... Editor's choices for the most educational Astronomy Pictures of the Day about orbiting observatories: . ... The trouble is that Earth-bound telescopes must look through the Earth's atmosphere . ... Telescopes which explore the Universe using light beyond the visible spectrum, such as those onboard the Chandra X-ray Observatory need to be carried above the absorbing atmosphere. ... By orbiting above the Earth's atmosphere, the Hubble Space Telescope, pictured above , can get clearer images. ... Index...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. November 8, 1996 . A Solar Corona Ejection . ... One reason, besides the extreme heat, is that explosions are common there . In the above picture, magnetic fields buckle releasing previously constrained hot material from the upper atmosphere of the Sun . ... CMEs are more common but less intense than solar flares . ... About APOD | ...

Nova 1998 2 in M31 this image of the second Nova in M31 in 1998, was made from 38 exposures of 45 seconds integration time. It was made at September 21, 22h 20m UT. Telescope was a CG11 at f/6.3, no filters were used. The long list of processing steps caused the artefacts at the overexposed center of the galaxy and in many of the brighter stars. During the exposures thin clouds covered the sky but the CCD cuts through them, allowing me to obtain this result. ...

... It is being organized jointly by the Byurakan Astrophysical Observatory (BAO) and the Armenian Astronomical Society (ArAS). ... LIST OF LECTURERS AND LECTURES : Dr. Vladimir AIRAPETIAN (Goddard Space Flight Center, USA): Physics of Winds from Cool Evolved Stars Dr. Don BARRY (Cornell University ... (observation techniques and theory) Dr. Michel DENNEFELD (Institut d'Astrophysique de Paris, France): Introduction to spectroscopic observations Dr. Serguei DODONOV (Special Astrophysical ...

ABSOLUTE PROPER MOTIONS OF 331 OPEN CLUSTERS . ... The proper motions of stars in the fields of 331 open clusters were taken from Four-Million Star Catalog (4M-catalog) of positions and proper motions (Volchkov et al. ... The absolute proper motions for 21 young open clusters have been derived by comparison of precise relative proper motions of individual stars and their corresponding absolute proper motions. ... Sign of proper motions in RA . ... 0.0001 arcsec/yr . ... rms error in RA proper motion . ...

... Отмеченная наградами АстроТоп-а . ... 1) К участию в конкурсе допускаются все российские сайты на тему астрономии и космонавтики, и все русскоязычные сайты за пределами России. ... II) Сайт года . ... Победитель: Астронет - http://www.astronet.ru/ : подано голосов экспертов - 109 (всего - 129) . ... 3-е место разделили: Астрономия и Телескопостроение - http://www.astronomer.ru/ и Лента новостей космонавтики от Железнякова - http://www.cosmoworld.ru/spaceencyclopedia/hotnews/ : подано по 37 голосов; ...

... The distance scales of the objects are matched both by comparing the first derivatives of the angular velocity determined separately from radial velocities and proper motions and by the statistical-parallax method. ... Good agreement between the inferred 0 and our calculations based on space velocities suggests that the Lindblad relation holds throughout the entire sample volume. ... Brandt and Blitz (1993) published the distances and radial velocities for a total of 206 H II-regions. ... Astron. ...