... Tonight's Sky . ... The Magazine . ... Observing . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Astronomy for Kids . ... Observing springtime deep-sky objects with a large telescope . ... Bright planets meet at dusk . ... Astronomy magazine subscribers can read the full article for free. ... Get instant access to subscriber content on Astronomy.com! ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter....

... The Pleiades star cluster, also known as the Seven Sisters and Messier 45, is a conspicuous object in the night sky with a prominent place in ancient mythology . ... The stars in the Pleiades are thought to have formed together around 100 million years ago, making them 1/50th the age of our sun, and they lie some 130 parsecs (425 light years ) away. ... Data for these stars are listed in a table below. ... Yes . ... WEBDA Pleiades cluster data . ... M45: The Pleiades Star Cluster (2007 November 18) ...

Download Izmccd (~2.7 MB). ... a) a choice of the best mode of measurements of stars and objects ("Properties/Measurement"), . b) a choice of reference stars. ... 1) necessity of presence on an image of a plenty of stars (we recommend to apply this mode, if on the frame of reference stars is more 100) . ... Sx and Sy depend from residuals at all reference stars (reference stars are marked by blue color). ... These residuals are the image of the star a minus function of a profile for each pixel. ...

... The user database is traditionally contained in the /etc/passwd љ file. Some systems use shadow passwords , and have moved the passwords to /etc/shadow љ . ... However, installing shadow passwords later onto a system that did not support them can be difficult. ... The crack љ program can be used to crack passwords; any password it can find is by definition not a good one. ... The user group database is kept in /etc/group љ ; for systems with shadow passwords, there can be a /etc/shadow.group љ . ...

SAI VO . ... Web Services . Catalog Access Services . ... SAI Web Services . ... This service aims to automatically match stars in FITS image provided with catalogue and add the correct WCS keywords to its FITS header. ... Service Web Interface . ... The service is available here To use it, you has to provide the image as a Base64-encoded string, along with the rough information on image field of view size and center (the latter may be deduced from FITS header keywords like 'RA' and 'DEC'). ...

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... General Catalog of Variable Stars (GCVS database, Version 2012 Feb.) ... The cross-identification tables of the General Catalogue of Variable Stars (GCVS) contain all GCVS (including extragalactic variables from vol.V), NSV (New catalogue of Suspected Variable stars) and Supplement to the NSV stars as well as stars from the name-lists of variable stars nos. 67 - 80; it also makes it possible to find out identifications between the GCVS and the NSV catalogue. ... I-III) names are included. ...

... Satellite data ] . ... SMIS IKI RAN has developed the software package which may be used both by owners of acquisition stations and individual users of satellite information. ... AVHRR instrument data processing. ... This enables the users who are not yet qualified in computer methods of satellite data processing, to get a quick start with the software. ... The basic software package enables a user to solve a wide range of tasks (in our server You can find the data processing samples ). ...

... Structure of Data . ... Catalog . ... The SAI OCL Catalog site provides several VO-enabled modes of operation: . VO-enabled catalog data analysis from a browser . ... Endpoint URL is http://ocl.sai.msu.ru/catalog/conesearch/ . ... VO-enabled catalog analysis from a browser . Presently, this recipe works with Firefox (Windows, MacOS, Linux), Internet Explorer (Windows) and Opera (Windows) browsers with Java plugin 1.6 installed. ... Main TOPCAT window with SAI OCL catalog loaded will appear. ...

You Can Make Stellar Images Brighter . Articles | ... A few months ago I wrote an article titled "You Can’t Make Them Brighter". So why am I now writing that you can make them brighter. ... The image of a focused star is actually a small disk called the Airy disk, named after the 19 th century scientist Sir George Airy. ... For a given aperture, a smaller Airy disk means that the light is focused to a smaller disk and is therefore brighter. ... www.astronomy.net . About Astronomy Net | ...

... Its apparent diameter of 18.0 arc minutes corresponds to a linear extension of about 180 light years; Kenneth Glyn Jones mentions an estimate of even 20 arc minutes from deep photographic plates, corresponding to about 200 light years linear diameter. It appears somewhat smaller in amateur instruments, perhaps about 10 minutes of arc. ... Red: 20x3 minute subs, totaling 1 hour . Green: 20x3 minute subs, totaling 1 hour . ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

Stellarium 0.11.4 . ... SphericalTexturedPolygon . TextureVertex . ... A container for 3D vertex + associated texture coordinates. ... vertex . ... Generated on Wed May 9 2012 11:18:43 for Stellarium by љ 1.7.6.1 ...

... Exposure Time Calculator (ETC) . Survey processing . ... VISTA is a 4-m class wide field survey telescope for the southern hemisphere, equipped with a near infrared camera (1.65 degree diameter field of view at VISTA's nominal pixel size) containing 67 million pixels of mean size 0.34 arcsec and available broad band filters at Z,Y,J,H,K s and a narrow band filter at 1.18 micron. A wide field visible camera, if constructed, could also be used on VISTA. ... Tile . ... ESO VISTA Public Surveys . ...

... 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. ...