals in these envelopes. The information for type II supernovae is more limited. But it is quite certain that the abundance of hydrogen in the envelopes of these stars is much higher than in the envelopes of type I supernovae.

In the second half of the paper the problem of supernova remnants is discussed, the circumstellar shells around supernovae (which according to S. van den Bergh and M. Peimbert are ejected from the star before its explosion) are also included. The discussion of this problem permits to confirm again the idea that there is a very close similarity between supernovae and novae. To be more exact there are reasons to suggest that supernovae as well as novae are double star systems, that they are relatively ‘old’, that they are quite peculiar objects and that they are not the final stage of evolution of ‘normal’ stars.
Instability in Stars of Early Spectral Type
Authors: Struve Otto
Published: July 2016

This paper consists of two parts which, at first sight, are quite detached from each other: the pulsating variables of spectral types B to F, and the close spectroscopic binaries of the types of β Lyrae, UX Monocerotis and U Cephei. I shall show that there exists a connexion between these groups which, though still rather nebulous (in both senses of this word), promises to yield interesting results.
The Stars with Double Envelopes
Authors: Tsesevich V. P.
Published: July 2016

In modern astronomy we acquire fundamental knowledge concerning the dimensions and the constitution of the exterior layers of giant stars by the study of eclipsing systems. The red giants which form part of the systems of VV Cephei and ζ Aurigae have been studied thoroughly from the changes that the spectra of these systems undergo when the light of the bright eclipsed star passes through the envelope of the rarefied giant. At the present time it is clear that stars having extended envelopes are not rare. Thus, for example, F. I. Loukatskaya[1] (at the Principal Astronomical Observatory of the Academy of Sciences of the Ukrainian S.S.R.) has studied the eclipsing star AW Pegasi in different parts of the spectrum; she has shown that this star possesses a semi-transparent envelope that produces a considerable part of the eclipse. It turns out besides that certain spectral lines, observed in the spectrum of the bright star, come from the semi-transparent envelope of the less luminous companion.
E. Radiative Control of Flow Problems in Aerodynamics
Authors: Goulard R.
Published: July 2016

Thomas:In the preceding four sessions, we have considered the aerodynamic flow problems involved in the pulsating variable stars. We have been particularly interested in the question of radiative control of the flow through radiative control of the internal energy state of the gas. If I abstract the overall discussion thus far, especially the contributions of Whitney and Oke, the argument is that the state of at least the observable regions of the atmosphere is the same as it would be if those regions belonged to a nonpulsating star having the same radiative flux and effective gravity. That is, in the pulsating star, the energy transfer situation finds at each phase some radiative flux, the manner of whose production is irrelevant for the present argument, but to which the internal energy state of the atmosphere adjusts in a time short compared with any time-variation of the flux or the flow-pattern relaxation time. Then, except for the pattern of spectral line-displacements accompanying the motion, the observed spectrum is fixed by this internal energy, which is fixed by the radiative flux. The dynamical effects of the pulsation fix the effective gravity. There is possibly a perturbation on this simple picture in the atmospheric regions where the shock happens to be; and Kraft suggests that in the outer atmospheric regions the variable and non-variable star differ because of the direct and indirect effects of an increased ‘turbulence’ generated by the pulsation.
E. Radiative Transfer in Turbulent Atmospheres: The Diagnostic Problem
Authors: Rybicki G. B.
Published: July 2016

One easily observed violation of the classical assumptions of stellar atmosphere theory is the presence of the horizontal inhomogeneities on the solar surface. There are many forms of these inhomogeneities, some clearly connected with the underlying convection zone, and others whose origins are not as yet understood. The most outstanding of these, perhaps, is the solar granulation, which appears as a fairly random pattern on high resolution photographs of the Sun.
The Polar Motion Derived from Both Time and Latitude Observations
Authors: Takagi Sigetugu
Published: July 2016

The coordinates of the pole were derived from both time and latitude observations made at eight observatories from 1962 to 1964. The differences between these results and the ILS results show an annual variation. After removal of this term the standard deviation is about ±0′′.03 for the x- and y-components. Corrections to the adopted longitudes and latitudes are obtained and these agree closely with those obtained by the BIH.
Intercontinental Longitude Differences of Tracking Stations as Determined from Radio-Tracking Data
Authors: Trask Donald W. , Vegos Charles J.
Published: July 2016

Radio tracking of artificial satellites has provided longitude differences between stations on different continents to 10 m. An accuracy of 1 m in the future is expected.
21. The separation of small particles from meteor bodies, and its influence on some parameters of meteors
Authors: Simonenko A. N.
Published: July 2016

The separation of very small particles from meteor bodies as a part of the process of their ablation in the Earth's atmosphere is assumed by many investigators. But when the particle is small relative to the meteor body the path of the particle is a priori thought to be small relative to the length of the meteor path, i.e. the particle is expected to evaporate in close proximity to the point of separation. This assumption is not acceptable after McCrosky's work (1958) that has shown for one particular case the small particles (m = 10−5−10−6 g) go a long path before their mass is exhausted. The assumption made until now has caused incorrect conclusions, e.g. the luminosity at any point of the meteor path is proportional to the mass ablated from the meteor body at that point (Kramer, 1965).
26. The flux of meteors and micrometeoroids in the neighborhood of the earth
Authors: Nilsson C. S. , Southworth R. B.
Published: July 2016

1. Radio meteor rates for a calculated mass range 10−6 gm to 10−4 gm have been recorded semi-continuously at Havana, Ill., since July 1965. Automatic equipment samples the rate at four different levels of sensitivity each half hour. A flux vs. mass power law has been derived from these data for each of a number of different weeks of observation. Between September 1965 and December 1966 the mean cumulative influx I of meteors/m2/sec/2π ster can best be described by the equation:

where m is the lower mass limit in grams.

2. A micrometeoroid detection system, which hopefully was to have measured particle velocities and directions of arrival for masses greater than 10−12 gm, has been flown on the OGO-II satellite. A comprehensive in-flight calibration system has confirmed the correct operation of the experiment for more than one year in space. 700 hours of data have been analyzed and no micrometeoroid events have been observed. This excludes several hundred spurious events from the microphone sensors. The effective detection area of the instrument is 0·8 cm2 ster. Thus, to a probability of 0·86, the average flux of particles of mass greater than 10−12 gm must be less than 6 × 10−2 particles/m2/sec/2π ster.
29. A note on the sporadic meteor radiant distribution
Authors: Třísková L.
Published: July 2016

Some results concerning the sporadic radiant distribution – or rather the sporadic radiant efficiency – obtained from meteor forward-scatter data are presented.
47. Collisional model of asteroids and their debris
Authors: Dohnanyi J. S.
Published: July 2016

A collisional model for interplanetary debris, formulated earlier by the writer, is applied presently to the problem of asteroids and their debris. Following observational evidence, a population-index type-number density function is assumed. The integro-differential equation describing the evolution of a system of colliding brittle particles derived earlier is satisfied for this special case. The result is a stable steady state solution subject to certain boundary conditions. It is found that catastrophic collisions dominate over the erosion process in the present steady state model.

Using a root mean-squared average collision velocity of 5 km/sec, the population index, α, for asteroids is calculated to be α = 1·837. This value of α is rather insensitive to the physical parameters and is within the margin of error of an empirical least squares fit by the writer α = 1·80 ± ·04 to the distribution of asteroids reported by Kuiper et al. If the largest three asteroids are statistically interpreted, the distribution of asteroids in the asteroidal belt is consistent with the present collisional model. This would imply that most asteroids are fragments from some parent object(s).

The theoretical distribution is normalized to the observed number of asteroids in the survey by Kuiper et al., and using the present theory various statistical properties of the population of asteroids and their debris are calculated. The total mass of objects in the asteroidal belt is almost entirely concentrated in the masses of the three largest objects. The total asteroidal mass, crushed yearly, is of the order of 1012 kg and the rate of mass loss to radiation forces is about 7 × 1010 kg/yr.

The mean lifetime of large asteroids is found to be of the order of 108–109 years. The lifetime of objects is limited by the probability of catastrophic collisions; erosion and radiation damping only have a minor influence on the particle lifetimes.

The erosion rate of the largest objects is of the order of 1m /106 yr, and this rate decreases for smaller objects. Comparison with erosion rates estimated by Whipple indicates that the lifetimes, with respect to erosion, of objects smaller than about 1 kg may be dominated by collisions with cometary particles.
Planetary Nebulae in the Magellanic Clouds
Authors: Westerlund Bengt E.
Published: July 2016

The available photometric and spectroscopic data on the planetary nebulae in the Magellanic Clouds are discussed. Recent results regarding the distribution of the planetary nebulae in the Clouds and the kinematics of the Clouds are presented. Masses are determined for selected planetary nebulae in the Clouds, and the question about the most likely average mass is considered. The evolutionary tracks of the nuclei for two values of the average mass are compared with the actual positions in the HR diagram of the nuclei of the planetary nebulae in the Clouds.
A Preliminary Report of a Survey of Planetary Nebulae in the Southern Hemisphere
Authors: The Pik-Sin
Published: July 2016

As you know, the new and most complete catalogue of galactic planetary nebulae, compiled by Perek and Kohoutek, has recently been published. This catalogue will certainly be very useful for astronomers working on planetary nebulae.
Observed Angular Motions in Planetary Nebulae
Authors: Liller Martha H. , Liller William
Published: July 2016

Plates of planetary nebulae taken in October 1965 and June 1967 with the 100-inch and 60-inch telescopes on Mount Wilson are compared with photographs taken with the same instruments 40 or more years previously, to determine the amount of angular motion of material outward from the central stars. Densitometer tracings of the nebulae yield values of , the radial motion in seconds of arc per century for condensations (filaments, rings, etc.) as well as for the edges of the visible material. Preliminary data are presented for NGC 2392, 6818 and 7662. For NGC 2392 and NGC 7662 distances are derived.
Observations of Planetary-Nebula Spectra in the Near Ultraviolet
Authors: Kostjakova E. B.
Published: July 2016

Several dozen spectrograms of about 20 nebulae were obtained with the quartz spectrograph, placed at the Cassegrain focus of the 125-cm parabolic reflector of the Sternberg State Astronomical Institute Crimean Station. Nebulae with intense Balmer continuum were selected. Nearly half of them had not been studied before. Reductions were made for the nuclei spectra, for the differential atmospheric extinction and for the interstellar absorption. The A0 V stars were taken as absolute intensity standards. The work is not yet finished, but the results will be received in a short time.
Spectres de NGC 1976, IC 4997, NGC 6572 et IC 418 dans le Proche Infrarouge Photographique
Authors: Andrillat Yvette , Houziaux Léo
Published: July 2016

Une description qualitative des spectres d'une vingtaine de nébuleuses planétaires dans la région du proche infrarouge a été publiée en 1961 (Andrillat et Andrillat, 1961). Le spectrographe E' monté sur le télescope de 120 cm de l'Observatoire de Haute-Provence nous a permis d'entreprendre l'étude spectrophotométrique de quelquesunes de ces nébuleuses planétaires, ainsi que celle de la nébuleuse d'Orion. Ce spectrographe, pourvu d'un réseau par transmission de 300 traits au millimètre assure une dispersion pratiquement constante de 230 Å/mm dans le domaine de 5750 à 8000 Å. Les spectres obtenus sur plaques IN hypersensibilisées à l'ammoniaque, ont été calibrés photométriquement à l'aide d'un spectrographe à pénombre décrit par Barbier (1944).
Infrared Observations of the Planetary Nebula NGC 7027
Authors: Gillett F.C. , Low F.J. , Stein W.A.
Published: July 2016

An infrared spectrometer has been constructed with a resolution of Δλ/λ≈0·02 for observations in the wavelength range from 2·8 to 15 µ using a gallium-doped germanium bolometer (Low, 1961) as the radiation-sensitive element. Observations of the planetary nebula NGC 7027 were made with this instrument in May and June 1967 at the Catalina Observing Station of the University of Arizona. It was discovered that there was a measurable continuum flux from this object in the wavelength range from 7·5–14 µ that compared in value with the strength of stellar radiation from α Lyr (A0) at about λ = 9 µ. These observations are described in detail elsewhere (Gillett et al., 1967).
Radio Measurements of Planetary Nebulae
Authors: Thompson A. R.
Published: July 2016

Sixty-eight planetary nebulae have been investigated in a series of observations at 10-cm wavelength using the two 90-ft diameter antennas of the Owens Valley Radio Observatory. Of these, 52 were found to have flux densities greater than a minimum detectable level of approximately 10–27 Wm–2 Hz–1. To indicate cases of possible confusion in the radio observations, the measured radio position of each nebula was compared with an accurate optical position. For a number of the stronger nebulae angular widths in the East–West direction and flux densities at 21 cm were also measured. The results lead to the conclusion that the radio emission is thermal, and on this basis the expected flux densities in Hβ have been calculated. A comparison with optical data shows values of the Hβ extinction Δ log FHβ, ranging from zero to approximately 2·0 for NGC 6537 and NGC 6369.

A small number of nebulae show prominently the effects of self-absorption in their radio spectra. For two of these, IC 418 and NGC 6572, an attempt has been made to derive accurate optical depths and electron temperatures using models based on Balmer-line isophotes. The temperature values have large uncertainties, but appear to be less than the values derived from forbidden-line ratios by a factor of at least 1·5. A possible explanation of this difference in terms of temperature variations within the nebulae is discussed.

Preliminary results of observations to detect absorption features at the wavelength of the 21-cm hydrogen line are described for 6 nebulae with high radio-flux densities. Two nebulae, NGC 6369 and NGC 6857 show absorption which is probably attributable to hydrogen clouds within the galaxy. No definite evidence of absorption at frequencies near the radial velocities of the nebulae was found, and an upper limit on the mass of neutral hydrogen in two nebulae is briefly discussed.
On the Methods of Correction for the Interstellar Reddening of Planetary Nebulae
Authors: Arhipova V.P.
Published: July 2016

Knowledge of the interstellar extinction is of great importance for the study of the properties of planetary nebulae. An estimate of the interstellar reddening for an individual nebula may be obtained by means of three independent methods. In the first method the observed Balmer decrement is compared with the theoretical decrement (case B of Baker and Menzel). The second method consists of a comparison of the observed ratio of Balmer and Paschen intensities of lines, arising from a common upper level, with the theoretically predicted ratio. Finally, for thermal planetary nebulae with well-determined radio spectra, the optically thin part of their spectra can be used for a determination of interstellar reddening. Comparison of the radio flux from an optically thin nebula with the observed Hβ flux (in absolute units) allows us to evaluate the amount of extinction. Radio observations may thus give the interstellar extinction with high accuracy. It may especially be noted that the Balmer-decrement method, which is widely applied, gives satisfactory accuracy only if highly accurate H-line intensities are used. In all other cases it gives the most uncertain results, since its wavelength base-line is small. One must also take into account the fact that the Hα-line intensity is often not measured.
Dynamical Evolution of a Model Planetary Nebula
Authors: Mathews W. G.
Published: July 2016

The gas-dynamical equations for conservation of mass, momentum and energy, the ionization equation, and the equation of transfer for the ionizing radiation have been solved in a manner which approximates conditions in planetary nebulae. The ionized and neutral gas are assumed to heat and cool according to a linearized rate proportional to
On the Orientation of the Major Axes of Planetary Nebulae
Authors: Grinin V.P. , Zvereva A.M.
Published: July 2016

The orientation of the major axes of planetary nebulae was investigated and the results are given in Figure 1. The solid line gives the distribution of 132 planetary nebulae as a function of the angle Δϕ between the major axis of the nebula and the galactic equator. It can be seen that the distribution is not uniform, and is not symmetrical about Δϕ = 0. The dashed line gives the distribution of the same nebulae as a function of the angle between major axis of the nebula and the direction of the interstellar magnetic field, which is determined from the stellar polarization measurements of stars close to the individual nebulae. This distribution is less uniform than the first one but is symmetrical about Δϕ = 0. These results lead to the conclusion that the orientation of planetary nebulae is partly determined by the interstellar magnetic field.
Radial Velocity of the Central Star of NGC 1514
Authors: Mammano A. , Margoni R. , Perinotto M.
Published: July 2016

We would like to report on some spectroscopic observations made of the central star of the planetary nebula NGC 1514, which we think can support the binary hypothesis now advanced by Kohoutek.
Observational Aspects of the Evolution of Planetary Nebulae and their Central Stars
Authors: O'Dell C.R.
Published: July 2016

The greatest activity in the area of evolution of the central stars of the planetary nebulae has occurred in the last two decades, although there have been significant contributions by many workers of considerable insight ever since the early studies at the Lick Observatory demonstrated the physical nature of this class of nebula. We shall try to draw together here the many facets of the present picture of this rapidly developing and highly significant phase of stellar evolution. Unfortunately, the picture is not at all as complete as one would like, and there remain several points of scientific contention; however, we should like to present the results of several investigators. A certain amount of redundancy with previous papers given prior will be necessary, but we shall endeavor to treat these topics briefly and in the context of the evolution of the nebulae and their stars.
Production of Planetary Nebulae
Authors: Savedoff M.P. , Kutter G.S. , Van Horn H.M.
Published: July 2016

For various reasons, we have been studying evolution in the pre-white dwarf phase at Rochester. Our attention to the relevance of this work to planetary nebulae came as a result of calculations of the evolution of a one solar-mass iron star carried out at Rochester by S. Vila. Here the neutrino processes drive the peak luminosity to log L/L⊙=4·26, at an effective temperature log Teff=5·53. Although these models are brighter than 100 L⊙ for 500 000 years, they are brighter than 1000 L⊙ for 4000 years, and exceed 10000 L⊙ for 900 years. We are therefore near the luminosity of the planetary-nebula nuclei, but considerably hotter, for a period of the order of the planetary lifetimes. Except for the temperature discrepancy, these models are in rough agreement with the observationally determined evolutionary sequence found by O'Dell (1963) and by Harman and Seaton (1964) and Seaton (1966).
On the magnetic-field configuration in sunspots
Authors: Moe O. Kjeldseth
Published: July 2016

During 1963–67 observations of the magnetic fields in sunspots have been obtained at the Oslo Solar Observatory. For the largest spots the detailed distribution of the magnetic-field strength is found. Based on calculations of line profiles made by the author (Kjeldseth Moe, 1967) also the direction of the magnetic field is derived. Observations of the magnetic field of the same spot at several positions on the solar disk give further information regarding the magnetic-field configuration. Our results are in fair agreement with those of Bumba (1962).
The structure of the lower solar chromosphere in undisturbed and active regions
Authors: Dubov E.
Published: July 2016

As observational material in this work we used spectroheliograms taken with the Crimean solar tower telescope in K232 and Hα filtergrams taken with the chromospheric telescope in Simeis. The Hα birefringent filter was so adjusted, that by tuning the last polaroid we could take filtergrams in the centre of Hα or combined filtergrams in the two wings at Hα ± 0·5 Å. So the effect of Doppler shifts on image-brightness distribution was diminished. We compared the brightness distribution with that of spectroheliograms.
Cooperative study of solar active regions: Introductory Report
Authors: Michard R.
Published: July 2016

The ‘Cooperative Study of Solar Active Regions’ (or CSSAR) originated from a suggestion of E. R. Mustel at the IQSY General Assembly in Rome, 1963. Later on it was also endorsed by IAU Commission 10, and a special Working Group of this Commission, under chairmanship of the writer, had the duty to organize this project, an experiment in both solar physics and international cooperation.
Photographs of coronal streamers from a rocket on May 9, 1967
Authors: Tousey R. , Sandlin G. D. , Koomen M. J.
Published: July 2016

A photograph of the white-light corona from a rocket on May 9, 1967 showed many streamers, all straight and nearly radial, extending across the field of view, 3 to 9R⊙. At the North there were three spectacular streamers, making angles with the polar axis of 21° E, 20° W and 27° N. Projected inward, they were radial and passed through the probable positions of the principal plages on the back side.
Observations of energetic X-rays from quiescent solar active regions
Authors: Acton Loren W. , Fisher Philip C.
Published: July 2016

A measurement of the solar X-ray spectrum in the 1–30 KeV interval was made by rocket-borne instruments at 0015 UT on April 5, 1967. These measurements show that the solar X-ray spectrum, which falls off steeply with energy below 4 KeV, becomes less steep above this energy. These data are taken to indicate that energetic, non-thermal, electrons are present or continuously produced in quiescent solar active regions. No optical flare activity was reported for several hours around the time of these observations.
Radio emission of spotgroups
Authors: Kleczek J. , Olmr J. , Krüger A.
Published: July 2016

The slowly varying component (SVC) of solar radio emission and burst activity associated with different types of spotgroups from the past solar minimum have been investigated statistically.
The Measurement of Solar Magnetic Fields
Authors: Beckers Jacques M.
Published: July 2016

The different methods which have been used, or which may be used in the future, to measure solar magnetic fields are described and discussed. Roughly these can be divided into three groups (a) those which use the influence of the magnetic field on the electromagnetic radiation, (b) those which use the influence of the field on the structure of the solar atmosphere (MHD effects), and (c) those which use theoretical arguments. The former include the Zeeman effect, the Hanle effect, the gyro and synchrotron radiations and the Faraday rotation of radiowaves. The second includes the alignment of details at all levels of the solar atmosphere, and the calcium network, and the third makes use, for example, of the assumption of equipartition between magnetic and kinetic energy density.
A Complete Stokes Vector Polarimeter
Authors: Orrall Frank Q.
Published: July 2016

A scanning photoelectric polarimeter of 16 cm aperture that can measure all four Stokes parameters of the visible radiation of the Sun's disk, the Corona, Moon and planets, has been constructed at the Institute for Astronomy and is installed on Mt. Haleakala. It is a two (orthogonal) channel system and uses a rotating λ/4 plate modulator. Photon counting is done by a digital computer that also Fourier analyzes the modulated output of the photomultipliers, and, from the Fourier components, computes the Stokes parameters in real time.
Digital Videomagnetograms in Real Time
Authors: Janssens Thomas J. , Baker Neal K.
Published: July 2016

The Aerospace – NASA Videomagnetograph began operation one month ago, two years after components were ordered and construction began. The design grew out of a desire to obtain magnetic fields in real time using an optical filter. The aim was to study and analyze magnetic configurations and changes, quantitatively if possible, with high spatial and temporal resolution and as much sensitivity as possible. This instrument is restricted to the line-of-sight component of the magnetic field and is primarily intended for high resolution studies of selected regions of the sun. The rationale behind our approach is shown in the next section and the design details in the following.
The Interpretation of Magnetograph Results: The Formation of Absorption Lines in a Magnetic Field
Authors: Stenflo J. O.
Published: July 2016

The theory of line formation in a magnetic field is reviewed. It is shown how the formulations by Unno, Beckers, Stepanov and Rachkovsky are related to each other. The general treatment of true absorption, anomalous dispersion, radiative scattering and level-crossing interference is discussed. Special attention is paid to the inhomogeneous nature of the solar atmosphere. The properties of magnetic filaments are reviewed. It is shown how a filamentary structure will drastically influence the interpretation of magnetograph observations. The treatment of line formation in a turbulent magnetic field is also discussed.

The fine structure of the solar atmosphere will influence different types of magnetographs in entirely different ways. The relation between the observed magnetic field and the resolution of the instrument is discussed for a Babcock-type, Evans-type and a transversal magnetograph. Finally some suggestions for future work in this field are listed.
Coherence Properties of Polarized Radiation in Weak Magnetic Fields
Authors: House Lewis L.
Published: July 2016

The scattering of radiation in the presence of weak magnetic fields can give rise to coherence or interference phenomena that will profoundly affect the frequency, geometric, and polarization properties of the scattering event. In this paper we discuss and illustrate some of the features of the coherence phenomena associated with the scattering redistribution for the normal Zeeman triplet. The frequency dependent as well as the frequency independent scattering function is considered in a linear polarization basis. In addition we illustrate some properties of this redistribution function in the Stokes representation. Since the primary purpose of this paper is to demonstrate the nature of some of the properties of the coherence problems, that might be important in the interpretation of magnetic fields from polarization measurements of scattered radiation, it has been necessary in this initial work to neglect several features of the problem which are noted in the paper and are currently under investigation.
The Effect of Collisions on Spectral Line Formation in Solar Magnetic Regions
Authors: Lamb F. K.
Published: July 2016

The present paper describes the results of a preliminary investigation of the effects on the absorption, emission, and scattering of polarized light caused by collisions between the atoms of interest and surrounding perturbers under physical conditions typical of solar magnetic regions. The description of these effects in terms of atomic level polarization is reviewed and the processes which can lead to atomic level polarization in solar magnetic regions and those which tend to reduce it are summarized. The effects associated with collisional relaxation of atomic level polarization are discussed and a method for estimating relaxation rates is described. Estimates of collisional relaxation rates are used to calculate upper limits on the degree of polarization of the levels involved in the formation of five magnetically-sensitive FeI absorption lines. The implications of the results for the form of radiative transfer equations used to describe the formation of these lines are discussed.
On Magnetic Fields in Sunspots and Active Regions
Authors: Schröter E. H.
Published: July 2016

This review is restricted to a few topics of the extensive problem under discussion; it refers to the literature since 1967 only. The literature prior to 1967 is reviewed in Zwaan, 1968; Howard, 1967; Lüst, 1965; Kiepenheuer, 1968; Jäger, 1964; and Bray and Loughead, 1964.
Magnetographic and Spectrographic Observations of Weakly Active Regions
Authors: Durrant C. J.
Published: July 2016

The value of high resolution photo-electric observations of plage fields and their photospheric effects is demonstrated, with especial regard to obtaining an empirical model of a weakly active region.
Observations and Interpretation of Supergranule Velocity and Magnetic Fields
Authors: Musman Steven
Published: July 2016

I have studied the observed concentrations of vertical velocity and vertical magnetic field in the corners of the coarse network. Using a horizontal velocity inferred from the vertical velocity, I have computed the possible rate of concentration of the field. The rate turns out to be much higher than observed. I conclude that the observed motions in supergranules are not concentrating the observed field at the corners of the network. I have suggested four possible alternate situations consistent with the observations.
On Coronal Instability and Moving Radio Features Associated with a Flare Spray
Authors: Daigne G.
Published: July 2016

A solar radio outburst with its different parts well seen on metric wavelengths is described. A stable source shows successively two kinds of emission before the flash-phase of the event, and a moving type IV burst (V ≃ 1000 km/s), initiated 1/4 solar radius high, is directly associated with a spray-type prominence. Parameters of this radiating source are discussed.

A type II burst seen on lower frequencies with a spectrograph (V ≃ 3200 km/s) seems to start after the flash phase. Two possible cases are considered for the generation of the shock-wave responsible for type II burst.
Magnetic Fields Associated with Solar Flares
Authors: Mayfield Earle B.
Published: July 2016

An investigation of strong magnetic fields associated with flares was made with the 61 cm vacuum telescope and spectroheliograph at the San Fernando Observatory. Magnetograms of the longitudinal component of the field were made daily during the period of September 25–29, 1969. Observations were also made during this same period of the enhanced radio emission at 3.3 mm wavelength. On September 27 an importance class 3 or 4 flare occurred in the region studied. Total magnetic flux was determined for September 25, 26, 28 and 29 for the region which included the flare. In an area of about 190 arc s by 250 arc s the flux values for these dates were respectively 2.4, 2.5, 2.2 and 2.8 × 1022 Mx. Following the flare of September 27 the flux decreased significantly. Magnetic energy change in the region of the flare can be determined if an appropriate height is known. Following Howard and Severny (Astrophys. J. 137, 1242, 1963) a height of 109 cm was used. This yields a value of 5 × 1031 ergs for the decrease of magnetic energy in the longitudinal component of the field.
The Position Regularities of Flares Related to the Field Maximum in Sunspot Groups
Authors: Kasinsky V. V.
Published: July 2016

In this paper common regularities in flare positions have been studied in relation to spots as the extreme points of the magnetic field. The angular distribution diagrams of flares reveal that equatorial-western shifts of flares occurred during the I.G.Y. period (1957–58) in both hemispheres. This shift with some peculiarities is confirmed in the material of the 19th solar cycle, using the Solar Data bulletins, U.S.S.R., 1955–66. One result is that the western component of the shift does not change its sign and increases steadily during the cycle, while the equatorial component reverses sometimes and decreases steadily in amplitude to the end of the cycle.
Theories of Small-Scale Magnetic Fields
Authors: Sweet P. A.
Published: July 2016

This review is concerned with the origin of the fine structure of the fields and their relationship to the heating of the solar chromosphere and corona, the structure of prominences and the production of energetic particles in solar flares. The dynamics of sunspot formation, and the large-scale structure of individual sunspots have not been dealt with, although the evolution of AR fields has been considered insofar as it affects the flare problem.
Evolution of Turbulent Magnetic Fields – Approach to a Steady State
Authors: Nagarajan S.
Published: July 2016

The dynamical evolution of a weak, random, magnetic excitation in a turbulent electrically-conducting fluid is examined under varying kinematic conditions. It is found that the results of an earlier paper (Kraichnan and Nagarajan, 1967) can be reliably extended to a stage of evolution wherein the magnetic spectrum has reached local equipartition with the velocity. The transfer of the magnetic energy to smaller wavenumbers (larger scales) is considerable and significant. This result is highly pertinent to theturbulent dynamoquestion, which has been variously investigated recently. The relevance of the coupling of the rms magnetic field to the magnetic modes of all scales in deciding the efficiency of this transfer is discussed.
Experimental Study of the Orientation of Magnetic Fields in the Corona
Authors: Charvin P.
Published: July 2016

We present polarization measurements obtained in 1970 in the green coronal line with a new coronameter located at the Pic du Midi. The analysis of these data has been conducted with the theory given by the writer in 1964 and 1965. It appears that magnetic field orientations in the Corona can be deduced from the above measurements. First results showing large scale magnetic structures are presented.
Magnetic Fields in Polar Prominences
Authors: Smolkov G. Y.
Published: July 2016

The results of longitudinal magnetic field measurements in polar prominences (PP), obtained by Rust during 1964–1965 and by the author during 1966, 1969 and 1970, are considered. The magnetic field configuration in PP is similar to that of an arc. In opposite branches of such an arc the magnetic field has different polarities that do not coincide with the magnetic field polarity in current cycle BMR's. The magnetic field value increases as the angle between the line of sight and filament long axis grows. PP's reflect the behaviour of the border line between the magnetic fields of preceding and current cycles.
The Sun as a Magnetic Rotator
Authors: Tuominen Jaakko
Published: July 2016

Severny (1969) used a technique which enables the Sun to be observed like a magnetic star. Because of rotation, different sides of the Sun are visible at different times. A curve of variable magnetic field is obtained. During nearly three periods of rotation the Sun appears to be a quadrupole magnetic rotator. Generally, the integrated field of sunspots seems to be opposite to the field of the Sun as a whole. The curve seemed to remain similar throughout the year 1968.