On the detection of subphotospheric convective velocities and temperature fluctuations

A procedure is outlined for estimating the influence of large-scale convective eddies on the wave patterns of five-minute oscillations of high degree. The method is applied to adiabatic oscillations, with frequency ω and wave number k, of a plane-parallel polytropic layer upon which is imposed a low-amplitude convective flow. The distortion to the k - ω relation has two constituents: one depends on the horizontal component of the convective velocity and has a sign which depends on the sign of ω/k; the other depends on temperature fluctuations and is independent of the sign of ω/k. The magnitude of the distortion is just at the limit of present observational sensitivity. Thus there is reasonable hope that it will be possible to reveal some aspects of the large-scale flow in the solar convection zone.     

The GLE-associated flare of 21 August, 1979

We use a variety of ground-based and satellite measurements to identify the source of the ground level event (GLE) beginning near 06∶30 UT on 21 August, 1979 as the 2B flare with maximum at ～06∶15 UT in McMath region 16218. This flare differed from previous GLE-associated flares in that it lacked a prominent impulsive phase, having a peak ～9 GHz burst flux density of only 27 sfu and a ?20 keV peak hard X-ray flux of ?3 × 10^-6 ergs cm^-2s^-1. Also, McMath 16218 was magnetically less complex than the active regions in which previous cosmic-ray flares have occurred, containing essentially only a single sunspot with a rudimentary penumbra. The flare was associated with a high speed (?700 km s^-1) mass ejection observed by the NRL white light coronagraph aboard P78-1 and a shock accelerated (SA) event observed by the low frequency radio astronomy experiment on ISEE-3.     

Discovery of a flare star near Sirius

The discovery of a flare star (R.A. (1950)=6^h43^m6^s.07, Decl.(1950)=?16°45′24″) located about 6 arc min south of Sirius is reported. During photometric observations on the night of 13 January, 1982, using the 102 cm telescope at Kavalur, India, the star was seen to brighten by 2.55 mag. inV band over a duration of about 200 s. Observations on this object for a duration of about 10.5 hr spread over seven more nights indicate the star to be variable. The results of these observations are presented.     

Cosmic-ray antimatter: A primary origin hypothesis

We examine the possibility that the observed cosmic-ray protons are of primary extragalactic origin. The present \(\bar p\) data are consistent with a primary extragalactic component having \(\bar p\) /p?3.2±0.7 x 10^-4 independent of energy. Following the suggestion that most extragalactic cosmic rays are from active galaxies, we propose that most of the observed \(\bar p\) 's are alos from the same sites. This would imply the possibility of destroying the corresponding \(\bar \alpha \) 'sat the source, thus leading to a flux ratio \(\bar \alpha \) /α< \(\bar p\) /p. We further predict an estimate for \(\bar \alpha \) α～10^-5, within the range of future cosmic-ray detectors. the cosmological implications of this proposal are discussed.     

Hydrodynamical models of type II supernovae

A series of hydrodynamical models of type-II supernova outbursts (SNII) has been calculated. Approximate relations connecting the total outburst energy ε, the mass of envelope ejectedM, the presupernova radiusR, and the amount of ionizing quanta radiated by the supernovaeN _H with such values as the duration of the light curve plateau Δt, and absolute magnitude in the wavelength bandV and photospheric velocityU _PH observed near the middle of the plateau have been established. Advantage has been taken of the relations to obtain a preliminary evaluation for the characteristics of the average SN II: ε=7×10⁵⁰ erg,M=6M _⊙,R=500R _⊙,N _H=2×10⁵⁸. The SNIIs with plateau-like light curves seem to be accounted for by thermonuclear explosions of degenerate cores of red giant stars and result in a total disruption of the star without any stellar remnant. To the contrary, SNIIs with linear light curves have substantially different properties (in particular, they throw considerably less massive envelopes off). These SNII must signify the birth of collapsed objects—neutron stars (pulsars) or black holes.     

Cosmic ray composition estimation below the knee of the spectrum from the time structure of erenkov light in EAS

Monte Carlo simulations show that the pulse profile of erenkov photons measured near the core of an extensive air shower is sensitive to the secondary muon/electron ratio of the cascade. erenkov pulses can easily be measured with a single large area mirror viewed by a photomultiplier tube subtending a small field of view (1°). Even for such a simple experiment, exposed to EAS from a range of core locations and arrival directions, strong statistical differences are shown to exist between the pulse parameter distributions of primary protons and those of heavier primary particles. A range of primary energies can be investigated by varying the zenith angle of observations. In this paper, results from simulations of primaries in the energy range 20 TeV to 400 TeV are presented, although in principle the technique could be extended to include the knee of the spectrum. At the lower end of this energy range results can be compared to direct measurements of the composition, while measurements at the upper end can augment results from existing ground based experiments.     

The South African polymict eucrite Macibini

Abstract— The polymict eucrite Macibini is a fragmental breccia, predominantly composed of eucritic materials with minor proportions (maximum 2 vol%) of diogenitic material. Hence, it is intermediate between the Yamato‐74159‐type polymict eucrites, which contain negligible amounts of magnesian orthopyroxene, and the howardites. The present study provides mineralogical and bulk compositional data for the meteorite breccia and for six clasts. These clasts include both volcanic and igneous rocks and a variety of impact‐generated rocks. A broad range of degrees of postcrystallization metamorphism affected these materials before the final aggregation of the breccia. Clast A is a fragment of unequilibrated eucrite with subophitic texture. The edges of the zoned pyroxenes in this clast are composed of a host of Fe‐rich augite containing vermicules (blebs) and lamellae composed of a mixture of Fe‐rich olivine and silica. Similar features occur as fragments in lunar breccias and are attributed by some workers to the breakdown of pyroxferroite, an Fe‐rich pyroxenoid. However, textures and compositions of these augite‐olivine‐silica intergrowths in clast A suggest that, in this case, they are the result of decomposition in a series of steps of Fe‐rich subcalcic augite. Among the fragments of impact‐generated material in Macibini is clast 2, an earlier‐formed clastic breccia that was lithified before being broken apart and included in the meteorite breccia. Clast 3 is an impact‐melt breccia that is composed of rock and mineral fragments in a devitrified groundmass. Clast C is also an impact‐melt breccia that has a coarser‐grained, hornfelsic groundmass that resulted from extensive metamorphism after formation.     

The 12C/13C ratio in jupiter from the Voyager infrared investigation

The ¹²C/¹³C ratio in Jupiter has been derived from the analysis of the ν₄ band of CH₄ in the spectra recorded by the Voyager 1 IRIS experiment. It is found to be 160_?55⁺⁴⁰, i.e., 1.8_?0.6^+0.4 times the terrestrial value. Instrumental noise as well as systematic sources of error were taken into account for the estimate of the uncertainty. No plausible theory predicts such a difference between the values of the ¹²C/¹³C ratio in the inner solar system and in Jupiter. However, values of this ratio in the solar neighborhood 4.5 by ago inferred—through the use of models of chemical evolution of the Galaxy —from recent interstellar medium measurements are compatible with the present determination in Jupiter. The Jovian value, rather than the terrestrial one, could then be representative of the ratio in the primitive solar nebula.