... Bad Astronomy . ... I think I will break from my usual format of Bad Astronomy/ Good Astronomy by saying that the way we define seasons currently is not strictly bad, but I feel (in my opinion!) that it could be better. The definition of when the seasons begin is at the moment of solstice or equinox; that is, winter (in the north) starts on December 22 nd and summer starts on June 22 nd . ... Now imagine breaking up the Sun's 46 degree up-and-down yearly swing into 1 day intervals. ...

... CEPHEID VARIABLE STARS: A Cepheid variable or Cepheid is a member of a particular class of very luminous, massive variable stars with pulsation periods of 1-70 days. ... The relationship is calibrated using data collected from Cepheids whose distances are determined by other means. ... Browse through the 68 CCD fits images he sent you, using ds9 and locate the Cepheid variable. ... Image credits: ESA - "http://sci.esa.int/science-e-media/img/20/cepheid-variables.jpg" . ...

The Astronomy Shop . ... AstroGuide | ... Meteors | ... Shop | ... Books | ... Want an enlightening textbook on astronomy that you can read with joy?Here you'll find detailed explanations and diagrams for all aspects ofpositional astronomy. ... Web . www.astronomy.net . About Astronomy Net | Advertise on Astronomy Net | ... Unless otherwise specified, web site content Copyright 1994-2016 John Huggins All Rights Reserved . dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET" . ...

... Model . ... Karpachev A.T., IZMIRAN, e-mail: karp@izmiran.ru . ... To the Model: . The empirical median model of the shape and position of the MIT (Main Ionospheric Trough) in the Northern and Southern Hemispheres is presented. ... Geomagnetism and aeronomy, v.26, № 1, p.63-68, 1986. ... Karpachev A.T., Afonin V.V. Dependence of the ionospheric trough occurrence probability on the season, local time, longitude, and level of magnetic activity Geomagnetism and aeronomy, v.38, № 3, p.79-91, 1998. ...

ПЕРЕЛ?К ПУБЛ?КАЦ?Й СП?ВРОБ?ТНИК?В ГАО . ... Proc. Journees 2005 "Earth dynamics and reference systems: Five years after of the IAU 2000 Resolutions", Warsaw, 19-21 Sept., 2005/ Ed. by A.Brzezinski et al.- ... Пугач А.Ф. Ковальчук Г.У. Бальмеровский эмиссионный декремент трех звезд с непериодическими ослаблениями блеска. ... Пугач А.Ф. Ковальчук Г.У. Синтетическая кривая блеска R Северной Короны. ... ГАО АН Украины . ... ГАО-93-2Р . ... Ковальчук Г.У. BN Ori: Начало нового периода активности ? ...

... 8, ``Celestial Mechanics'', 2002 Rotation theory of celestial bodies: dynamical relations of the pole motion and nutation Yu. ... Problem By construction Earth rotation theory the studies of the precession--nutation motion and pole motion are considered usually separately. ... The angle Q between the polar axis of inertia and axis of rotation is small (of order 10 \Gamma6 ). ... The perturbation theory of the Earth rotation has been constructed in the elastic Andoyer and angle--action variables. ...

... The areas between the contours were measured automatically. The results of the measurement are represented on fig.1 The graphic shows the distribution of the height levels against their areas. ... USGS, USA Fig.1 The dependence of the distribution of the heights levels versus the area occupied Fig.2 The distribution of the areas of heights levels in the northern and southern hemispheres Fig.3 The distributions of the areas heights levels in eastern and western hemispheres of Mars ...

. Welcome to AstroNet . Sternberg Astronomical Institute . Moscow University . What is the AstroNet , people, facilities and perspectives . SAI Crimean Observatory . SAI Astronomical Databases . Collection of Net references . AstroWeb: Astronomical Internet Resources . Net Search . Today's Weather Map of Russia . Any questions or bug reports regarding this mirror of SAI MSU Home Page should go to M.G.Gavrilov .

... VaST is a software tool for finding variable objects on a series of astronomical images. ... VaST performs object detection and aperture photometry using SExtractor on each image, cross-matches lists of detected stars, performs magnitude calibration with respect to the first (reference) image and constructs a lightcurve for each object. ... VaST FITS image viewer ./pgfv . ... Part I" PZP, vol. ... K. V. Sokolovsky, S. A. Korotkiy; "New Variable Stars Discovered by the NMW Survey" PZP, vol. ...