Modelling solar irradiance variations with an area dependent photometric sunspot index

The He 1083 nm line equivalent width and the 10.7 cm radio flux are employed to model the total solar irradiance corrected for sunspot deficit. A new area dependent photometric sunspot index (APSI) based on sunspot photometry by Steinegger et al. (1990) is used to correct the irradiance data for sunspot deficits. Two periods of time are investigated: firstly, the 1980–1989 period between the maxima of solar cycles 21 and 22; this period is covered by ACRIM I irradiance data. Secondly, the 1978–92 period which includes both maxima; here, the revised Nimbus-7 ERB data are used.For both He 1083 nm and 10.7 cm radio flux irradiance models as well as ACRIM I and ERB irradiance data, the APSI yields an improved fit compared to the one obtained with the standard Photometric Sunspot Index (PSI) which uses a constant bolometric spot contrast. With APSI, the standard deviation calculated from daily values is 0.461 Wm^–2 for the period 1980–89 modelling ACRIM I vs. He 1083 nm, as compared to 0.478 when PSI is used, and to 0.531 for the uncorrected ACRIM series. A similar improvement is obtained for the same period modelling ERB vs. He 1083 nm, while there is almost no improvement for the long period.As a general result the models provide a good fit with the spot-deficit.-corrected irradiance only during the period between the maxima. If both maxima are included (period 1978–92) the He 1083 nm and 10.7 cm radio flux models show appreciably larger discrepancies to the irradiances corrected for PSI or APSI.     

Hollow beam distribution of energetic electrons and higher harmonics of electron cyclotron maser

The variations of the growth rates of ECM at first four harmonics in X-, Z-, and O-modes excited by a hollow beam distribution of weakly relativistic electrons with a parameter _p / _e are presented in this paper. The results show that the second harmonic of ECM in X-mode dominates the instability if < 1, and if 1.2 , 2 or 2.2 3 the third or fourth harmonic will dominate. The second and third harmonics of Z-mode waves grow faster only if 2 2.2 and 3 3.2, respectively, so it would not be a competition in most cases. It is suggested that the ECM emission at these harmonics in X-mode is a possible mechanism to produce solar spike emissions with high brightness temperature at shorter and longer decimetric wavelengths.Proceedings of the Workshop on Radio Continua during Solar Flares, held at Duino (Trieste), Italy, 27–31 May, 1985.On leave from the Department of Astronomy, Nanjing University, Nanjing, The People's Republic of China.     

Multiperiodic irradiance changes caused by r-modes and g-modes

More than 20 real periodicities ranging from 20 days to 2 years modulate the solar irradiance data accumulated since November 1978 by Nimbus 7. Many are quite strong during the first three years (solar maximum) and weak after that. There is a high correspondence between periods in irradiance and 28 periods predicted from the rotation and beating of global solar oscillations (r-modes and g-modes). Angular states = 1, 2, and 3 are detected as well as some unresolved r-mode power at higher . The prominence of beat periods implies a nonlinear system whose effective nonlinear power was measured to be about 2. This analysis constitutes a detection of r-modes in the Sun and determines from them a mean sidereal rotation rate for the convective envelope of 459 ± 4 nHz which converts to a period of 25.2 days (27.l^d, synodic).     

The limits of possible values of inclination of Mercury's equator

The method of estimation of the limits, containing the equator inclination of a celestial body, had been developed. In this method it is necessary to know the orbital elements and the mass of a celestial body. Another condition is that the axial rotation of a body should be in the resonance with its orbital motion. It has been found that the equator inclinations should have the values between 1 .7 and 2 .6 for Mercury and between 1 .0 and 1 .8 for the Moon. It also has been found that largest harmonics in Mercury's physical libration are the harmonics sin( – 3g), cos( – 3g), sin g and sin 2.     

Earth Tides and Lense–Thirring Effect

The general relativistic Lense—Thirring effect can be measured by inspecting a suitable combination of the orbital residuals of the nodes of LAGEOS and LAGEOS II and the perigee of LAGEOS II. The solid and ocean Earth tides affect the recovery of the parameter by means of which the gravitomagnetic signal is accounted for in the combined residuals. Thus an extensive analysis of the perturbations induced on these orbital elements by the solid and ocean Earth tides is carried out. It involves the l=2 terms for the solid tides and the l=2,3,4 terms for the ocean tides. The perigee of LAGEOS II turns out to be very sensitive to the l=3 part of the ocean tidal spectrum, contrary to the nodes of LAGEOS and LAGEOS II. The uncertainty in the solid tidal perturbations, mainly due to the Love number k ₂, ranges from 0.4% to 1.5%, while the ocean tides are uncertain at 5–15% level. The obtained results are used in order to check in a preliminary way which tidal constituents the Lense-Thirring shift is sensitive to. In particular it is tested if the semisecular 18.6-year zonal tide really does not affect the combined residuals. It turns out that, if modeled at the level of accuracy worked out in the paper, the l=2,4 m=0 and also, to a lesser extent, the l=3, m=0 tidal perturbations cancel out.This revised version was published online in October 2005 with corrections to the Cover Date.     

STATISTICAL PROPERTIES OF THE PULSES IN THE SOLAR p-MODE POWER

We have revealed the periods of good visibility for each individual mode of low spherical degree using irradiance data from the IPHIR experiment. Their statistical properties and the influence on the resulting line shapes are discussed. The analysis of the temporal change of each mode power by Fourier transform with a running temporal window was performed. The running mean power of p-modes (=0, n=17–24 and =1, n=16–23) apparently changes with the rotation of the Sun. There is well visible an anticorrelation of the p-mode power with the mean solar magnetic field and less significant correlation with daily sunspot number.     

Взаимооействие Излучения Рентгеновскооо Истооника с АтмосФерой Нормальной Звезды в Тесных Двойных Системах

, . : , . , . . ( ) . . . HZ Her=Her X1, . . , . , ., hv 15–30 . , . Sco X1 .     

Some fundamental elements of universe mechanics

An essential part in the mechanics under study is taking into consideration the effect of motions of the Universe objects upon that of an individual one surrounded by them including those infinitely far from it. Only macro-objects of the Universe are meant here.

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Zusammenfassung Ein wesentlicher Bestandteil der Mechanik unter unserer Betrachtung ist die Berechnung des Einflusses auf die Bewegung eines individuellen Objektes von Bewegungen der Universum Objekte die es umringen einschließlich jene Objekte, die unendlich entfernt sind. Nur Makroobjekte des Weltalles sind in der Absicht dabei.

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, . .

     

Метагалактические протоны сверхвысоких энергий

, . 2.7°- . . . E3×10¹⁹ (1.6) .     

Einstein-like field equations with conserved source and decreasing ∧ term; Their cosmological consequences

The consequences of a cosmological term varying asS ^–2 in a spatially isotropic universe with scale factorS and conserved matter tensor are investigated. One finds a perpetually expanding universe with positive and gravitational constantG that increases with time. The hard equation of state 3P>U (U mass-energy density,P scalar pressure) applied to the early universe leads to the expansion lawSt (t cosmic time) which solves the horizon problem with no need of inflation. Also the flatness problem is resolved without inflation. The model does not affect the well known predictions on the cosmic light elements abundance which come from standard big bang cosmology.In the present, matter dominated universe one findsdG/dt=2H/U (H is the Hubble parameter) which is consistent with observations provided <10^–57 cm^–2. Asymptotically (S) the term equalsGU/2, in agreement with other studies.     

Космическое черенковское излучение

, . N/E, E _r, (E _r)=1. , (, ) . .     

Результаты и проблемы исследования синхротронной неустойчивости

, . , . . , (, ). , ( , ).     

Quantum effects in cyclotron plasma absorption

It is shown that X-ray radiation of neutron stars with magnetic fieldsB=10¹¹–10¹³ G near cyclotron resonances=s _B (s=1,2,...) is deeply affected by such quantum effects as electron-positron vacuum polarization (significant at V=3×10²⁸ n _e ^–1 (B/B _C ⁴)1, whereB _C =4.4×10¹³G), the quantizing character of the magnetic field (significant atV=3 x 10²⁸ n _e ^–1 (B/B _c)⁴1 whereB _c =4.4 x 10¹³G), the non-harmonic character of the Landau levels, and the quantum recoil of electrons. The latter two factors shift the resonances by the frequency –s ² _B (B/2B _c )sin², being the angle between the direction of radiation propagation and the magnetic field. IfVV ₀ (for 1,V ₀^–1=(mc ²/2T)^1/2), the normal mode (NM) polarizations, as well as the absorption coefficientk ₁ of the extraordinary NM in the Doppler core of the first resonance (|–| _B cos ), is only slightly affected by varyingb and/orV, whereas for the ordinary NM (at 1)k ₂k ₁ ²[b + (3 + tan²–2V)²]k ₁. For sufficiently largeb and/orV the quantum effects amplify resonant absorption of the ordinary NM at _B , with spin-flip transitions playing a major role atb1+V ². IfVV ₀, the coefficientsk ₁ andk ₂ in the Doppler core of the resonance are of the same order and acquire some peculiar features (shifts, intersections, etc.), with the NM polarizations depending sharply on and being strongly non-orthogonal. AtVV ₀,k ₂=k ₁(cos² +B/2B _C ) and the polarizations are almost linear. Near high resonances (s2), as a rule,k _1,2(1 + b) ^{s–1 2s–3} i.e., absorption increases withb due to replacement of the thermal energy of the transverse motion of electron,T, by the magnetic energy _B . The above effects should be taken into account for an interpretation of observational data on X-ray pulsars (e.g., Her X-1) and other X-ray sources associated with neutron stars.     

Statistical survey of planetary nebulae: Distances,masses, and distribution in the galaxy

On the basis of empirical (D)-dependency at the frequency of 5 GHz constructed using 15 planetary nebulae with the independently measured distances (10^–171×10^–20 W m^–2 Hz^–1 ster^–1), we evaluated distances of 335 objects. Independent evidence of the correctness of the accepted scale are given. Then(D)-dependency is constructed and it is shown that atD<0.08 pc the mean electron density is higher than the one determined by the Seaton method. We showed that the filling factor diminishes with the increase of the PN diameter (1 atD0.08 pc and 0.2 atD0.4 pc). the ionized mass of 33 PNs is determined. With the diameter increase the ionized mass grows and atD0.4 pc reaches the valueM0.07M . We used the new distance scale when investigating the space distribution of PNs. The mean scale height =130±15 pc and the mean gradient of the change of surface densitym=0.37, which allowed us to estimate the total number of nebulae in the GalaxyN4×10⁴. We divided the PNs according to their velocities (withV _LSR>35 km s^–1 andV _LSR<35 km s^–1) and permitted us to confirm that the PN belong to different sub-systems of the Galaxy. The estimated local formation rate of PNs [=(4.6±2.2)×10^–12 pc^–3 yr^–1] is a little higher than the one of the white dwarfs. That can be explained by a large number of PNs having binary cores, which used in our sample. The statistical estimation of PN expansion velocity showed thatV _ex increases from 5–7 km s^–1 (atD0.03 pc) to 40–50 km s^–1 (atD0.8 pc).     

Динамические равновесные плазменные конфигуации и физика магнитосферы

, 1-, 2- 3- . , .     

Mgix emission lines in an active region spectrum obtained with the Solar EUV Rocket Telescope and Spectrograph (SERTS)

Theoretical electron-temperature-sensitive Mgix emission line ratios are presented forR _I =I(443.96 )/I(368.06 ),R ₂ =I(439.17 )/I(368.06 ),R ₃ =I(443.37 )/I(368.06 ),R ₄ =I(441.22 )/I(368.06 ), andR ₅ =I(448.28 )/I(368.06 ). A comparison of these with observational data for a solar active region, obtained during a rocket flight by the Solar EUV Rocket Telescope and Spectrograph (SERTS), reveals excellent agreement between theory and observation forR ₁ throughR ₄, with discrepancies that average only 9%. This provides experimental support for the accuracy of the atomic data adopted in the line ratio calculations, and also resolves discrepancies found previously when the theoretical results were compared with solar data from the S082A instrument on boardSkylab. However in the case ofR ₅, the theoretical and observed ratios differ by almost a factor of 2. This may be due to the measured intensity of the 448.28 line being seriously affected by instrumental effects, as it lies very close to the long wavelength edge of the SERTS spectral coverage (235.46–448.76 ).     

Electron-cyclotron maser emission from the sun and stars: Variations with plasma temperature and density

Very bright and highly circularly polarized radio bursts from the Sun, the planets, flare stars, and close binary stars are attributed to the electron-cyclotron maser instability. The mode and frequency of the dominant radiation from the maser instability is shown to be dependent on the plasma temperature and the ratio _p / _e of the plasma frequency to the electron-cyclotron frequency. For the emission from the Sun _p / _e is probably greater than 0.3 and for 0.3 < _p / _e < 2 the emission can be either in the x-mode at the second harmonic or in the o- and/or z-modes at the fundamental. For higher _p / _e , the emission moves to higher harmonics of _e with the emission being predominately in the z-mode when _p / _e > 3.Proceedings of the Workshop on RadioContinua during Solar Flares, held at Duino (Trieste), Italy, 27–31 May, 1985.     

Околозвездньiе облака поданньiм ультрафиолетовьiх спектров свезл

, ii (2000–3000 Å) i . , i . i (. 2). i i i i + ( 7–10). ii (. 13). ii i i (, 2400 Å) (. 14 15). i i i , iu , i (. 1). i i ii i i . .     

A search for discrete gamma-ray sources of energy greater than 2×1012 eV

The results of the observations to search gamma-ray sources with the energy greater than 2×10¹² eV, which were made in Crimean Astrophysical Observatory during the years 1969–73 are presented. A technique of the detection of the EAS Cerenkov flashes was used.The quality of the data obtained is analysed. The criteria for the selection of the data free from meteorological variations are considered.It was shown that two objects, namely, Cyg X-3 and Cas -1, may be the sources of high-energy gamma quanta. It is probable that the object with the coordinates =05^h15^m, =+1° is the source of gamma-rays as well. An unidentified object Cas -1 is variable: gamma-ray flux was observed twice — in Sepember–October 1971 and in December 1972. It is possible that the flux from Cyg X-3 has a period of 4.8 hr.

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I I , I I , - >2.10¹² . I . I , I I, I ., - -1 Cyg -3- -I . , =0515 ·=+1° -.I -1 I: I J I- - 1971 1972 . Cyg -3, , - T=4.8 .

     

On the pulsation amplitude of cepheid variables

On the basis of more abundant data a relation logPV/logR for cepheid variables (Fernie, 1965) is constructed. A linear relation between logP V and logR for classical cepheids is found, which perhaps has a break at R=10R . On the logR/logP diagram thes-cepheids (Efremov, 1968) show a distinct sequence. Alls-cepheids present a relative variation of the radii R/R0.075. The existence of non-s-cepheids with R/R0.075 raises a point about the evolutionary place of these stars (see Efremov, 1968). One could suppose that cepheids with logP>1.1 pulsate in the first overtone.