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At least 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Recurrent active regions related to metric radio continuum emissions and the interplanetary magnetic sector structure

Active heliographic longitudes at the sun are investigated by using the observational data for long-lived metric continuum noise sources. It is shown that, for the period from 1963 to 1969, the number of such longitudes was four in general and these longitudes were very stable for this radio activity since 1963. A discussion is given on the relationship between those longitudes and the sector structure of the interplanetary magnetic field.

Sakurai, K.↗
NASA NTRS1971

Solution of the N-body problem with recurrent power series.

Adaptation of Steffensen's method of solution of both the restricted and general three-body problems in terms of power series in time to the solution of the equations of motion of N planets around the sun. The key feature of this adaptation lies in the introduction of N new variables and in the use of new relations which contain the time derivatives and can thus be treated as differential equations.

Broucke, R.↗
NASA NTRS1972

Twenty-seven-day recurrences in the solar-wind speed - Mariner 2.

Results of an autocorrelation analysis of the Mariner 2 data concerning solar-wind speed obtained in late 1962. A statistically significant correlation associated with the solar rotation has been found near a lag of 27 days; however, the amplitude of the correlation is only about 0.4, in essential agreement with measurements of Vela 2 and 3 during the period from July 1964 to July 1967. The relatively modest correlation is interpreted to mean that a number of speed structures observed by Mariner 2 did not endure for more than one solar rotation; those structures that did endure evolved significantly in shape, amplitude, and solar longitude from one solar rotation to the next. The analysis also shows that typical solar-wind structures occupied about 30 to 45 deg in solar longitude near 1 AU.

Gosling, J. T.↗
NASA NTRS1974

A recurrence matrix method for the analysis of longitudinal and torsional vibrations in non-uniform multibranch beams with variable boundary conditions

An approximate method for calculating the longitudinal and torsional natural frequencies and associated modal data of a beamlike, variable cross section multibranch structure is presented. The procedure described is the numerical integration of the first order differential equations that characterize the beam element in longitudinal motion and that satisfy the appropriate boundary conditions.

Davis, R. B.↗
NASA NTRS1976

Recurrent X-ray outbursts from Aquila X-1

Aquila X-1 observations by the All Sky Monitor on Ariel 5 are presented. Data is compared with that obtained by rocket survey, and by the Uhuru, OSO 7, and OAO 3 satellites. The variability of brightness is discussed as a connection between dwarf novae and long term transient X ray sources.

Kaluzienski, L. J.↗
NASA NTRS1977

Recurrent X-ray outbursts from Aquila X-1

Ariel V All-Sky Monitor observations of Aql X-1 are reported and compared with previous observations that indicate the existence of 'low' and 'high' intensity states. All the data considered are shown to be consistent with flaring episodes having a mean flare interval of 435 days with an rms scatter of about 10%. It is suggested that the observations are most easily interpreted in terms of an 'X-ray dwarf nova' binary of the type proposed for the transient X-ray source A0620-00. Constraints on more detailed features of the source model are discussed.

Kaluzienski, L. J.↗
NASA NTRS1980

Recurrent modulation of galactic cosmic rays and the anomalous helium

The observations of 27 day variations in the intensity of low energy cosmic ray protons (29-67 MeV) and anomalous helium (11-20 MeV/nucleon) are reported. These observations were made with instruments on IMP-8 in the earth orbit on Pioneer 11 at heliographic latitudes up to 16 deg and on Pioneer 10 at heliocentric distances of from 4 to 14 AU. 27 day variations are observed at all locations, most strongly in the anomalous helium, and reflect the very large scale structure of the interplanetary medium. Intensity minima are most often associated with high speed solar wind streams, but the physical mechanism producing the variations is not clear.

Bastian, T. S.↗
NASA NTRS1982

Recurrence of solar activity - Evidence for active longitudes

It is pointed out that the autocorrelation coefficients of the daily Wolf sunspot numbers over a period of 128 years reveal a number of interesting features of the variability of solar activity. Besides establishing periodicities for the solar rotation, solar activity cycle, and, perhaps, the 'Gleissberg Cycle', they suggest that active longitudes do exist, but with much greater strength and persistence in some solar cycles than in others. Evidence is adduced for a variation in the solar rotation period, as measured by sunspot number, of as much as two days between different solar cycles.

Bogart, R. S.↗