... Over the first 4 years, its X-ray telescopes eROSITA and ART-XC will survey the whole sky with a record sensitivity in the 0.5-10 keV energy band. ... The goal of the second international Spectrum-RG conference is to discuss the different scientific topics addressed by the mission, synergies with surveys at other wavelengths, and requirements to follow-up observations.Contributed talks and poster presentations are invited on the topics related to the SRG science goals. ... Active galactic nuclei . ...

... Liyong Liu (NAOC) . Site testing on seeing conditions of the astronomical observatories over China are briefly reviewed, including Xionglong station of NAOC, Gaomeigu station of Yunnan Observatory, Delingha station of Purple Mountain Observatory. ... PDF [3.0€аMB] October 8, 09:55 10:20 . ... In this paper, we will review the site survey activities in the past years, and present the site-testing results on the Oma site, including cloud cover, seeing, water vapor, transparency and sky brightness. ...

... Image Quality of the VLT . Total Optical Control . First light for the ESO VLT unit telescope 1 occurred during the workshop. ... The image shown (Figure 1 ) here was obtained with the VLT on May 16, 1998, in red light (R band), i.e. while the mirror was still uncoated. ... In this diagram (FIgure 2), the measured image quality of the VLT UT1 astronomical images is plotted versus the ``seeing", as measured by the Seeing Monitor, a small telescope also located on top of the Paranal Mountain. ...

ASTRONOMY IN UKRAINE - 2000 AND BEYOND . ... Kyiv, Ukraine, 5-8 June 2000 . ... The primary objective of the conference is to consider the integration of astronomical research in Ukraine into the international astronomy. ... VLBI for Astronomy and Geodynamics Convenors: Kees van't Klooster (The Netherlands), Leonid M. Litvinenko (Ukraine), Chopo Ma (USA). ... Planetary Astronomy Convenors: Teodor Kostiuk (USA), Robert Nelson (USA), Yuri Shkuratov (Ukraine). ... The "general" registration fee: 100 USD. ...

Photon Scattering: Basic Principle of Photon Scattering . Audio Narration is available . No Scattering: Photon Source and Detector . ... For optical photons, scattering goes as wavelength to the -4 power. In the case of blue photons compared to red photons, this means that blue photons are about 10 times more likely to get scattered than red photons. ... Watch the blue photons scatter away from the detector . ... Interstellar dust make stars appear redder than they really are . ...

Next: A candidate young galaxy? Up: Results and discussion Previous: Current star formation rate . The integrated H I line flux, the characteristic widths of 21 cm line profile W 50 and W 20 (for a Hanning smoothing of 10.6 km s -1 ), and the derived H I mass for HS 0822+3542 are presented in Table 1 . The small H I mass 2.4 of this galaxy is consistent with its low optical luminosity. ... A rough estimation can be made also on the dynamical mass of HS 0822+3542. ...

... One of this year's largest mass ejections from the Sun's atmosphere was recorded last Sunday by TESIS telescopes aboard the CORONAS-PHOTON satellite ( video - wmv 4.3 MB ). ... Over the course of a week, two gigantic solar prominences were simultaneously ejected from the surface of the Sun. ... Earth will not feel the Sun's influence either. ... The TESIS observatory ї TESIS: www.tesis.lebedev.ru . ... One of this year's largest mass ejections from the Sun's atmosphere (movie WMV, 4.3 MB) . ...

Optical Observatories . ... National Optical Astronomy Observatories . ... Adam Mickiewicz University - Astronomical Observatory . ... Astronomical Institute and National Observatory of Athens . ... Jagiellonian University Astronomical Observatory - Scientific research here comprises radio and extragalactic astronomy, solar radio emission, active galactic nuclei, interstellar matter, galaxies, cosmology, variable stars and comets. ... National Radio Astronomy Observatory Home Page . ...

... Observatory . ... The Laboratory of Astrometry . Dept. for Physics of Stars&Galaxies . ... Astronomical Calendar . ... UkrVO . ... The purpose of research: Creating a stellar catalog to study the structure and kinematics of star systems, including open star clusters and stars with large proper motions; the enhancement ICRF / Hipparcos system to stars dawn to 17 m (V); Search of binary systems of brown dwarfs and determination of their parameters; astrometry of minor bodies of the Solar System. ...

... SAI CAS . ... Catalog Access Services . ... This site is about the Virtual Observatory project at the Sternberg Astronomical Institute, Moscow University ( SAI MSU ). We provide a public access to the growing set of astronomical services developed by the SAI RVO development team in accordance with the Virtual Observatory standards. ... We provide access (programmatic and interactive) to the all major and biggest astronomical catalogs (about 4 billions objects total) as well as other web-services. ...