The accuracy of observations of the Galilean satellites of Jupiter taken at the Abastumani Astrophysical Observatory of the Academy of Sciences of Georgia

The sets of photographic observations of the Galilean satellites of Jupiter taken at the Abastumani Astrophysical Observatory of the Academy of Sciences of Georgia are analyzed here. Positional observations of the system of Jupiter were made in the period from 1985 to 1994 with the use of the double Zeiss astrograph in order to determine the exact coordinates of Jupiter and its satellites. The accurate positions of the satellites and Jupiter itself, as well as their stellar (equatorial) coordinates relative to the stars of the currently available catalogs and the relative ??satellite ?? satellite?? coordinates were obtained from the observations. From the comparison of the observation results with the modern theories of motion of satellites, the accuracy in determining the positions of the satellites and Jupiter was analyzed. The results of observations are presented in the Pulkovo database of observations of Solar System bodies that is accessible to users at http://www.puldb.ru.     

The Italian Astrophysical Observatory in Antarctica: OASI

OASI (Infrared and Sub-mm Antarctic Observatory) is the first large telescope permanently installed in Antarctica. It is located close to the Italian Base in Antarctica (Terra Nova Bay Station, latitude: 74.39 S, longitude: 164.09 E). The OASI first light was received in December 1990 when the wobbling secondary mirror was mounted. The telescope is planned to be an open facility which can operate in the wavelengths range between 350 m and 3mm. The sky coverage from OASI goes down to a declination of about-35° for a 24 hours/day observing time.     

Stabilization of the spectrum position in the main stellar spectrograph of the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences

New results on the stability analysis study of the Main Stellar Spectrograph of the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences when it operated jointly with the CCD detection system on a laboratory source are reported. The spectrum is found to drift along the dispersion direction for several tenths of a pixel (several hundredths of angstrom) over a one-hour time scale. To prevent this drift (i.e., the spectrum shift)—a plane parallel glass plate is mounted; tilt angle of this plate varies as a function of the misalignment between the current and reference spectra of a hollow-cathode tube laboratory source. Operation of the spectrum stabilizer is described. The correction time is of about 1 minute, allowing the position of the spectrum to be maintained to within ±0.0006Å.     

IFU Unit in Scorpio-2 Focal Reducer for Integral-Field Spectroscopy on the 6-m Telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences

We describe the scheme and design features of the new IFU unit (Integral Field Unit) meant to perform integral-field spectroscopy as a part of SCORPIO-2 focal reducer, which is mounted in the prime focus of the 6-m telescope of the Special Astrophyscial Observatory of the Russian Academy of Sciences. The design of the unit is based on the principle of the formation of array spectra using a lens raster combined with optical fibers. The unit uses a rectangular raster consisting of 22×22 square 2-mm diameter lenses. The image of the object is transferred by an optical system with a 23^× magnification from the focal plane of the telescope to the plane of the lens raster. The image scale is —0.″75/lens and the field of view of the instrument has the size of 16.″5 × 16.—5². The raster also contains two extra 2 × 7 lens arrays to acquire the night-sky spectra whose images are offset by ±3′from the center. Optical fibers are used to transform micropupil images into two pseudoslits located at the IFU collimator entrance. When operating in the IFU mode a set of volume phase holographic gratings (VPHG) provides a spectral range of 4600–7300 Å and a resolution λ/δλ of 1040 to 2800. The quantum efficiency of SCORPIO-2 field spectroscopy is 6–13% depending on the grating employed.We describe the technique of data acquisition and reduction using IFU unit and report the results of test observations of the Seyfert galaxyMrk 78 performed on the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences.     

The Astrophysical Multimessenger Observatory Network (AMON)

We summarize the science opportunity, design elements, current and projected partner observatories, and anticipated science returns of the Astrophysical Multimessenger Observatory Network (AMON). AMON will link multiple current and future high-energy, multimessenger, and follow-up observatories together into a single network, enabling near real-time coincidence searches for multimessenger astrophysical transients and their electromagnetic counterparts. Candidate and high-confidence multimessenger transient events will be identified, characterized, and distributed as AMON alerts within the network and to interested external observers, leading to follow-up observations across the electromagnetic spectrum. In this way, AMON aims to evoke the discovery of multimessenger transients from within observatory subthreshold data streams and facilitate the exploitation of these transients for purposes of astronomy and fundamental physics. As a central hub of global multimessenger science, AMON will also enable cross-collaboration analyses of archival datasets in search of rare or exotic astrophysical phenomena.     

Solar physics at the Main Astronomical Observatory of the Ukrainian Academy of Sciences

A brief review of the research highlights at the Main Astronomical Observatory since 1968.     

Solar vector magnetograms of the Okayama Astrophysical Observatory

The title instrument is mounted on the 65 cm solar Coudé telescope at the Okayama observatory. Observation is usually of the Fei 5250 Å line. The data obtained are briefly described.Paper presented at the IAU Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984.     

Astrometric observations of planetary satellites at the Abastumani Astrophysical Observatory

We present and discuss the results of the astrometry project during which we observed the satellites of Mars, Jupiter, Saturn, Uranus, and Neptune at the Abastumani Astrophysical Observatory (Georgia) between 1983 and 1994. Observations at the Abastumani Observatory were performed with the double Zeiss astrograph (DZA: D/F = 400/3024 mm) and AZT-11 telescope (F = 16 m). We processed a large array of observations and determined exact coordinates of the planets and their satellites in a system of reference stars of modern catalogues as well as relative coordinates of the satellites. The results were compared with modern ephemerides using the MULTI-SAT software. The comparison enabled us to estimate the accuracy of observations (their random and systematic uncertainties) and the accuracy of modern theories of the motion of planets and their satellites. Random uncertainties of observations are estimated to be 0.10??C0.40?? for various objects and observational conditions. Observational results obtained for Uranus, Neptune and the satellites Titania and Oberon were shown to deviate appreciably and systematically from theories of their motion. The results of observations are presented in the Pulkovo database for Solar System bodies that is available at the website http://www.puldb.ru.     

Astrovirtel—From Archival Research to the Astrophysical Virtual Observatory

Given the high cost of modern astronomical observing facilities it is evident that efforts must be made to optimally exploit the data in order to maximize the return on investment. This concept was first implemented on a large scale for the Hubble Space Telescope, and has since been taken over for other space borne and large ground-based facilities. The European HST Science Data Archive is located at the European Southern Observatory (ESO). It has been extended to include data from ESO telescopes and instruments, especially the Very Large Telescope (VLT) and Wide Field Imager (WFI). It was thus natural to design the archive such that queries could be extended across its full content, regardless of the origin of the data. This constituted a first step toward a virtual observatory. The Astrovirtel program, first established in 1999–2000 with funding provided by the European Commission, makes it possible for scientists to use this facility for their investigations. At the same time it allowed us to establish science requirements for archive cross queries, and to define capabilities required for VO's. Recently the European Commission decided to provide the funding for the implementation of the Astrophysical Virtual Observatory (AVO). This will include several European observatories and scientific organizations. It is being developed in close coordination with the US National Virtual Observatory.     

One-meter Schmidt telescope of the Byurakan Astrophysical Observatory: New capabilities

In 2013–2015 the Laboratory of spectroscopy and photometry of extragalactic objects (LS-PEO) of the Special Astrophysical Observatory together with Armenian specialists upgraded the 1-m Schmidt telescope of the Byurakan Astrophysical Observatory of the National Academy of Sciences of Armenia. We completely redesigned the control system of the telescope: we replaced the actuating mechanisms, developed telescope control software, and made the guiding system. We reworked and prepared a 4k × 4k Apogee (USA) liquid-cooled CCD with RON ~ 11.1 e^?, a pixel size of 0.″868, and field of view of about 1□°, and in October 2015 mounted it in the focus of the telescope. The detector is equipped with a turret bearing 20 intermediate-band filters (FWHM = 250 Å) uniformly covering the 4000–9000 Å wavelength range, five broadband filters (u, g, r, i, z SDSS), and three narrow-band filters (5000 Å, 6560 Å and 6760 Å, FWHM = 100 Å). During the first year of test operation of the 1-m telescope we performed pilot observations within the framework of three programs: search for young stellar objects, AGNevolution, and stellar composition of galaxy disks.We confirmed the possibility of efficiently selecting of young objects using observations performed in narrow-band Hα and [SII] filters and the intermediate-band 7500 Å filter. Three-hours long exposures with SDSS g-, r-, and i-band filters allow us to reach the surface brightness level of 28^m/□″ when investigating the stellar content of galaxy disks for a sample of nine galaxies. We used observations performed with the 1-m telescope in five broadband (SDSS u, g, r, i, and z) and 15 intermediate-band filters (4000–7500 Å) to construct a sample of quasar candidates with 0.5 < z < 5 (330 objects) in about one-sq. degree SA68 field complete down to R_AB = 23^m. Spectroscopic observations of 29 objects (19.^m5 < R < 22^m) carried out at the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences confirmed the quasar nature of 28 objects.     

The asteroid ephemerides program at the U.S. Naval Observatory

The U.S. Naval Observatory has begun a program of ephemeris improvement and reference frame determination from the main belt asteroids. The program is, currently, starting out with a limited set of observations of the larger asteroids to determine the equator and equinox corrections for the USNO W1J00 transit circle observations catalog, and, if possible, improve the orbits of these asteroids based on this limited set of observations. For this project, transit circle observations of the Sun and the planets Mercury through Jupiter, are also being used to determine the equator, equinox, and ephemeris corrections, the next goal is to improve the orbits of the larger asteroids in the optical reference frame using observation series that cover a much longer period of time. This will allow the exploration of the differences between the dynamical reference frame based on radar observations of main belt asteroids and its relation with the optical reference frame. Other goals include the exploration of the mass distribution in the main asteroid belt from high precision observations, and the effect of this mass on the ephemerides of the major planets.     

Photometry of Io and Europa at the Crimean Astrophysical Observatory and reasons for differences between ground-based and space observations

Photometric observations of Jupiter’s moons Io and Europa in the spectral band V have been made at the Crimean Astrophysical Observatory for four years in order to construct their light curves reduced to a Solar phase angle of 6°. Comparison of these data with other ground-based observations shows good agreement. This study confirms why the moons that are close to Jupiter have a brighter leading hemisphere. The trailing hemispheres of Io and Europa, which are located in the rapidly rotating magnetic field of Jupiter, are exposed to bombardment by charged particles of the magnetic field. Leaving out of consideration the differences in brightness between the two hemispheres results in serious discrepancies between the space and ground-based photometry data.     

Optical Spectroscopy of Comet C/2000 WM1 (LINEAR) at the Guillermo Harro Astrophysical Observatory in Mexico

We present a preliminary analysis of medium resolution optical spectra of comet C/2000 WM1 (LINEAR) obtained on 22 November 2001. Theemission lines of the molecules C₂, C₃, CN, NH₂,H₂O⁺ and presumably CO (Asundi and triplet bands) and C₂ ^-were identified in these spectra. By analysing the brightnessdistributions of the C₂, C₃, CN emission lines along theslit of the spectrograph we determined some physical parameters of theseneutrals, such as their lifetimes and expansion velocities inthe coma. The Franck–Condon factors for the CO Asundi bands and C₂ ^- bands were calculated using a Morse potential model.     

The Editor-in-Chief of Our Journal M.Ya. Marov,Corresponding Member of the Russian Academy of Sciences,is Seventy

Solar System Research -     

虚拟天文台的科学意义

阐述了虚拟天文台的科学目标和一些基于虚拟天文台的成功范例及其优越性，以此显示创建虚拟天文台和构想新的研究范例的必要性，同时也说明虚拟天文台是由需求带动发展，并逐步由虚拟变为现实的研究途径。作为21世纪新的研究平台，虚拟天文台将在知识和技术等方面对天文学家提出新的挑战，提供新的机遇。