Polarization and brightness of the blazar S5 0716+714 in 1991–2004

We investigate the photometric and polarimetric behavior of the blazar S5 0716+714 based on the observations carried out in 1991–2004 at the 125-cm Crimean Astrophysical Observatory telescope (AZT11) with a photopolarimeter that allows simultaneous polarization and brightness measurements to be made in the U BV RI bands. We also provide the U BV photometry for the blazar obtained in 2000–2009 with a 60-cm telescope at the Crimean Station of the Sternberg Astronomical Institute. The pattern of flux variability and the correlation between the brightness, color, and polarization variations have been investigated. In this time interval the blazar showed a significant brightness and polarization variability similar to noise processes.     

Far-infrared brightness temperature of Saturn's disk and rings

We present far-infrared observations of Saturn in the wavelength band 76–116 μm, using a balloon-borne 75-cm telescope launched on 10 December 1980 from Hyderabad, India, when B′, the Saturnicentric latitude of the Sun, was 4°.3. Normalizing with respect to Jupiter, we find the average brightness temperature of the disk-ring system to be 90 ± 3° K. Correcting for the contribution from rings using experimental information on the brightness temperature of rings at 20 μm, we find T_D, the brightness temperature of the disk, to be 96.9 ± 3.5° K. The systematic errors and the correction for the ring contribution are small for our observations. We, therefore, make use of our estimate of T_D and earlier observations of Saturn when contribution from the rings was large and find that for wavelengths greater than 50 μm, there is a small reduction in the ring brightness temperature as compared to that at 20 μm.     

Observations of Solar EUV Radiation with the CORONAS-F/SPIRIT and SOHO/EIT Instruments

The SPIRIT complex onboard the CORONAS-F satellite has routinely imaged the Sun in the 171, 175, 195, 284, and 304 Å spectral bands since August 2001. The complex incorporates two telescopes. The Ritchey-Chretien telescope operates in the 171, 195, 284, and 304 Å bands and has an objective similar to that of the SOHO/EIT instrument. The Herschel telescope obtains solar images synchronously in the 175 and 304 Å bands with two multilayer-coated parabolic mirrors. The SPIRIT program includes synoptic observations, studies of the dynamics of various structures on the solar disk and in the corona up to 5 solar radii, and coordinated observations with other spaceborne and ground-based telescopes. In particular, in the period 2002–2003, synoptic observations with the SPIRIT Ritchey-Chretien telescope were coordinated with regular 6-hour SOHO/EIT observations. Since June 2003, when EIT data were temporarily absent (SOHO keyholes), the SPIRIT telescope has performed synoptic observations at a wavelength of 175 A. These data were used by the Solar Influence Data Analysis Center (SIDC) at the Royal Observatory of Belgium for an early space weather forecast. We analyze the photometric and spectral parameters of the SPIRIT and EIT instruments and compare the integrated (over the solar disk) EUV fluxes using solar images obtained with these instruments during the CORONAS-F flight from August 2001 through December 2003.     

Photometric observations of Cepheids from the ASAS-3 catalog: Photoelectric <Emphasis Type="Italic">BV I</Emphasis><Subscript>c</Subscript> observations of 46 low-amplitude Cepheids

From December 2006 to January 2008, we performed 1699 BV I _c observations for 46 low-amplitude Cepheids discovered in the course of the ASAS project using the 76-cm telescope of the South-African Astronomical Observatory (SAAO). We provide the tables of observations and V light and B-V and V-I _c color curves. These new observations, along with data from the ASAS-3 catalog, have been used to improve the elements of the light variations. Our data allow the number of known Galactic low-amplitude Cepheids to be almost doubled. This makes it possible to increase the number of distance indicators suitable for studying the structure of the inner Galactic arms by almost 15%.     

A search for natural or artificial objects located at the Earth-Moon libration points

Photographs in the vicinity of the Earth-Moon triangular libration points L4 and L5, and of the solar-synchronized positions in the associated halo orbits (A. A. Kamel, 1969, Ph.D. dissertation, Stanford University), were made during August–September 1979, using the 30-in Cassegrain telescope at Leuschner Observatory, Lafayette, California. An effective 2° square field was covered at each position. No discrete objects, either natural or artificial, were found. The detection limit was about 14th magnitude. The present work extends traditional SETI observations to include the search for interstellar probes (R. A. Freitas, Jr., 1980a, J. Brit. Interplanet. Soc.33, 95–100).     

Investigation of Nova Cygni 1975 (V 1500) at Abastumani. I. Photographic Observations of Spectra

On the night of August 30/31, 1975, one of the authors discovered a nova in the constellation Cygnus. Spectroscopic observations of the nova were made with a 70-cm meniscus telescope, using a 72-cm, 8°, objective prism and a diffraction spectrograph mounted at the Cassegrain focus. The radial velocity of expansion of the nova's shell turned out to be about 2000 km/sec and its mass was on the order of 10^-5 M and had a tendency to increase with time; we estimated the emission energy to be 5·10⁴⁴ erg and the kinetic energy of the shell to be 10⁴⁵ erg, while the electron temperature in the shell is 5000 K.     

Study of the RATAN-600 power beam pattern and antenna effective area based on deep sky survey data

The power beam pattern and antenna effective area of the RATAN-600 radio telescope are analyzed based on source samples observed during the 7.6-cm sky surveys preformed in 1980, 1988, 1990, 1991, 1993, 1994, and 1999. The surveys were made with the Northern sector of the RATAN-600 at the same declination as the COLD experiment (δ ∼ 5°). Experimental power beam patterns derived from the survey data are compared with the computed patterns. The r.m.s. deviation of the experimental data from the corresponding computed values averaged over all years is (0.19 − 0.23) ± 0.02. The vertical pattern of the 1980 survey is offset by about 1t’ with respect to the central horizontal section. The patterns obtained from the data for other years are symmetric within the measurement errors. The mean antenna effective area averaged over all years except 1993 is 803 ± 88 m². The behavior of both the beam pattern and effective telescope surface areas was stable from 1980 through 1999     

Photometric observations of Cepheids from the ASAS-3 catalog: Photoelectric <Emphasis Type="Italic">BV I</Emphasis><Subscript>c</Subscript> observations of 33 classical Cepheids

Cepheids, the principal distance indicators, point to the existence of two inner Galactic spiral arms in the immediate solar neighborhood (within 5 kpc). However, the available Cepheids are clearly insufficient for a detailed study of the structure of these arms. Fortunately, southern-sky monitoring (the ASAS project) has led to the discovery of many new variable stars, more than one thousand of which have been identified as possible Cepheids. To improve the classification and to construct reliable light curves for new Cepheids, we have begun their regular photometric observations. Here, we present the first results: 1192 photoelectricBV I _c observations were performed for 33 classical Cepheidswith the 76-cm telescope of the South-African Astronomical Observatory (SAAO, the South-African Republic) from December 2006 to January 2008. We provide tables of observations and V light and B-V and V-I _c color curves. The new observations together with ASAS-3 data have been used to improve the elements of the light variations.     

CCD BVI c observations of Cepheids

In 2008–2013, we obtained 11333 CCD BVI _c frames for 57 Cepheids from the General Catalogue of Variable Stars. We performed our observations with the 76-cm telescope of the South African Astronomical Observatory (SAAO, South Africa) and the 40-cm telescope of the Cerro Armazones Astronomical Observatory of the Universidad Católica del Norte (OCA, Chile) using the SBIG ST-10XME CCD camera. The tables of observations, the plots of light curves, and the current light elements are presented. Comparison of our light curves with those constructed from photoelectric observations shows that the differences between their mean magnitudes exceed 0?05 in 20% of the cases. This suggests the necessity of performing CCD observations for all Cepheids.     

Observations of cosmic gamma-ray bursts with the main detector of the SIGMA telescope onboard the Granat Observatory

We present the observations of cosmic gamma-ray bursts (GRBs) with the main detector of the SIGMA telescope onboard the Granat Observatory from January 1990 through September 1994. The observations were carried out in the energy range 35–1300 keV. We detected 36 GRBs and 31 high-energy solar flares during this period. No GRB fell within the main field of view; they were all recorded by the “secondary optics” of the telescope. The SIGMA telescope recorded relatively bright bursts with peak fluxes of 10^?6–10^?4 erg s^?1 cm^?2 in the 100–500-keV energy band. Stable detector background allows the long-term variability of GRB sources on a time scale of ～1000 s to be studied. The results of our search for early afterglows of GRBs are presented. The flux averaged over all bursts in the interval 100–800 s after the main event is 0.36±0.14 counts s^?(35–300 keV), suggesting that there is soft gamma-ray emission on this time scale after a considerable number of GRBs.     

High-resolution observations of the 6815-Å band of methane in the major planets

High-resolution (0.1-Å) spectra of the 6815-Å band of methane are presented for Jupiter, Saturn, Uranus, and Neptune. Spectra for Uranus, Neptune, and the equatorial region of Saturn were acquired with the SPIFI (W. H. Smith, T. R. Hicks, and J. P. Born (1978). Proceedings of the 4th International Colloquium on Astrophysics, Triest, July 3–7, 1978. pp. 593–599) at the 2.2-m telescope of the Mauna Kea Observatory during May and June 1980. Additional spectra were obtained for Jupiter and the northern temperate and polar regions of Saturn in December 1980 and January 1981 from Kitt Peak National Observatory's McMath Solar Telescope. The spectra show a dichotomy in strength of methane absorption between Jupiter-Saturn and Uranus-Neptune. A simple model analysis, based on homogeneous scattering models, is unable to resolve whether this dichotomy is due to an actual increase in the methane mixing ratio with solar distance or to the temperature dependence of line strengths and absorption pathlengths in these atmospheres. If the rotational quantum number for the prominent 6818.9-Å feature is J < 4, then significant aerosol extinction must exist within the visibly accessible portion of Uranus' atmosphere for the methane mixing ratio to be greater than the solar value.     

A method for the determination of the lithium abundance in sunspots: Observations for 2011

Sunspot spectra for LiI 6708Å lines and for several FeI and CaI lines were obtained. Observations were performed in January and in August, 2011 using the TST-2 telescope with a charge-coupled camera at the Crimean Astrophysical Observatory. The sunspot models were calculated by using the observing profiles of FeI and CaI lines. Lithium abundance was determined by using the calculated sunspot models and LiI 6708Å observed profiles; this equals log(N _Li) = 0.98 and 0.95 (in the scale logA(H) = 12.0).     

Geometric Localization of CMEs in 3D Space Using STEREO Beacon Data: First Results

The geometric localization technique (Pizzo and Biesecker, Geophys. Res. Lett. 31, 21802, 2004) can readily be used with Solar Terrestrial Relations Observatory (STEREO) Space Weather Beacon data to observe coronal mass ejection (CME) propagation within three-dimensional space in near-real time. This technique is based upon simple triangulation concepts and utilizes a series of lines of sight from two space-based observatories to determine gross characteristics of CMEs, such as location and velocity. Since this work is aimed at space weather applications, the emphasis is on use of COR2 coronagraph data, which has a field of view from 2.5R _⊙ to 15R _⊙; this spatial coverage allows us to observe the early temporal development of a CME, and hence to calculate its velocity, even for very fast CMEs. We apply this technique to highly-compressed COR2 beacon images for several CMEs at various spacecraft separation angles: 21 August 2007, when the separation angle between the two spacecraft was 26°; 31 December 2007 and 2 January 2008, when the separation angle was 44°; and 17 October 2008, when the spacecraft separation was 79°. We present results on the speed and direction of propagation for these events and discuss the error associated with this technique. We also compare our results to the two-dimensional plane-of-sky speeds calculated from STEREO and SOHO.     

Observations of the OH radical in comets at 18 cm wavelength

We present recent observations of the OH radical at λ 18 cm with the Nançay radio telescope in comets Meier (1978 XXI), Bradfield (1979 X), Meier (1980q), P/Encke (1980), and Bradfield (1980t). The analysis of the OH radio line shape is a powerful tool to study the kinematics of the coma. The expansion velocity of the OH molecules is found to be ≈1.5 km sec^?1 at r_h = 1 AU, and decreases with increasing heliocentric distance. The line profile is generally asymmetric, which demonstrates the Greenstein effect on the fluorescent excitation mechanism and/or anisotropic outgassing of the nucleus. In several cases, especially for comet Meier (1978 XXI), an asymmetry is also found in the east-west brightness distribution of the OH line, showing again the Greenstein effect and/or anisotropic outgassing. An excitation model by uv pumping and fluorescence of the OH radical, which agrees with the observations at least in the first order, and the application of Haser's model lead to the production rate of the parent molecule of OH. There is a close correlation between this gas production rate and the visual brightness of the comet. Our estimates of gas production rates are smaller than or equal to those obtained from uv measurements, but both radio and uv estimates depend heavily on the parameters used in Haser's models.     

Photometric and spectroscopic evolution of the symbiotic nova V1016 Cygni after its outburst

We have constructed the light curves of the symbiotic nova V1016 Cyg for the period 1971–2007 in a homogeneous photometric system close to UBV using our observations with the Zeiss-600 SAI telescope. Based on the observational data obtained with the 125-cm SAI telescope in 2000–2007, we have performed absolute spectrophotometry of the star in the range λ3700–9300 Å. The derived line intensities are compared with the data of other authors in the preceding years (1965–1988). The behavior of nebular lines showed the variations in electron density and, probably, electron temperature in the [OIII] emission region caused by a variable stellar wind from the hot component. All the available observations of the star confirm the theoretical conclusion that the nova-like outburst of V1016 Cyg was produced by a thermonuclear flash in the accreted envelope of a white dwarf.     

Moving Dipolar Features in an Emerging Flux Region

Solar Physics - On 25 January, 2000, we observed active region NOAA&;nbsp;8844 with the Flare Genesis Experiment (FGE), a balloon-borne observatory with an 80-cm solar telescope. FGE was...     

Observations of Saturn's inner satellites and the orbit of Janus in 1980

Systematic observations of faint satellites were conducted at Pic-du-Midi with a focal coronograph from 1980 March 20 to 24, during which 150 exposures covering 17 hr were obtained; in addition, the 1966 discovery plates of satellites S10 Janus were reexamined together with other 1966 observations. Janus had its greatest eastern elongation on 1966 December 15.720 (±0.003) + light time, at a distance of 2.53R_eq. It is recognized that some of the observations thought to be 1966 S2 were in fact reobservations of Janus a few days after its discovery. Among the 1980 observations, differences in magnitudes indicate that is satellite 1980 S1 which corresponds to Janus; its greatest eastern elongation was observed on March 23.876 (±0.002) + light time. Subjected to corrections for librations, the mean period over the past 14 years has most probably one of three values: P₁ = 0.69458 day, P₂ = 06.9448 day or P₃ = 0.69438 day. The fainter satellite, S11, which is also 1980 S3, gravitates in an orbit similar to that of Janus and was leading it by +190° in March 1980; this difference of longitude was +224° in December 1966. An object of magnitude 15–16 was seen not detached from the ring; it could be a condensation in the external part of the rings or an additional faint inner satellite.     

Observations of Minor Planets

We represent 266 positions of 77 minor planets determined from plates taken in 1972 and in 1979–1980 with the Schmidt telescope 1340/2000/4000 of KARL SCHWARZSCHILD Observatory Tautenburg.     

The solar flare catalog in the low-energy gamma-ray range based on the AVS-F instrument data onboard the CORONAS-F satellite in 2001–2005

The AVS-F apparatus onboard the CORONAS-F satellite (operated from July 31, 2001, to December 6, 2005) was intended for investigation of solar hard X-ray and gamma-ray radiation and for registration of gamma-ray bursts. The AVS-F apparatus constitutes a system for processing the data from two detectors: SONG-D (a CsI(Tl) scintillation detector 200 mm in diameter and 100 mm in height, fully surrounded by plastic anticoincidence shield) and RPS-1 (a solid state CdTe detector 4.9 mm × 4.9 mm in size). Over 60 solar flares stronger than M1.0 class by GOES classification were registered during the period from August 2001 to February 2005. Most flares showed gamma-ray emission during the periods when a rise in the X-ray flux was observed by the GOES instruments. Some flares produced gamma-rays only at maximum X-ray emission; for some flares, the durations of gamma-ray and X-ray emissions were the same. Up to six complexes of spectral lines were detected in some solar flares. The AVS-F instrument analyzes temporal profiles of low-energy gamma-ray emission with a temporal resolution of 1 ms within the first 4.096 seconds of solar flares. The preliminary analysis of such temporal profiles for seven solar flares revealed time regularities with scales from 7 to 35 ms in the 0.1-to 20-MeV energy range only for the flare of January 20, 2005, at a confidence level of 99%.     

AKARI: space infrared cooled telescope

AKARI, formerly known as ASTRO-F, is the second Japanese space mission to perform infrared astronomical observations. AKARI was launched on 21 February 2006 (UT) and brought into a sun-synchronous polar orbit at an altitude of 700 km by a JAXA M-V rocket. AKARI has a telescope with a primary-mirror aperture size of 685 mm together with two focal-plane instruments on board: the Infrared Camera (IRC), which covers the spectral range 2–26 μm and the Far-Infrared Surveyor (FIS), which operates in the range 50–180 μm. The telescope mirrors are made of sandwich-type silicon carbide, specially developed for AKARI. The focal-plane instruments and the telescope are cooled by a unique cryogenic system that kept the telescope at 6K for 550 days with 180 l super-fluid liquid Helium (LHe) with the help of mechanical coolers on board. Despite the small telescope size, the cold environment and the state-of-the-art detectors enable very sensitive observations at infrared wavelengths. To take advantage of the characteristics of the sun-synchronous polar orbit, AKARI performed an all-sky survey during the LHe holding period in four far-infrared bands with FIS and two mid-infrared bands with IRC, which surpasses the IRAS survey made in 1983 in sensitivity, spatial resolution, and spectral coverage. AKARI also made over 5,000 pointing observations at given targets in the sky for approximately 10 min each, for deep imaging and spectroscopy from 2 to 180 μm during the LHe holding period. The LHe ran out on 26 August 2007, since which date the telescope and instrument are still kept around 40K by the mechanical cooler on board, and near-infrared imaging and spectroscopic observations with IRC are now being continued in pointing mode.