... In 1930, Trumpler noticed that linear diameters (LD) of open clusters increase with distance (D) from the Sun. ... Since that time, the interstellar absorption has become one of the best studied factor in astrophysics, and we may hope that current OCL distance scales are free from this LD-D correlation. To verify if this is the case we have chosen several modern OCL distance scales and test them with the same clusters and the same angular diameters that Trumpler had used back in 1930. ...

... Subject and Problems of Stellar Astronomy. ... Plane of Galaxy, Methods of Its Location Determination. ... Stars Distances. ... Other Methods of Stars Distances Determination. ... Tangential Velocities, Their Determination by Self-Motions. ... Determination of Solar Apex and Spatial Velocity by Radial and Spatial Velocities of Stars. ... Features of Orientation and Parameters of Peculiar Stellar Velocities Ellipsoid. ... General and Selective Light Absorption in Galaxy. ... Darc Clouds in Galaxy. ...

... Events . ... The orbit of the Moon is too small to be seen on this scale, but the 2008 December 1st alignment was especially interesting because additionally Venus was occulted by the Moon (this occultation was visible from Europe and NW Africa). Some more photos of the 1 December events received from Jonathan Bingham . ... Venus coming out from behind the Moon; photograph by Jonathan Bingham . ISS; photograph by Jonathan Bingham . ... International Year of Astronomy, Ireland National Node . ...

... 2013: . Evidence for the connection between turbulent gas motions and star formation in dwarf galaxies . ... Moiseev A.V. "Ionized gas rotation curves in nearby dwarf galaxies", Astrophysical Bulletin, 2014, Volume 69, Issue 1 . Moiseev A.V., Tikhonov A.V., Klypin A.A. "What controls the ionized gas turbulent motions in dwarf galaxies", submitted to MNRAS . ... Determination of the mass of a supermassive black hole in AGN Mkn6 based on spectro-polarimetric observations . ... Archive . ...

The orbital period of a satellite increases as its mean distance from Earth grows. The space shuttle in a low altitude circular orbit, just above the atmosphere, completes one circuit in about 90 minutes. ... If you have a suitable calculator, you can easily chek the value of T for R=6.6] A satellite orbiting above the equator at that distance keeps its position above the same spot on the ground; hence this is known as the synchronous orbit, from the Greek syn--same, chronos--time. ...

. Next: Distribution in size of Up: The Interstellar medium Previous: Refractive scintillation . љ . Fresnel diffraction close to thin screen . Fraunhoffer diffraction far from thin screen . Fresnel distance - transition occurs . Jon Bell . Thu Dec 19 15:15:11 GMT 1996

... Materials needed: Ъ At least 1 meter of paper tape per person, such as adding machine paper Ъ Pen or pencil each Just to review, the order of the planets and large objects going out from the Sun and their average distances are: Object Distance in kilometers Distance in AUе Mercury 58 million 0.39 Venus 108 million 0.72 Earth 150 million 1 Mars 228 million 1.52 Asteroid Belt (including Ceres г) 416 million 2.77 Jupiter 778 ... Fold the Sun to the Asteroid Belt mark and crease it. ...