Twilight observations with MASS/DIMM B. Safonov Sternberg Astronomical Institute Moscow State University Comprehensive Characterization of Astronomical Sites, 2010 B. Safonov (Moscow State University) Twilight observations with MASS/DIMM SITE 2010 1 / 17 Why observe in twilight with MASS/DIMM? ... ASM includes 3 devices sensitive to background: guider, DIMM and MASS. B. Safonov (Moscow State University) Twilight observations with MASS/DIMM SITE 2010 2 / 17 Background in guider. ...

... Exposure Time Calculator (ETC) . ... ESO - Public Surveys . ... the recommended values to use for DIT, . ... Detector on-chip integration (DIT): seconds. to your chosen value - a separate page gives recommended values to use for DIT - for modes 1 and 2 below you may wish to start with the maximum recommended values as these will minimize the effect of read noise (a total object exposure of Y secs with DIT=X secs will produce Y/X lots of read noise) and give you a lower limit on the time needed. ...

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? ...

spaceweb@oulu.fi - last update: 27 November 1998, 1900 UT (RR) . Tailward fast plasma flows with dipolar Bz signatures (north-then-south turning of B) observed within plasma sheet are called plasmoids (e.g., Hones et al., ... Most plasmoids have also helical magnetic field structures (large By fields), called "flux ropes" (Hughes and Sibeck, 1987; Slavin et al., ... 1998). ... Observations of plasmoids are highly correlated with substorm onsets (Moldwin and Hughes, 1993; Nagai et al., ... Lett. ...

Diffuse interstellar bands (DIBs) and atomic lines are observed as interstellar absorptions in GALAH and other massive spectroscopic stellar surveys. By observing a given DIB toward many stars which are nearly in the same direction, but at different distances, one can reconstruct absorption sites along the line of sight. ...

... They are concerned with Attitude Control System of the spacecraft, satellite visibility from tracking stations, limits on the satellite autonomous operations during the orbit, and needs for auxiliary operations with the spacecraft. ... Among the operational constraints the most important one is the number of programmed slews per orbit, which determines the maximum number of radio sources to be observed during one orbit. ... System temperature (K) . ... Progress of the RadioAstron Project in Pictures...

This section of AMPLE provides a means for identification of minor planets. ... Due to special organization of the package, AMPLE permits the identification to be reliable fulfilled THROUGHOUT the TITLE YEAR. ... In such cases the result of identification depends on where the nearest opposition of inspected planet is situated, within basic interval lasted from November of preceding year to February of subsequent one or without it. ...

... The first task assumes the searching for chemical composition and sizes of particles which give the wavelength dependence of the extinction efficiencies close to the observed dependence of . Figure 7: Wavelength dependence of the extinction efficiency factors for homogeneous spherical particles of different sizes consisting of astronomical silicate and amorphous carbon. The dashed segment shows the approximate wavelength dependence of the mean galactic extinction curve at optical wavelengths. ...

... ON THE ROLE OF LARGE-SCALE PLASMA IRREGULARITIES AT THE FINAL STAGE OF ANOMALOUS ABSOPTION DEVELOPING UNDER HF HEATING OF THE IONOSPHERE . ... Fig. ... With the aid of numerical statistical modeling based on multiple ray tracing it is shown that in presence of large-scale irregularities the reflected signal amplitude mean value is increased significantly. ... Dependence of the mean amplitude of the reflected from the ionosphere signal on the large-scale (10-50 km) electron density irregularity level...

... We publish 16 Doppler imaging temperature maps for the years 1994-2002 of the active RS CVn star II Peg. ... Through Doppler imaging we want to study the spot evolution of the star and in particular compare this with previous results showing a cyclic spot behaviour and persistent active longitudes. ... The derived temperature maps are quite similar to the ones obtained earlier with a different methods, the main differences occurring in the spot latitudes and relative strength of the spot structures....

... The extinction in terrestrial atmosphere. ... A star was observed at different zenith distances during one night at the Engelgardt's Astronomical Observatory in the program of atmospheric extinction study at blue. ... Calculate the air mass for given zenith distances in 1st 54.9 11800 column, and write the result into the 2nd column. ... Spectral observations. ... Calculate the radial velocity Vr of the star on each date, the results of measurements and write calculations into the table. ...

... Observing . ... Home Education Workshops at Adorama Astronomy Workshop: Observing Variable Stars from the City ? February 15, 2015 . ... Beyond New York City . ... Observing Resources for Amateur Astronomers - Part 1: Beginning Observers . ... A History of the First Forty Years of the Amateur Astronomers Association . ... Presented by€а Adorama €аFor the Amateur Astronomers Association of New York . ... 2016 Amateur Astronomers Association of New York Designed by Press Customizr Powered by . ...

The Solar spots - are the dark formations on the Sun's disk. ... The greatest observed spot is 100 thousand kilomiters. The spots are the places of the magnetic fields' getting out to the solar atmosphere. ... That's why they look so dark . ... The Solar convection zone is the layer with the thickness of 150 - 200 thousand kilomiters, situated under the photosphere; the substance of this layer being in convectional movement transformes the energy from inside the Sun's to its surface. ...

... Hale-Bopp and the Plateau de Bure Interferometer . ... Comet Hale-Bopp is being observed by many different telescopes. ... These telescopes are being used to detect the presence of different molecules in the coma and tail of Comet Hale-Bopp. ... Comet Hale-Bopp is spinning. ... As Comet Hale-Bopp spins, parts of the comet's surface shoot away in jets. ... Arecibo: The Largest Telescope . ... Europa's Ice Rafts . ... The surface of Jupiter's moon Europa has shifted. ... Oceans Under Jupiter's Europa?...

... US state, Canadian province, or country . ... Supernova showered Earth with radioactive debris . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... space flight . ... space physics . ... Space station provides insight into flame behavior . ... We hope to gain a better knowledge of droplet burning, improved spacecraft fire safety, and ideas for more efficient utilization of liquid fuels on Earth," said Forman Williams from the University of California, San Diego. ...

ATMoB "Double Star Award " Guidelines Purpose: To promote observing among the membership of the Amateur Telescope Makers of Boston ­ in particular, double, triple, and multiple stars. Introduction: Double, triple, and multiple stars are the "Rodney Dangerfields" of the night sky. ... W hile they can be observed under a variety of sky conditions, double stars ­ especially close ones ­ are best viewed on nights when the seeing is steady. ... The direction from a star to Polaris is north. ...

Precision Telescope Control System PTCS Project Note 51.1 A Preliminary Analysis of the Correlation Scales of Wavefront Errors of the GBT Using the Moon Bojan Nikolic, Dana S. Balser & Richard M. Prestage 27 June 2006 GBT Archive: PR063 File: PROJECTS Keys: PTCS, OOF Abstract Observations of the GBT error beam are performed using the Moon to explore the spatial scales in the aperture plane over which the dominant wavefront errors are correlated. ... The expected observed scan is shown in Figure 7. ...

Astronomy Discussion Forums . ... What I See . ... Follow Ups | Post Message | ... I have observed the Double Cluster, the BeeHive cluster and other open and various Globular Clusters. My main problem with my 114mm reflector is in its inabliity to bring deep sky objects. ... www.astronomy.net . About Astronomy Net | Advertise on Astronomy Net | ... Forum posts are Copyright their authors as specified in the heading above the post. "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET" . ...

Statistics of sunspot activity . The sunspot indices . ... Visual indices of solar activity . ... n - number of spot groups . A - Waldmeier class of unipolar spot groups without penumbra . B - class of bipolar spot groups without penumbra . C - class of bipolar spot groups with one penumbra pole . D - class of small bipolar spot groups with two penumbra poles . E - class of middle bipolar spot groups with two penumbra poles . ... H - class of unipolar penumbrated spot groups . ...