Recurrence formulae for the Hansen's developments.
Recurrence formulas for calculating Fourier expansions in elliptic motion in terms of eccentric and mean anomaly
Vinh, N. X.↗
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Recurrent nature of Lagrange multipliers for optimal low-thrust earth-Jupiter transfers.
Recurrent Lagrange multipliers for optimal low thrust earth-Jupiter transfers, using three dimensional solar system model
Fowler, W. T.↗
Further results on recurrent Lagrange multipliers for the low-thrust Earth-Jupiter transfer
Recurrent Lagrange multipliers coordinate transformation for optimal low thrust Earth- Jupiter trajectories
Fowler, W. T.↗
Recurrent solar cosmic ray events and solar M regions
Recurrent solar cosmic ray events and M region magnetic storms
Desai, U. D.↗
27-day recurrence and long term modulation of cosmic ray intensity.
Previous work by Balasubrahmanyan and Venkatesan (1970) on the general problem of the solar activity relationship with the 27-day recurrence and long term modulation of cosmic ray intensity, and Lockwood's (1971) comments thereon are discussed in the light of some further work. A possible explanation proposed for the absence of any time lag in both short and long term cosmic ray intensity changes views the long term variation as a result of a superposition of a number of short term decreases.
Balasubrahmanyan, V. K.↗
Solar coronal holes as sources of recurrent geomagnetic disturbances
Observations of the solar corona by Oso 7 have been used in a superposed epoch analysis to study the relationships between classes of coronal features and geomagnetic activity. Both bright coronal regions and regions of less than average brightness were investigated. It was found that for the period from January 1972 through January 1973, a significant enhancement in geomagnetic activity occurred 2-3 days after central meridian passage of large coronal holes that extended to within 5 deg of the solar subearth point when they were on the meridian. Large coronal holes appear to satisfy the requirements for 'M regions' which were hypothesized to be responsible for recurrent geomagnetic disturbances (Bartels, 1934). If solar wind high-speed streams originate preferentially in these regions, their velocity at the base of the corona will be substantially higher than that expected from an axisymmetric solar wind model.
Neupert, W. M.↗
On the efficient computation of recurrence relations
A new parallel algorithm for the solution of a general linear recurrence is described. Its relation to the work of Kogge and Stone is discussed.
Heller, D. E.↗
A0620-00 as a recurrent nova
Evidence for and against the star associated with A0620-00 being a nova is presented. The conclusion is that this star closely resembles other recurrent novae with the only unusual characteristic being the apparent high temperature at maximum brightness.
Liller, W.↗
Spectrophotometry of the unusual optical candidate for 3U 1728-24 (=GX 2+5 = GX 1+4) a recurrent nova?
The spectrum of the object suggested as a possible optical counterpart of GX 2+5, was studied, using the image tube scanner attached to the 3-m telescope of Lick Observatory. An improved X-ray error box obtained with Copernicus strongly supports this proposed identification. The candidate displays all the characteristics of the symbiotic stars and the related recurrent novae. The spectrum reveals the presence of an M star together with a blue component and a large number of emission lines displaying a wide range of ionization. There is evidence of variability of both the continuum and the line intensities. This object provides strong support for the often proposed association of some X-ray sources with nova-like systems.
Davidsen, A. F.↗
Recurrent brief X-ray bursts from the globular cluster NGC 6624
Observational data are presented on ten brief X-ray bursts, recurrent at nearly equal time intervals, recorded during a two-day observation of 3U 1820-30 in the globular cluster NGC 6624 with the wide-field modulation collimator detectors on the SAS-3 X-ray observatory. The occurrence times were fitted by least squares to a linear sequence with an rms deviation of 621 sec, corresponding to a phase jitter of 3.9%. The bursts were observed in two energy channels. For a sequence of five of the most clearly observed bursts, the 2-6 keV rate rose to its peak value in about 1 sec and then decayed to preburst level in about 10 sec. The 6-11 keV rate rose more slowly and decayed similarly. The smooth decay of their averaged light curve suggests the temporal evolution may have a geometrical origin, where Compton scattering in a surrounding cloud of hot plasma stretches the pulse out and causes a progressive hardening of the spectrum.
Clark, G. W.↗
Recurrence relations for computing with modified divided differences
Modified divided differences (MDD) provide a good way of representing a polynomial passing through points with unequally spaced abcissas. Recurrence relations for computing coefficients in either the monomial or Chebyshev basis from the MDD coefficients, and for computing the MDD coefficients for either the differentiated or the integrated polynomial are given. The latter operation is likely to be useful if MDD are used in a method for solving stiff differential equations.
Krogh, F.↗
Sources of magnetic fields in recurrent interplanetary streams
The sources of magnetic fields in recurrent streams were examined. Most fields and plasmas at 1 AU were related to coronal holes, and the magnetic field lines were open in those holes. Some of the magnetic fields and plasmas were related to open field line regions on the sun which were not associated with known coronal holes, indicating that open field lines are more basic than coronal holes as sources of the solar wind. Magnetic field intensities in five equatorial coronal holes ranged from 2G to 18G. Average measured photospheric magnetic fields along the footprints of the corresponding unipolar fields on circular equatorial arcs at 2.5 solar radii had a similar range and average, but in two cases the intensities were approximately three times higher than the projected intensities. The coronal footprints of the sector boundaries on the source surface at 2.5 solar radii, meandered between -45 deg and +45 deg latitude, and their inclination ranged from near zero to near ninety degrees.
Burlaga, L. F.↗
Coronal holes, solar wind streams, and recurrent geomagnetic disturbances - 1973-1976
Observations of coronal holes, solar-wind streams, and geomagnetic disturbances during 1973-1976 are compared in a 27-day pictorial format which shows their long-term evolution. The results leave little doubt that coronal holes are related to the high-speed streams and their associated recurrent geomagnetic disturbances. In particular, these observations strongly support the hypothesis that coronal holes are the solar origin of the high-speed streams observed in the solar wind near the ecliptic plane.
Sheeley, N. R., Jr.↗
Asymptotic behavior of vector recurrences with applications
An investigation is conducted of the behavior of a vector recurrence relation under very weak assumptions. The obtained results are used in an analysis of the iterations for nonlinear equations and a study concerning the composition of such iterations. The results can be employed in studies of one-point iterations involving the use of memory elements. Iterations for solving nonlinear equations on parallel computers can be investigated.
Feldstein, A.↗
The causes of recurrent geomagnetic storms
Interplanetary field and plasma data from earth-orbiting spacecraft during the period November 1973 to February 1974 were employed in analyzing the causes of recurrent geomagnetic activity. Two long sequences of geomagnetic activity and two corresponding corotating interplanetary streams figured in the data. The geomagnetic activity is discussed in terms of the electric field produced by the ordered mesoscale pattern of the stream itself, and by random smaller-scale fluctuations in the southward component of the interplanetary magnetic field.
Burlaga, L. F.↗
Sources of magnetic fields in recurrent interplanetary streams
The paper examines sources of magnetic fields in recurrent streams observed by the Imp 8 and Heos spacecraft at 1 AU and by Mariner 10 en route to Mercury between October 31, 1973 and February 9, 1974, during Carrington rotations 1607-1610. Although most fields and plasmas at 1 AU were related to coronal holes and the magnetic field lines were open in those holes, some of the magnetic fields and plasmas at 1 AU were related to open field line regions on the sun which were not associated with known coronal holes, indicating that open field lines may be more basic than coronal holes as sources of the solar wind. Magnetic field intensities in five equatorial coronal holes, certain photospheric magnetic fields, and the coronal footprints of the sector boundaries on the source surface are characterized.
Burlaga, L. F.↗
The radial diffusion coefficient of 1.3 - 2.3 MeV protons in recurrent proton streams
The paper presents anisotropy measurements of 1.3-2.3 MeV protons in the interplanetary space during recurrent events for which the radial intensity variation is measured within the radial range from about 0.3 to about 4 AU for the period from June, 1973 through April, 1976. The simultaneous measurements of the diffusive anisotropy and the radial gradient are used to make a direct estimate of the interplanetary radial diffusion coefficient, which is independent of any particular solution of the propagation equation. IMP 7 and 8 is required to be sunward of the earth and hence outside of the magnetosphere; if both spacecraft are sunward, measurements from the one farthest from the magnetosphere are used. The resulting values for the radial diffusivity coefficient near 1 AU lie in the range (3 to 9) x 10 to the 20th sq cm/sec, corresponding to scattering mean free paths between 0.03 and 0.1 AU with a mean of 0.06 AU.
Mewaldt, R. A.↗
Location of the recurrent /LMC/ X-ray transient A0538-66 with the HEAO 1 scanning modulation collimator
Two brief (about 12 hr) X-ray flares from the direction of the Large Magellanic Cloud have been observed with the HEAO 1 scanning modulation collimator. It is argued that both originated from the recurrent fast transient A0538-66, first observed with the Ariel 5 satellite. A precise position for the source is obtained, and a B2 Iab star in the Large Magellanic Cloud is suggested as the optical counterpart. Evidence for a 16.66-day periodicity in the outburst times is presented and discussed.
Johnston, M. D.↗