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1.
A first detailed period study of the eclipsing RS CVn-binary system RW Com is presented. A new period (P=0d.2373455) based on 223 minima is given. The O–C diagrams of RW Com have been presented for the first time. Types of ten minima have been corrected judging the period trend. Period changes in different portions of the O–C diagram (Figure 2) have been estimated. The total change in period (P/P) ranges from 5.5×10–7 to 6.4×10–6. Thus, P ranges from 1.3×10–7 d to 1.5×10–6 d. Numerous minima are available in the time interval 1967 to 1986. This part of the O–C diagram (Figure 2) shows a sinusoidal variation, thus, it is suspected that RW Com could be a three-body system. The period of variation due to third body appears to be nearly 16 years.  相似文献   

2.
On the basis of observational data for the absolute R and relative R/R amplitudes of variations in radius of galactic classical cepheids (55 stars from Balona and Stobie (1979) and 30 stars from Sollazzoet al. (1981)), four kinds of empirical linear relations are obtained: log(P V)–logR, logP–logR, log(P V)–log(R/R), and logP–log(R/R);P, R, and V are the pulsation periods, the mean stellar radii, and the amplitudes of light variations, respectively. Three groups of stars are considered: short-period cepheids (SPC)-with logP1.1; long-period cepheids (LPC)-with logP>1.1; and s-cepheids (sC). Both the R values and the R/R values increase withP andP V, for a given group of variables. A comparison is performed with our results obtained from data in other sources (Kurochkin, 1966; Gieren, 1982; etc.). The investigated relations can be applied for determining R and R/R of galactic classical cepheids, by using their observedP and V. All studied galactic classical cepheids have R/R<0.35, R<10R for SPC and 10R <R60R for LPC. The sC have smaller R and R/R values than other classical cepheids, at the same periods (the difference is about 2 times for R and 1.4–2.8 times for R/R); the studied sC have R/R in the range 0.025–0.075 and R in the range 1–3R (only Y Oph has R8R ).  相似文献   

3.
A new period (P=8d.439422) of the eclipsing binary system EI Cephei has been given, which is based on all available times of minima. Periods using Strohmeier's (1958) epoch have also been presented for the observations given by other investigators. Period based on only photoelectric minima comes out to be 8d.439336, which is lesser than the earlier periods given in the literature. O-C diagrams of EI Cephei have been presented for the first time, and period variations have been estimated in different portions of the O-C diagram (Figure 2) of EI Cephei. Strong period changes have occurred around the years 1959 and 1965. The total change in period (P/P) ranges from 6.7×10–5 to 4.3×10–4. Thus, P of the order of 10–3 d are present, which fact suggests that strong period variations are present in EI Cephei. However, periods given by various investigators show no systematic trend of period variations. The existence of a third body in the system could not be confirmed.  相似文献   

4.
It is shown that in the radiation era of the Universe spatial temperature fluctuations (T/T)<10–5 in the cosmic plasma lead to huge changes of the density up to (/)104. This effect results from the fact that the cosmic plasma in the radiation era can be considered as a general relativistic Boltzmann gas which is found in the very vincinity of equilibrium.  相似文献   

5.
A new period (P=1d.7175405) of the eclipsing binary system SZ Arietis has been presented. Period changes in different portions of the O-C diagram, with new period, have been estimated. The total change in period (P) ranges from 3.64×10–5 d to 4.24×10–4 d, which is appreciably large. However, leaving the unusual value, the average period change comes out to be of the order of 6×10–5 d. The period changes around the years 1903, 1943, and 1977 are apparent in the O-C diagrams. A sinusoidal variation is also visible in the O-C diagrams which indicates that SZ Ari may be a three-body system, having a period of nearly 66 years.  相似文献   

6.
The redshift c caused by the scattering of photons in the chromosphere of Canopus and in the interstellar matter is obtained from the measurements of wavelength, intensity and equivalent width of 191 spectral lines published in 1942. The result is c with a new radial velocityV r =–3.3±2.4 km s–1. The reliability of the results is briefly discussed.  相似文献   

7.
A detailed period study of the eclipsing binary system AW UMa is presented. A new period (P=0d.4387317) is given. Period changes in different portions of the O-C diagram, based on new period, have been estimated. The total change in period (P) ranges from 2.2×10–7 to 2.8×10–6 d, which is normal for AW UMa systems. Two distinct linear trends of period are visible in the O-C diagram. A third trend shows a new change in the period behaviour, which is yet to be confined.  相似文献   

8.
The work of Hill (1985a) on the low-degree 5 min eigenfrequency spectrum of the Sun based on differential radius observations combined with Doppler shift and total irradiance observations has been extended to include the work of Harvey and Duvall (1984) and Libbrecht and Zirin (1986). The differences between eigenfrequencies obtained in this analysis are compared to the predictions of asymptotic theory, and the deviations between observation and theory are observed to be 4 times larger than expected based on estimated accuracy of eigenfrequency determinations. These deviations are tested for departures from predictions of asymptotic theory which are quasi-periodic as a function of radial ordern and degreel. It is observed that the superposition of the seven distributions of frequency differences vsn obtained forl=0, ..., 6 generates an overdetermined quasi-periodic function when n/l=0.420±0.018 and v/l=–0.35 Hz in the superposition process. The probability that this quasi-periodic parent function is obtained from seven independent random distributions is estimated to be 1.2×10–7. Numerical experiments performed with theoretical eigenfrequency spectra demonstrate that the existence of a quasiperiodic behaviour in the superposed spectrum of frequency differences is physically plausible and that the parameters used in the superposition process are consistent with theory. One significant theoretical quasiperiodic behaviour is obtained for n/l=0.399. By comparing the properties of the observed quasi-periodic behaviour with those obtained in the numerical experiments, we infer that the location of the region which leads to the greatest departure from asymptotic theory predictions is 0.757±0.002 solar radii, which suggests that this region is connected with the transition zone between the radiative interior and the convection zone.  相似文献   

9.
An approximate metric is found which represents a sphere of matter embedded in a background of dust. The use of this metric in conjunction with the Friedmann equations gives values of for the three possible values ofk as +6×10–36 (k=+1), +3×10–35 (k=0), +10–36 (k=–1). These values depend on data regarding clusters of galaxies, and are probably accurate to within an order of magnitude given the correctness of the assumptions on which their derivation rests.  相似文献   

10.
For nine published high-resolution QSO spectra a correlation analysis of their L forest lines has been performed. The two-point correlation functions show some quasi-periodic structure of magnitude ||0.3. Their characteristic separation along the line-of-sight amounts to s 0=3×10–3 or to s 0=5×10–3 for =1 and 0.2, respectively. Especially the distribution of nearest neighbouring line positions in two close QSO pairs allows for the interpretation that the absorption clouds lie in sheet-like structures as predicted by the pancake theory. The correlation data contain some hints on metal absorbers within the forest of unidentified lines.  相似文献   

11.
Statistical analysis has been carried out of the relations between period and the ageP–t c, and the inclination of magnetic to rotation axis to the age –t cof pulsars have been done.Up to characteristic agest c=3×107 years the period increases as expected for magneto-dipole radiation energy lossesP=P m (1–exp(–t/ B ))1/n–1. Best-fitting parameters of this approximation are the time-scale of the magnetic moment decay B =4×106 years and breaking indexn=3.6. Fort c>3×107 years theP–t cdependence is significantly different.The inclination of magnetic to rotation axis decreases versus age, showing a secular alignment of the axis. But this decrease continues also only up tot c=3×107 years. Thus bothP–t cand –t cdependencies indicate that most of the pulsars of agest c>3×107 years are not evolutionary continuations of more younger ones, but apparently represent another population of pulsars, which differ by their genetic history or physical processes. This population includes all known millisecond pulsars. We suggest, that this population is a so-called recycled pulsar. The list of candidates of recycled pulsars is presented.A new evaluation of the inclination of the magnetic to the rotation axis for 105 pulsars is presented.  相似文献   

12.
The period study of the eclipsing binary DF Hya, based on up-to-date minima has been presented. The least-squares method has been applied to obtain a new period, which comes out to be 0 . d 3306017. Period changes are found around the years 1949, 1974, and 1982. Appreciable period changes are apparent around 1949 and 1974, the strongest being around 1974. The period changes (P) range from 0.46×10–6 d to 0.46×10–5 d, the average being 1.89×10–6 d. Such period changes are usual for a contact system, like DF Hya. Our results do not show increase in the time interval 1959–1985 as suggested by Zhanget al. (1989).  相似文献   

13.
Wheatland  M.S.  Litvinenko  Y.E. 《Solar physics》2002,211(1-2):255-274
The observed distribution of waiting times t between X-ray solar flares of greater than C1 class listed in the Geostationary Operational Environmental Satellite (GOES) catalog exhibits a power-law tail (t) for large waiting times (t>10hours). It is shown that the power-law index varies with the solar cycle. For the minimum phase of the cycle the index is =–1.4±0.1, and for the maximum phase of the cycle the index is –3.2±0.2. For all years 1975–2001, the index is –2.2±0.1. We present a simple theory to account for the observed waiting-time distributions in terms of a Poisson process with a time-varying rate (t). A common approximation of slow variation of the rate with respect to a waiting time is examined, and found to be valid for the GOES catalog events. Subject to this approximation the observed waiting-time distribution is determined by f(), the time distribution of the rate . If f() has a power-law form for low rates, the waiting time-distribution is predicted to have a power-law tail (t)–(3+) (>–3). Distributions f() are constructed from the GOES data. For the entire catalog a power-law index =–0.9±0.1 is found in the time distribution of rates for low rates (<0.1hours –1). For the maximum and minimum phases power-law indices =–0.1±0.5 and =–1.7±0.2, respectively, are observed. Hence, the Poisson theory together with the observed time distributions of the rate predict power-law tails in the waiting-time distributions with indices –2.2±0.1 (1975–2001), –2.9±0.5 (maximum phase) and –1.3±0.2 (minimum phase), consistent with the observations. These results suggest that the flaring rate varies in an intrinsically different way at solar maximum by comparison with solar minimum. The implications of these results for a recent model for flare statistics (Craig, 2001) and more generally for our understanding of the flare process are discussed.  相似文献   

14.
Detailed period study of the eclipsing binary ST Per is presented. A new period (P=2d.648339) is given. Period changes in different portions of the O-C diagram with a new period have been estimated. The total changes in period (P) ranges from 2.17×10–5d to 2.64×10–4d which is appreciably large. Sufficient number of minima in the time interval 1934 to 1985 for this system are available. Distinct increasing and decreasing trends are evident, the change in the tendency appears to have occurred around 1947. Sinusoidal variation is seen between cycles 7000–10000, which indicates that ST Per is a three-body system, the period of the third body being about 22 years. However, the sinusoidal variation is not perfectly symmetric in shape, therefore, it is suspected that ST Per is a four-(or multi-) body system.  相似文献   

15.
A semi-continuous hierarchy, (i.e., one in which there are galaxies outside clusters, clusters outside superclusters etc.), is examined using an expression of the field equations of general relativity in a form due to Podurets, Misner and Sharp. It is shown (a) that for a sufficiently populous hierarchy, the thinning factor( i+1/ i [r i /r i+1] is approximately equal to the exponentN in a continuous density law (=aR –N) provided (r i /r i+1)3-1; (b) that a hierarchical Universe will not look decidedly asymmetric to an observer like a human being because such salient observers live close to the densest elements of the hierarchy (viz stars), the probability of the Universe looking spherically symmetric (dipole anisotropy0.1 to such an observer being of order unity; (c) the existence of a semi-continuous or continuous hierarchy (Peebles) requires that 2 if galaxies, not presently bound to clusters were once members of such systems; (d) there are now in existence no less than ten arguments for believing 2, though recent number counts by Sandageet al. seem to be in contradiction to such a value; (e) Hubble's law, withH independent of distance, can be proved approximately in a relativistic hierarchy provided (i)N=2, (ii)2GM(R)/c 2 R1; (iii)Rc (iv)M0 in a system of massM, sizeR (f) Hubble's law holds also in a hierarchy with density jumps; (g)H100 km s–1 Mpc–1; (h) objects forming the stellar level of the hierarchy (in a cosmology of the Wilson type) must once have had 2GM/c 2 R1; (i) there is a finite pressurep=2Ga in all astrophysical systems (a=R N ,N2); (j) for the Galaxy, theory predictsp G7×10–12 dyn cm–2, observation givesp G5×10–12 dyn cm–2; (k) if the mass-defect (or excess binding energy) hypothesis is taken as a postulate, all non-collapsed astrophysical systems must be non-static, and any non-static, p0 systems must in any case be losing mass; (1) the predicted mass-loss rate from the Sun is 1012 g s–1, compared to 1011 g s–1 in the observed solar wind; (m) the mass-loss rates known by observation imply timescales of 5×109 years for the Sun and 1010 years for other astrophysical systems; (n) degenerate superdense objects composed of fermions must haveN-2 if they were ever at their Schwarzschild radii and comprised a finite numberN B of baryons; (o)N B1057N for degenerate fermion and boson systems; (p)285-4; (q) the metric coefficients for superdense bodies give equations of motion that imply equal maximum luminosities for all evolving superdense bodies (L max1059 erg s–1); (r) larger bodies have longer time-scales of energy radiation atL max (10–5 s for stars,1 h for QSO's) (s) expansion velocities are c soon after the initial loss of equilibrium in a superdense object; (t) if the density parametera(t) in aR –N isa=a (non-atomic constants of physicsc, G, A), andA, thenN=2; (u) N2 is necessary to giveMM at the stellar level of the hierarchy;(v) systems larger than, and including, galaxies must have formed by clumping of smaller systems and not (as advocated by Wertz and others) in a multiple big bang.  相似文献   

16.
It is shown that the cosmic matter gas after the recombination period can be regarded in a very good approximation as a general relativistic Boltzmann gas in the very vicinity of equilibrium. As a consequence, spatial temperature fluctuations (T/T)10–5 imply immense density fluctuations up to (p/p)105.  相似文献   

17.
We have observed the bipolar outflow source NGC 1333 (HH 7–11) in theJ=2–1 transition of12CO, and find evidence for a strong westerly termination of the red outflow lobe at a velocityV lsr 27 km s–1, together with maximal mean red-flow velocities v centred upon both the driving source SVS 13 and the westerly limit of the outflow zone. As a consequence, we propose a model for the source in which the red-shifted outflow is directly impinging upon a nearby molecular cloud, causing extensive surface erosion and/or diversion of the jet material.Paper presented at the 11th European regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.  相似文献   

18.
The electro-optic deflector as an analyzer of circular polarization in the photoelectric magnetograph is described. The electro-optic deflector consists of an electro-optic crystal and a polarizing beamsplitter. The plane bifurcation of this beamsplitter coincides with the spectrograph dispersion direction. The beamsplitter bifurcates a spectral line in two components. The distance between them is 0. The photometer slit is situated between these components. Both components of Zeeman splitting fall on the photometer slit but the distance between them varies from 0 + 2 H to 0 – 2 H (where H is the Zeeman splitting) with the electric voltage frequency applied to the electro-optic crystal. The intensity variations at the photometer slit are proportional to 4 H .  相似文献   

19.
Proton transfer and condensation reactions followed by dissociative electron recombination and charge transfer processes may yield a significant concentration of PO in interstellar clouds. Relevant terrestrial PO lines in the ultraviolet, infrared and microwave regions are listed in order to aid the detection of PO in interstellar clouds. Within the framework of Klein-Dunham potential, spontaneous emission rates and oscillator strengths of strong (v=0 sequence) beta bands of the PO molecule are estimated. For SgrB2 source, under optically thin case, each of the two strongest21/2,J=2.5–1.5 rotational transitions (108.998 GHz and 109.206 GHz) of PO would have antenna temperature less than 125 mk for beam efficiency0.6 and =0.7D (electric dipole moment of PO in thev=0 level of theX 2 state). For Orion molecular cloud, PO (4, 4.5, 5-3, 3.5, 4) (e, f) lines are excitable at 196.305 and 196.500 GHz and each line would have antenna temperature less than 110 mK.This work was partially supported by Fapesp and CNPq, Brazil, under contract numbers 80/1659-0 and 30.4076/77-FA01, respectively.  相似文献   

20.
A study is made of Lyman continuum observations of solar flares, using data obtained by the Harvard College Observatory EUV spectroheliometer on the Apollo Telescope Mount. We find that there are two main types of flare regions: an overall mean flare coincident with the H flare region, and transient Lyman continuum kernels which can be identified with the H and X-ray kernels observed by other authors. It is found that the ground level hydrogen population in flares is closer to LTE than in the quiet Sun and active regions, and that the level of Lyman continuum formation is lowered in the atmosphere from a mass column density m 5/sx 10–6 g cm–2 in the quiet Sun to m 3/sx 10–4 g cm–2 in the mean flare, and to m 10–3g cm–2 in kernels. From these results we derive the amount of chromospheric material evaporated into the high temperature region, which is found to be - 1015g, in agreement with observations of X-ray emission measures. A comparison is made between kernel observations and the theoretical predictions made by model heating calculations, available in the literature; significant discrepancies are found between observation and current particle-heating models.  相似文献   

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