Next: The Chemical Evolution of Up: Stellar Astrophysics Previous: Stellar Astrophysics . Simon Jeffery has used a novel camera attached to the William Herschel Telescope (WHT) to obtain the best light curves ever obtained for pulsating subdwarf B stars. These stars pulsate non-radially in several modes with different frequencies and enable astronomers to establish their overall properties and internal structure with unusual precision. ...

... Contact A Problem of an estimation of accuracy of the asteroid CCD observations . The Minor Planet Center supported by the Interntional Astronomical Union is the main office for keeping observational data of the small Solar System bodies and their investigations. ... At Pulkovo Observatory we are estimating an accuracy of the CCD asteroid observations obtained by amateurs and professional astronomers all over the World using the MPC database. ...

This is the homepage of Andrew Fruchter, an astronomer on the staff of the Space Telescope Science Institute . ... Here you can look at an HST images of the optical counterparts of gamma-ray bursts and their host galaxies. ... Therefore, substantial information on the fine scale structure of objects can be obtained by offsetting the pointing of the telescope between exposures and then combining these "dithered" exposures into a single image. ...

... 13, Moscow 119992, Russian Federation, e-mail: busarev@sai.msu.ru; 2 Research Institute Crimean Astrophysical Observatory, p/o Nauchnyi, Crimea 334413, Ukraine, e-mail: prok@crao.crimea.ua Summary: We propose a combined method of astronomical investigations of small or distant planets incorporating registration of a set of integral spectra of an object and their frequency analysis. ... An application of the method is shown on example of asteroid 21 Lutetia. ... 6] Busarev V. V. (2002), Solar Sys. ...

Next: IPCS observations and data Up: Spectral survey of Case Previous: The sample description . The observations were carried out with the 6m telescope of the Special Astrophysical Observatory of Russian Academy of Sciences (SAO RAS) in the period from December 1992 to October 1996. ... 1986 ]). Since January 1996 we used for registration Tektronix CCD 1024 1024 provided by Astrophysical Institute Potsdam (AIP, Germany) in the frame of mutual cooperation between AIP and SAO RAS. ...

... In order to compare the number of different evolutionary stages obtained and X-ray luminosity of the chosen X-ray sources with the observed galactic values we use the sum of C/O+O/C , where C and O are the calculated and observed values of a given binary type, respectively. If we make comparison for a number of different binary species (for example, we compare the number of CV, number of X-ray pulsars,   total X-ray luminosity of LMXB, etc.), we write this criterion in the form: . ...

Databases (NSDC) of the Natural Planetary Satellites. ... NSDC: Database of astrometric observations of Natural Planetary Satellites . ... They are thoroughly looking for observations in different sources, creating their owndatabases which are then mostly inaccessible to other researchers. ... In the file "content" with explications, the reference is given to the data source as well as the bibliographic reference. ... Data sources. ... Why a specific bibliographic database for Natural satellites? ...

To main of Laboratory . The research work and design of optical and optical-electronic devices are carries out by laboratory staff: . ... Lens: . ... In the layout 1 prism systems perform functions of dispersive element, corrector of aberrations, optical reducer. ... Spectral range 200 - 400 nm; . ... Back Forward . ... The main corrector's function are compensation of field aberrations of the main spherical mirror of a telescope (diameter of 600 mm, f'=1200 mm) and increase aperture ratio. ...

For the calibration of RATAN-600 data you will need to Download Nobeyama Fluxes (1, 2, 3.75, 9.4, 17 GHz): year 1999 2000 2001 2002 2003 . Brief description of Work Scan . Main functions of processing, realized in the program are: . ... Correction of various (not fatal) defects of data; . ... Calculating of the lower enveloping curve or an average scan from observations data for a few days; . ... COMMENT This table contains the set (TFIELDS) of 1-dimensional (TFORM# . ... AZIMUTH = 'float' / . ...

... Previous: Generalized Linear Multi-Frequency Imaging in VLBI . ... At Astronomical Observatory of Valencia University (OAUV), CCD observations of asteroids and big planets satellites are obtained since 2001 with a big format camera and several telescopes. ... Software for comparison of single and overlapped CCD fields obtained at different epochs has been developed. ... After images measurement in CCD field, catalogue stars are identified and adjusted with images. ...

Atmospheric influence on the different radio-engineering system functioning . ESTIMATION OF ATMOSPHERIC OPTICAL CHARACTERISTICS AND REMOTELY SANSED IMAGE CORRECTION . ... Direct transmittance estimation results for 12 channels of the spectrometer CHRIS. ... We have managed to develop a direct method of estimating the discrete Normalized Atmospheric Point Spread Function (NAPSF) from available images alone, not using any external sources of information about the atmosphere. ... IRE RAS 1996-20 11 ...

... We will consider the rms, (K), for observations with a receiver of system temperature, T , frequency resolution, per polarization, and total integration time per observing cycle, . ... For ``in-band'' frequency switching, the line under investigation is always in the observing band. ... Position Switching or ``Out-of-Band'' Frequency Switching: Here the line is only observed for one half of the time, with noise being present all of the time. ...

Masses of asteroids 10 Hygiea and 152 Atala obtained by the dynamical method . ... Masses of asteroids 10 Hygiea and 152 Atala have been obtained by the dynamical method. ... m 152 = 1.34 0.27 (10 -11 Sun )]. ... Very Long Baseline Interferometry (VLBI), Small Solar System Body (SSSB), mass of asteroids 10 Hygiea, mass of asteroids 152 Atala, the dynamical method, perturbing asteroids, the additional acceleration, the Yarkovsky effect, elimination of erroneous observations, optical observations. ...

IBIS Data Analysis . ... IBIS . ... Flat Fielding - Introduction . The images obtained by IBIS will have intensity variations across the field of view that are not due to the solar image, but rather caused by instrumental effects that alter the observed intensity in each point of the field of view. ... IBIS Flat Fielding Techniques . ... Therefore, it is desirable to obtain the flat field measurements center on a point along the equator near the heliographic center of the solar disk. ...

... the time of observation . ... Observing the Changing Position of the Sun To Establish Cardinal Directions . ... Observations of the Sun's apparent movement across the sky and its pattern of rising and setting in the east and west horizon helped to establish the cardinal directions. ... The final stage of the Sun's return was marked by the observation that the Sun had reached its highest altitude when the full width of your mitted hand could fill the gap between the Sun and the horizon. ...

These observations are aimed at fully charactering FORS1 photometric system (UBVRI zero-points, color-terms and extinction coefficients) for the Tektronix 2048x2048 pixel CCD (24µm px) . To this aim, the two Landolt/Stetson photometric fields SA95 and SA101 will be observed on a number of epochs and at different airmasses during February and March 2007. ... SA101 . ... OBs for SA101 have to be observed during evenigh twilight (exceptions are expected for the second half of March) . ...

Planetary nebulae are the remnants of low-to-middle mass stars. ... These so-called post-AGB stars are in an intermediate stage of evolution between the AGB and planetary nebulae. ... By studying the post-AGB stars we may be able to determine what causes the complicated structures seen in some planetary nebulae. To investigate this question, we have selected a well-defined sample of 86 post-AGB stars from a previous study of OH 1612-MHz maser sources in the Galactic plane (Sevenster et al., ...

... Variation of systematic errors for USNO A2 (in mas per year) 23 .914 0.082 0.250 0.418 0.586 0.753 0.921 1.089 1.257 1.425 1.593 4 4. 3. 3. 3. 3. 3. 3. 3. 3. 3. 15 ± 7± 1± 3± 3± 10 ± 10 ± 11 ± 6± 10 ± 12 ± and their errors USNO UCAC USNO UCAC A2.0 2 3 B1.0 4 (1998) (2006) (2003) (2012) 37 27 11 4 732 529 778 501 050 078 775 387 (34 610 829) (17 209 447) (9 744 401) () Distribution of observations ( ...

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... October 19, 1996 . Lalande 21185: The Nearest Planetary System? ... Explanation: What's the closest extrasolar planetary system ? It may well be planets of the dim red dwarf star cataloged as Lalande 21185 -- a mere 8 light years distant. ... Our own planetary system would be detectable by such a technique .. ... Nevertheless, the existence of a planetary system so near our own suggests the intriguing possibility that planets are common in our galaxy. ... About APOD | ...