Vol 60, No 9 (2016)

Two series of 22.2 and 36.8-GHz observations of 43 GHz-Peaked Spectrum (GPS) radio sources from the Planck survey have been carried out using the 22-m radio telescope of the Crimean Astrophysical Observatory in 2014–2015, with the aim of studying the variability of these sources. The interval between the two series of observations was about nine months. These data were analyzed together with the Planck data at frequencies from 20 to 143 GHz. The fraction of quasars among GPS sources grows to 90% at millimeter wavelengths, compared to 1.4% at decimeter wavelengths. The growth in the variability indices of Planck GPS sources is not as sharp as that observed at decimeter and centimeter wavelengths, and remains at a level of about 30% at millimeter wavelengths. This supports the view that GPS sources are not strongly variable, compared to other types of Active Galactic Nuclei (AGNs). A mean spectrumfor the GPS radio sources has been obtained, which is shallower at low frequencies and steeper at high frequencies atmillimeter wavelengths than at decimeter and centimeterwavelengths. These properties of the GPS spectra at millimeter wavelengths testify to the compactness of these sources and the dense, inhomogeneous nature of the medium in which they are located. This also indirectly suggests that these objects are young and that their active states have short lifetimes.

Orbital-period variations of the Algol-type eclipsing binaries RW CrB and AO Ser are analyzed. It is shown that the period variations of these systems are due mainly to the light-time effect due to the eclipsing binary’s motion in its long-period orbit. The period variations of RW CrB are reproduced by motion of the eclipsing binary with a period of 55.8 years around a third body with the mass M₃ > 0.36M⊙. The period variations of AO Ser can be reproduced either solely with the light-time effect, or by a superposition of the light-time effect and a slow secular decrease in the period. In the former case, the period of the long-period orbit is 111.5 years; in the latter case, it is 108 years. Both cases imply the same mass for the third body in the AO Ser system: M₃ > 0.35M⊙. The residual small-amplitude orbitalperiod variations of the two systems can be due to magnetic cycles.

A new series of yearly-mean relative sunspot numbers SN₂ that has been extrapolated into the past (to 1610) is presented. The Kislovodsk series with the scale factor b = 1.0094 ± 0.0059 represents a reasonable continuation of the mean-monthly and mean-yearly total sunspot areas of the Greenwich series after 1976. The second maximum of the 24th solar-activity cycle was not anomalously low, and was no lower than 6 of the past 13 cycles. A series A₂ of values for the total sunspot area in 1610–2015 has been constructed, and is complementary to new versions of the series of the relative number of sunspots SN₂ and the number of sunspot groups GN₂. When needed, this series can be reduced to yield a quantity having a clear physical meaning—the spot absolute magnetic flux Φ_Σ(t)[Mx] = 2.16 × 10¹⁹A(t) [mvh]. The maximum sunspot area during the Maunder minimum is much higher in the new series compared to the previous version. This at least partially supports the validity of arguments that cast doubt on the anomalously low ampltude of the solar cycles during the Maunder minimum that has been assumed by many researchers earlier.

A critical review of determinations of the number of spicules is presented, and the role of both classical and Type 2 spicules in heating and mass balance in the corona is considered. The total number of Type 2 spicules is determined, together with the upward fluxes of energy and mass to which they give rise. The total number of Type 2 spicules on the solar surface is found to be ~10⁵, close to values obtained in other studies. The associated particle flux toward the corona is 2.5 × 10¹⁴ cm⁻² s⁻¹, an order of magnitude lower than the corresponding flux for classical spicules. The associated energy flux is 10⁴ erg cm⁻² s⁻¹, an order of magnaitude lower than estimates obtained in other studies. The results indicate that Type 2 spicules can supply the mass lost from the corona, but are not able to fully explain coronal energy losses.

Two major characteristics of modern astronomy are multiwavelength (MW) studies (fromγ-ray to radio) and big data (data acquisition, storage and analysis). Present astronomical databases and archives contain billions of objects observed at various wavelengths, both galactic and extragalactic, and the vast amount of data on them allows new studies and discoveries. Astronomers deal with big numbers. Surveys are the main source for discovery of astronomical objects and accumulation of observational data for further analysis, interpretation, and achieving scientific results. We review the main characteristics of astronomical surveys, compare photographic and digital eras of astronomical studies (including the development of wide-field observations), describe the present state of MW surveys, and discuss the Big Data in astronomy and related topics of Virtual Observatories and Computational Astrophysics. The review includes many numbers and data that can be compared to have a possibly overall understanding on the Universe, cosmic numbers and their relationship to modern computational facilities.