These changes, as well as many advances in science and technology, are forcing us to reassess the basic science policies and goals of the Astrophysical Observatory. Its purpose is to "increase and spread knowledge" in the field of astrophysics, with special emphasis on the problems of the sun, earth, and solar system.
S. Bowen l
The characteristics of this receiver play a very large role in the correct design of the telescope. These variations are due to spectroscopic differences in the small regions imaged on the spectrograph's slit.
By Geoffrey Keller
A fairly complete theory of the relationship between the atmospheric irregularities and the pattern of light and dark in the shadow pattern has been developed by van Isacker (1953). With a reliable means of studying the structure of the shadow pattern, much can be said about the pattern of density variations in the air itself.
By Charlotte E. Moore
We need a more accurate knowledge of Oort's constant A near the Sun. A proposed alternative scheme involves storing the released charge on a mosaic, as in the image orthicon.
IRECEIVERI CABLE ANTENNA B
DIRECTIONAL RESPONSE WITH EQUAL CABLE
LENGTHS; SIGNALS FROM OVERHEAD SOURCE ADD
I RECEIVER! -g- X
HALF WAVE DIFFERENCE IN CABLE LENGTHS
SIGNALS FROM OVERHEAD SOURCE CANCEL
MAIN LOBE OF X ^
PRINCIPAL LOBE WHEN
PATTERNS ARE MULTIPLIED
MAIN LOBE OF "B"
OUTPUTS TO RECEIVER
PATH OF STAR
One interesting problem was the calculation of the history of a globular swarm (in two dimensions). The structure of the Earth's upper atmosphere can be studied extensively and accurately by various techniques. The non-linearity of the equations is again a source of complications in the kinetic theory of plasmas.
The development of the subject has barely begun and the field is wide open.
By Eugene N. Parker
This loosening process forms one of the basic steps in the regenerative hydromagnetic alternator discussed below. The tension in the lines of force and the mass of the fluid clinging to them indicate that the. However, it is interesting to note that the presence of the magnetic field can promote the generation of acoustic waves (Kulsrud, 1955).
The radio emission is thought to arise from the collisions of the interstellar gas clouds that occur in the interpenetrating galaxies (Greenstein and Minkowski, 1954).
Jiartti s Magnetism
The secular variation (which is essentially the time derivative of the non-dipole component of the geomagnetic field) originates from a relatively thin layer at the top of the core. Some of the magnetic field generated in the core by penetrating the mantle creates a mechanical force there. In the Earth's core and even more so in the star, Rm is usually quite large numerically.
A connection between rotation and dynamo operation is clearly indicated by the behavior of the Earth's magnetic field and is confirmed.
By William Markowitz 1
The probable error in the differences between atomic and astronomical times will be almost entirely due to uncertainties in the latter. Therefore, research in both areas should be encouraged so that results can be obtained with the highest possible accuracy. Observing techniques have improved over the years, and other astronomers in the United States have been freed from the need to do similar work.
The end result is that, because of the general shortage of scientists and astronomers as a whole, there is a particularly acute shortage of astronomers entering these fields.
By John A. O'Keefe *
The disadvantage of this method is that the photometric observations are disturbed by the scintillations of the beads. A very similar technique begins by observing the occultation of the stars by the moon. The most important change in geodesy of the future may come with the use of satellite.
The satellite can be used as Hiran's aircraft and flare observations.
By John S. Rinehart 1
The apparent age of the stone phase of meteorites determined by each method is in close agreement, about 4X109 years. Physical metallurgy has contributed significantly, though not largely, to our knowledge of the origin and age of meteorites. Of particular importance are the Widmanstatten numbers, the local concentration of nickel in the elements of the figures, and the phase transitions that indicate pressure changes.
Studying craters gives us great insight into the cosmological role of such physical encounters.
By Fred L. Whipple *
In the near future, such information must be collected, summarized and interpreted with a view to increasing our understanding of it. A corresponding quantity is the ionization efficiency, measuring the number of electrons released in the meteoric process by each atom of the meteorite. The physics of the meteoric process involves the integration of physical data, physical phenomena, and meteoric phenomena into a coherent whole.
Here we require a more comprehensive theory of the perturbing effects of a minor planet on microparticles in the solar system.
By PaulHerget 1
Recent work at the Naval Observatory and by Kuiper has revealed new problems related to the physical constitution and history of the minor planets. There is already some evidence that two classes of smaller planets can be recognized from polarization observations. Another program, already well underway, will use the first four minor planets to determine the position of the equinox instead of observations of the Sun and the major planets.
More penetrating research can now be done on the families of minor planets originally recognized by Hirayama.
By Gerard P. Kuiper *
Nor do we know the orbits of the planets with an accuracy very different from that of the Earth's orbit. The atmospheric component of the night sky's light arises from: (a) scattering of starlight and extraterrestrial radiation in our atmosphere, (b) atomic emissions in the form of monochromatic emission lines, (c) molecular emissions in the atmosphere. shape of emission bands and possibly continua, and (d) Cerenkov radiation and N2+ emission from cosmic rays. The relative intensities generally appear abnormal, especially for neon in red due to the.
In the case of altitudes, very clever instruments have been devised to measure the speckle and speckle movements of the aerial illumination.
By Walter Orr Roberts*
At the moment of the explosion, there was a fluctuation in the strength of the earth's magnetic field. Although our understanding of the solar physics of the situation is very imperfect, we infer that the observed large changes in coronal emission probably imply large changes in the Sun's total ultraviolet or X-ray emission. However, the total energy changes of the sun's emission must be very small, perhaps measured in thousandths or millionths of the solar constant.
Better will come from such a unified view of solar activity, as well as the quiet sun.
By Leo Goldberg 1 and Donald H. Menzel 3
Additional problems of an even more basic nature stand in the way of a definitive model of the photosphere. Arguably, solving the problem of telescopic viewing is now the most important instrumental challenge in solar physics. These remarkable photographs record the rapid changes that occur in the irregular structure of the outer chromosphere.
A more important development has been in the field of classification of the faint inhabitants of dust clouds - T Tauri stars - by Joy (Mount Wilson), Herbig (Lick) and Haro (Tonantzintla).
By Marshal H. Wrubel'
It is hoped that Schwarzschild's unorthodox plan to "see" the sun from above will be successfully implemented in the near future. Brand new theoretical techniques will need to be combined with laboratory data on molecular absorption before we have as detailed an explanation of the atmospheres of late-spectral-type stars as we have of the Sun. Observations point to a "web of prominences" far more extensive than the Sun's; and if understanding the dynamic atmosphere is important on the Sun, it is crucial here.
Thus, our current understanding of the atmosphere of pulsating variables, magnetic stars, Wolf-Rayet stars, etc. is rudimentary at best.
By Richard N. Thomas*
The surface brightness and isophotic contours can be measured for each of the stronger monochromatic emissions. Densities and temperatures of the radiating gases can be determined from the brightness of the surface and from spectroscopic data. Often, however, the [N II] and [O III] lines are predominantly produced in different regions of the nebula.
The origin of the magnetic fields and the source of the particles' energy are not explained.
By Otto Struve x
We need periodic determinations of the velocity curves of all the brightest spectroscopic binaries. WX Cephei (J. Sahade and C. U. Cesco) shows striking changes in the intensity of the two components of the Ca II absorption. It is one of the most peculiar binaries in this respect, resembling XZ Sagittarii (J. Sahade).
It is important to know if the depth of the eclipse (totality ended in early December 330 days later) is really the same in all wavelengths.
ByU. Van Wijk 1
Periodic variables.—Classical Cepheids and parallel sequence of population I I variables are rich in possibilities. Explosive variables. — The most difficult problem, which can only be tackled with the largest telescopes, is the physical processes of supernovae, and above all the unsolved problem of their spectroscopic changes. The study of the new ones themselves has always been hindered by the unexpectedness of the eruptions.
Irregular Variables.—The faint irregular variable stars in the nebula are destined to play an important part in ideas of the origin and development of stars.
By Lyman Spitzer, Jr. 1
For example, data is gradually accumulating on what can be called interstellar meteorology - the great problem of movements and transformations of the interstellar clouds. The comprehensive analysis of the many simultaneous processes will obviously be a big and challenging adventure. In particular, the detailed structure of the grains, the forces that hold them together, and indeed all but the grossest properties of these tiny solid particles are completely uncertain.
However, given the enormous interest in this particular problem, it seems certain that much new work will be done in the coming decades.
By Bart J. Bok '
The study of the spiral structure in the part of our galaxy inside our sun presents a variety of complex problems. The third group of problems that appear amenable to study with 21 cm techniques concerns the fine structure of the interstellar hydrogen medium. Through the 21 cm study we learn a lot about the dynamics of the two Clouds.
The importance of 21-cm surveys for individual galaxies in the Local Group can hardly be overstated.
By Harold Weaver 1
The distances of the hydrogen condensations are only correct to the extent that (1) an accurate differential rotation function Aw(R) is available, and (2) the interstellar gas is free of large-scale peculiar motions. Space variations of the extinction law complicate photometric distance calculations and pose difficult problems for the theorist trying to explain the particle size distribution in the interstellar material. If derived from stars, Aco(i?) depends on the precision of the stellar distance scale.
Baade's estimate could be significantly changed by a small revision of the applied interstellar extinction correction.
GALACTIC CENTER
The u(R) curve derived by Kwee, Muller and Westerhout (1954) from 21-cm observations shows waves which, according to them, represent deviations from circular motion correlated with position with respect to spiral structure.
CENTER /
Essentially, the integrated quantities represent certain average properties of the stellar population in the defined volume element. We must also consider the double or multiplicity of stars and their movements in the group. At the focus of a large telescope, a globular cluster is one of the most magnificent sights in the sky.
Except in the immediate vicinity of the galactic nucleus, the number of globular clusters per unit.
At the bottom of each diagram, from M , ~ + 4 down, is a segment of the main sequence. Among the various branches of cluster diagrams, the main sequence is observationally the most difficult. We have already mentioned the number of variables as an index in the form of the color size diagram according to the A series.
As already noted, the globular clusters probably do not share much of the overall rotation of the galaxy.
By John D. Kraus *
