Secular brightness increases of Titan,Uranus, and Neptune, 1972–1976     

G.W. Lockwood 《Icarus》1977,32(4):413-430

The brightnesses of Titan, Uranus, and Neptune in b (4718 ÅA) and y (5508 ÅA) have increased linearly since 1972 at rates ranging from 0.005 to 0.025 mag yr^?1. The observations were made differentially on a number of nights each season with respect to a network of comparison stars whose relative magnitudes were determined by independent measurements. Solar phase coefficients were derived for each object, and all observations have been normalized to zero solar phase angle and mean heliocentric distances. No explanation for the changes has been found, but a possible influence of solar activity upon planetary albedo is suggested by the fact that all of the objects observed have brightened during the declining half of the solar cycle.  相似文献   

Green's theorem and Green's functions for the steady-state cosmic-ray equation of transport     

G. M. Webb  L. J. Gleeson 《Astrophysics and Space Science》1977,50(1):205-223

Green's Theorem is developed for the spherically-symmetric steady-state cosmic-ray equation of transport in interplanetary space. By means of it the momentum distribution functionF _o(r,p), (r=heliocentric distance,p=momentum) can be determined in a regionr _arr_bwhen a source is specified throughout the region and the momentum spectrum is specified on the boundaries atr _a andr _b . Evaluation requires a knowledge of the Green's function which corresponds to the solution for monoenergetic particles released at heliocentric radiusr _o , Examples of Green's functions are given for the caser _a =0,r _b = and derived for the cases of finiter _a andr _b . The diffusion coefficient is assumed of the form = _o(p)r ^b . The treatment systematizes the development of all analytic solutions for steady-state solar and galactic cosmic-ray propagation and previous solutions form a subset of the present solutions.  相似文献   

Comparison between some Hα and X-ray flares     

R. Falciani  M. Giordano  M. Rigutti  G. Roberti 《Solar physics》1977,54(1):169-178

In the present paper, H-evolutive curves of chromospheric events are compared with flux evolutive curves of X-ray events observed at the same time in different spectral regions. A correspondence between the emissions E(I _H/I _chr)'s at higher and higher H-intensity levels, and the X-ray fluxes F()'s in harder and harder -ranges is shown. Further, the present observations seem to indicate the existence of a single triggering mechanism during the flash-phase of a flare. It is also shown that these results may be in agreement with Brown's model for chromospheric flares.  相似文献   

Energetic properties of interplanetary plasma at the earth's orbit following the August 4, 1972 flare     

C. D'uston  J. M. Bosqued  F. Cambou  V. V. Temny  G. N. Zastenker  O. L. Vaisberg  E. G. Eroshenko 《Solar physics》1977,51(1):217-229

Solar wind and interplanetary magnetic field data were obtained by the PROGNOZ 1 and PROGNOZ 2 satellites during the period following the August 4, 1972 (0621 UT) solar flare. A thermalized plasma was recorded one hour after the shock followed two hours later by the plasma piston with a bulk velocity higher than 1700 km s^-1. The comparison between the PROGNOZ and PIONEER 9 solar wind data shows an attenuation of the plasma properties with the deflection from the flare's meridian.  相似文献   

The polarization of the inner solar corona at the eclipse of 10 July 1972     

G. M. Nikolsky  A. A. Sazanov  A. K. Kishonkov 《Solar physics》1977,53(1):79-96

Photographs of the corona in the continuum spectrum (580–700 nm) have been obtained with a doublet camera (F=4m) through rotating sector polarizers with the vibrational directions oriented radially and tangentially to the solar limb. Isophotes of the total emission and its polarized component, as well as diagrams giving the degree of polarization for the (K+F)-corona and the electron corona proper (P _K), have been plotted up to the distance of 1R from the limb. In some inner regions the polarizationP _K exceeds the highest value possible for Thomson scattering under the given conditions. The reality of this anomally is dubious; systematic photometrical errors may account for it. Three-dimensional forms of 15 different coronal rays have been ascertained by comparing the course of polarization along the rays to the family of Baumach curves. The rays are found to deflect substantially from the radial directions out of the plane of the sky. Mean values of the coronal brightness and polarization versus the distance from the Sun have been determined. Contrary to well-known models (Van de Hulst) the mean polarization of the electron corona (P _K) decreases with distance after reaching the maximum (50%) at (1.4–1.6)R from the Sun's centre. This decrease can be explained by deflection of the streamers from radial directions.  相似文献   

The equations of motion of an artificial satellite in nonsingular variables     

G. E. O. Giacaglia 《Celestial Mechanics and Dynamical Astronomy》1977,15(2):191-215

The equations of motion of an artificial satellite are given in nonsingular variables. Any term in the geopotential is considered as well as luni-solar perturbations up to an arbitrary power ofr/r, r being the geocentric distance of the disturbing body. Resonances with tesseral harmonics and with the Moon or Sun are also considered. By neglecting the shadow effect, the disturbing function for solar radiation is also developed in nonsingular variables for the long periodic perturbations. Formulas are developed for implementation of the theory in actual computations.  相似文献   

A relation in families of periodic solutions     

M. Hénon 《Celestial Mechanics and Dynamical Astronomy》1977,15(1):99-105

We show the existence of a general relation between the parameters of periodic solutions in dynamical systems with ignorable coordinates. In particular, for time-independent systems with an axis of symmetry, the relation takes the form T/A=–/E, whereT is the period,A is the angular momentum, is the angle through which the system has rotated after one period, andE is the energy.  相似文献   

Magnetic properties of x-ray bright points     

L. Golub  A. S. Krieger  J. W. Harvey  G. S. Vaiana 《Solar physics》1977,53(1):111-121

Using high resolution KPNO magnetograms and sequences of simultaneous S-054 soft X-ray solar images we have compared the properties of X-ray bright points (XBP) and ephemeral active regions (ER). All XBP appear on the magnetograms as bipolar features, except for very newly emerged or old and decayed XBP. We find that the separation of the magnetic bipoles increases with the age of the XBP, with an average emergence growth rate of 2.2 ± 0.4 km s^–1. The total magnetic flux in a typical XBP living about 8 hr is found to be 2 x 10¹⁹ Mx. A proportionality is found between XBP lifetime and total magnetic flux, equivalent to 10²⁰ Mx per day of lifetime.Operated by the Association of Universities for Research in Astronomy, Inc. under contract with the National Science Foundation.  相似文献   

The north-south distribution of major solar flare events,sunspot magnetic classes and sunspot areas (1955–1974)     

Roy  J. -René 《Solar physics》1977,52(1):53-61

The north-south incidence has been studied of 31 white-light flares observed since 1859 and of 1669 events meeting the criteria for major flares of Dodson and Hedeman (1971) for the period 1955–1974. The asymmetry in favor of the northern hemisphere increases strikingly with the importance of the events. Similarly, magnetically complex sunspot groups (Mt. Wilson classes, and) display a more pronounced asymmetry in favor of the north than non-complex groups for 1962–1970. Contrary to the flare asymmetry, the spottedness asymmetry is independent of the size of sunspots.  相似文献   

The absorption of energetic electrons by argon gas     

J.L. Fox  A. Dalgarno  G.A. Victor 《Planetary and Space Science》1977,25(1):71-78

The processes by which energetic electrons lose energy in a weakly ionized gas of argon are analysed and calculations are carried out taking into account the discrete nature of the excitation processes. The excitation, ionization and heating efficiences are computed for energies up to 200 eV absorbed in a gas with fractional ionizations varying up to 10^?2.  相似文献