Possibility of Excitation of Low-ℓ P-Modes by Energetic Solar Transients

We examine the temporal variation of power in low-ℓ modes using GONG data for the period of May 1995–October 2005 and compare this with disk-integrated flare and CME indices. A poor correlation between the running means of Flare Index and mode power is found. A similar result is found for CME Index also. Variations in the running mean mode power corresponding to ℓ = 0 modes with different radial orders are generally stochastic in nature. This behaviour is also reflected in the distribution of mode power.     

Average nocturnal and seasonal variations of sodium nightglow at 23°S, 46°W

The seasonal variation of the nocturnal average intensity, and the typical variation of the sodium airglow intensity during the night have been deduced, using a data set that has been accumulated over a period of 5 years. The maximum intensity, which occurs at the equinoxes, is about 2–3 times as large as the intensity during winter, when the intensity of the D₂ line is about 30 R. The nocturnal variation is symmetrical about midnight, where the intensity is some 30% less than just after (before) dusk (dawn) values.     

The Filament Disappearance of 7 May 1992 (the Ebi)

The 7 May 1992 filament disappearance in the low corona is analyzed. The cool and hot components of this event are studied, using H, soft X-ray and radio data. We first show the general effect of the disparition brusque (DB) on the life of the filament, which was a quiescent filament in the vicinity of an active region, and then give the history of the development of the 7 May event. The main stages of the event are: (i) the formation of hot arches spanning the cool filament; (ii) rise of the filament, with plasma ejection into the corona, in which we note some spreading of loops from the main body, with two distinct rising velocity phases of the H filament; (iii) formation of X-ray arches below the filament, the foot points of the arcades being two-ribbon H flare patches. The dynamics of H and X-rays features are given.     

The design of the Central-Axis Reflector (ZAS)

The Central-Axis Reflector, the design principle which is presented below is a segmented-mirror telescope. The inventions relate mainly to the optical system and to the tracking apparatus.A large number of small individual mirror bodies, ground off-axis (hexagonal/polygonal) produce one primary mirror with closed circular aperture when joined together.The overall design of the tracking apperatus results directly —and thus without unnecessary adornment — from the two planes of to aminimum but which are required for tracking of the telescope.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

MOUNTING PROBLEMS IN THE NAMING OF METEORITE DISCOVERIES

One of the most important steps in the recovery and study of meteorites is the concise naming of each fall so that confusion of one fall with another is avoided. The presently-used system of naming meteorite falls has been arrived at through an evolutionary process spurred on by necessity. The evolutionary history of the naming of meteorite falls is briefly sketched. Current naming practices are defined and the mounting problems of the present system are discussed. Measures for forestalling growing confusion in the naming of contiguous and overlapping falls, based upon a partial survey of curators of meteorite collections, are presented. A suggestion for the elimination of confusion in the dating of meteorite discoveries is included     

Some results of investigations of aurorae and night airglow during the I.G.Y. and I.G.C.

A general review is given of the results of the airglow and auroral investigations during I.G.Y and I.G.C. in the Institute for Atmospheric Physics of the Academy of Sciences of the U.S.S.R. A strong helium emission at 10830 Å has been discovered in sunlit aurorae and in the ordinary twilight airglow. It is now observed regularly. A detailed theory of this fluorescent emission has been developed. Extensive observations on the hydroxyl bands between 5000 and 12,000 Å have been carried out at a number of stations. Marked seasonal and geographical variations have been found in them. During intense aurorae the line-width of the 6300 Å emission from great altitudes increases. The effect has been studied using Fabry-Perot interferometers. Contributions have been made to knowledge on auroral morphology. The interpretation of some of the results which are described in the review are discussed.