共查询到20条相似文献，搜索用时 78 毫秒
1.
Peter Rovithis 《Astrophysics and Space Science》1982,88(1):5-13
The sidereal daily rotation of the Sun, (), depends on the data used. From an appropriate selection of the data — sunspots with regular motion — it is found that ()=14.31–2.70 sin2 , where denotes the heliographic latitude. Moreover, it seems that there is a variation, of the order of 3%, with the solar activity. 相似文献
2.
We present a new method for measuring the solar magnetic meridional flow, and provide a comparison with other recent work. We have performed a least-squares fit to azimuthally averaged Mount Wilson Observatory synoptic data encompassing Carrington rotations 1722 to 1929 to produce an estimate of the solar meridional flow. A parametric fit to our results expresses the solar meridional flow as v() = 28.5 sin2.5 cos. 相似文献
3.
4.
Exponential and power law solutions for homogeneous cosmological modelshave been discussed in a generalized scalar-tensor theory where both thecosmological term and coupling parameter are taken tobe functions of the scalar field , along with the bulk viscousstress of the cosmic fluid. Assuming simple relationships of the scalarfield with the cosmological term and the coupling parameter, all thesolutions are studied in Dicke's revised units. By use of a conformaltransformation, the solutions are also expressed in atomic units. 相似文献
5.
A theory of gravitation with a flat background metric and a dynamical variable (variable gravitational constant) is investigated. It is shown that such bimetric scalar-tensor theory (BSTT) generalized GR as all the solutions of GR equations and(x) = constant satisfy BSTT equations, firstly, and BSTT equations contain non-Einstein solutions with the variable, secondly. Due to this fact, the problem on the agreement of BSTT with the observational data is reduced to the problem on the agreement of GR with the observational data and to the interpretation of the solutions with the variable. The latter may prove useful for the prediction of new effects. Examples of such effects are discussed. 相似文献
6.
The zonal structure of the distribution of filaments is considered. The mean latitudes of two filament bands are calculated in each solar hemisphere at the minima of the sunspot cycle in the period 1924–1986: middle latitude
2, m
and low latitude
1, m
. It is shown that the mean latitude of the filament band
2, m
at the minimum -m of the cycle correlates, with = 0.94, with the maximum - M sunspot area S(M) and maximum Wolf number W(M) in the succeeding solar cycle M. It is shown that the mean latitude of the low-latitude filament band
1, m
is linearly dependent on the mean latitude filament band
2, m + 1 at the succeeding minimum. We found a correlation of the latitude of the low-latitude filament band
1, m
with the maximum sunspot area in the M + 1 cycle. This enables us to predict the power of two succeeding 11-year solar cycles on the basis of the latitude of filament bands at the minimum of activity, 1985–1986: W(22) - 205 ± 10, W(23) - 210 ± 10. The importance of the relationships found for theory and applied aspects is emphasized. An attempt is made to interpret the relationships physically. 相似文献
7.
C.P. Singh 《Astrophysics and Space Science》2001,275(4):377-383
A spatially homogeneous and isotropic Robertson-Walker model withzero-curvature of the universe is studied within the frame-work of Lyra'smanifold. The gauge-function in Lyra's manifold is taken to betime-dependent. Exact solutions of Einstein equations are obtained for twodifferent early phases of the universe viz. Inflationary phase andradiation-dominated phase by using `gamma-law' equation of statep = ( - 1) . The -index, describing the material content,varies continuously with cosmic time so that in the course of itsevolution, the universe goes through a transition from an inflationaryphase to a radiation-dominated phase. The physical properties of themodels are also discussed. 相似文献
8.
In this paper we introduce a new parameter, the shear angle of vector magnetic fields, , to describe the non-potentiality of magnetic fields in active regions, which is defined as the angle between the observed vector magnetic field and its corresponding current-free field. In the case of highly inclined field configurations, this angle is approximately equal to the angular shear, , defined by Hagyardet al. (1984). The angular shear, , can be considered as the projection of the shear angle, , on the photosphere. For the active region studied, the shear angle, , seems to have a better and neater correspondence with flare activity than does . The shear angle, , gives a clearer explanation of the non-potentiality of magnetic fields. It is a better measure of the deviation of the observed magnetic field from a potential field, and is directly related to the magnetic free energy stored in non-potential fields. 相似文献
9.
A surprisingly good correlation has been found for SPA measured at VLF propagation () and 7 GHz solar microwave burst energies (E
). The data are correlated in the form = a log E
+ b and include all kind of solar events, irrespectively from type, complexity or duration. Soft X-ray peak fluxes (I
x) have a known similar correlation to SPA, and a functional relationship of the form 479-01 can be established. As one practical application, the energies from solar events can be reasonably well inferred from SPA data, which are quite reliable and easily obtainable. 相似文献
10.
R. K. Kochhar 《Astrophysics and Space Science》1978,55(2):395-400
In this paper we study the stability of an infinitely conducting, incompressible, inviscid infinite cylinder with non-parallel helical velocity and magnetic field. It is shown that the system is stable if the energy in the -component of the velocity field is larger than that in the -component of the magnetic field. 相似文献
11.
12.
The light curved in the CM field 总被引：1，自引：0，他引：1
In this paper we introduce the CM field in Sections 2 and 3 based on the paper by Wang and Peng (1985), and calculate the light curved in the CM field in Section 4. The result shows thatP makes CM larger than C at
, and smaller at
. Under a special circumstance which source, CM lens, and observer are in the same line, if we get |
0=0
,
and |
=/2
, we can determine theP(M) andQ(M) of the CM lens,M is the mass of the CM lens. 相似文献
13.
, , , , . , , . , , - - ( , ..). - . 相似文献
14.
The occurrence frequency distribution of sunspots in different magnetic flux values has been examined. The number of sunspots decreases as -1.9 for sunspots with magnetic flux greater than 3 × 1021 Maxwell, where is the said flux of a sunspot. 相似文献
15.
Spatially homogeneous and isotropic Robertson-Walker model of the universe is studied in Barber's second self-creation theory of gravitation in the presence of perfect fluid by using gamma-law equation of state p =(-1). The parameter gamma varies continuously with cosmological time. Exact solutions of the field equations are obtained for inflationary period and radiation-dominated era by using the power law relation Rn-3 = B. Some physical properties of the models are also discussed. 相似文献
16.
A.A. Ubachukwu 《Astrophysics and Space Science》1997,257(1):23-32
We examine a simple statistical consequence of relativistic beaming model using the core-to-lobe flux density ratio (R) and projected linear size (D) as orientation indicators. It is shown that the observed R-D intercept for the 3CRR source sample provides values of the bulk Lorentz factor () which are consistent with the beaming scenario. The result also shows that if the lobe-dominated quasars are to be unified with the core-dominated quasars, they should be oriented at a median angle, _med 40° with respect to the line of sight, but if with powerful radio galaxies, then _med 24°. Application of this result to the quasar-galaxy unification scheme using the observed angular size-redshift relation shows that the scheme is consistent with the observed data. 相似文献
17.
We present an attempt for an extension of the modified Boltzmann model, which was introduced by Callebautet al. (1982) as an improvement of the polytropic models, to the case of chemically-heterogeneous stars in equilibrium, containing H and He, by proposing a density profile of the formp=C
1
T
N
exp (–H
m(–*)/kT) +C
2
T
N
exp (–He
m(–*)/kT. Analytical properties are derived and numerical as well as analytical arguments are presented for the conclusion that this hypothesis for a density profile imposes an almost constant chemical profile to the model as a whole, thereby making it in this form unsuited for the study of heterogeneous stars. A comparison is made with the former Boltzmann model in the homogeneous limit. 相似文献
18.
, , , : - pll ( , ) N(E) =KE
–0, 0 1.5–2.5. , , =+- ); , :05 n 2.5, . , , 0 n = 2 + . , , - , . 相似文献
19.
Magnetogram data of 517 bipolar active regions are analyzed to study latitude, magnetic flux, polarity separation dependence of tilt angle of the active regions with well-defined bipolar magnetic configurations. The data were obtained at Huairou Solar Observing Station in Beijing during 1988 to October 2001. By statistical analysis, it is found: (1) The tilt angle () is a function of the latitude (). Our observed result, sin=0.5 sin, is in good agreement with that obtained by Wang and Sheeley (1991). (2) The tilt angle is a function of the magnetic flux. The tilt angle increases (decreases) with flux increasing when the flux is smaller (larger) than 5×1021 Mx. (3) The tilt angle is a function of the magnetic polarity separation. The tilt angle increases (decreases) with the separation increasing when the separation is smaller (larger) than 8×109 cm. (4) The magnetic flux ( in 1020 Mx) is correlated to the magnetic polarity separation (d in Mm), following 20d
1.15. The result is close to the observed result of Wang and Sheeley (1989), 20d
1.3. (5) The tilt fluctuations are independent of the latitude, but depend slightly on the separation, which is similar to the result obtained by Fisher, Fan, and Howard (1995). (6) The distribution function of the ratio of net magnetic flux to total magnetic flux is almost centered around zero net flux. The imbalance of magnetic flux is lower than 10% for 47% of our samples; 31% of active regions are in imbalance of the magnetic flux between 10% and 20%. 相似文献
20.
A. M. Finkelstein 《Celestial Mechanics and Dynamical Astronomy》1970,2(2):237-252
In the present paper the celestial mechanics consequences (light deflection, radar ranging of the planet, geodetic precession and secular effects in the orbital elements in the two-body problem) for the class of the theories based on the vacuum Jordan's Lagrangian has been considered. In these theories the gravitational constantG is proportional to –, being a scalar field and , some dimensionless parameter and the local law of conservation of the energy-momentum tensor holds. Of all these theories with different the most interesting one is that corresponding to =0. In the postnewtonian approximation this gravitational theory is completely equivalent to the general theory of relativity. 相似文献