... Tonight's Sky . ... The Magazine . ... Observing . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Astronomy for Kids . ... Imaging Basics . ... The right number of images . ... Get instant access to subscriber content on Astronomy.com! ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ... Astronomy Magazine . ...

... Posts tagged ?PDF? ... Probability density functions are another way of summarizing the consequences of assuming a Gaussian error distribution when the true distribution is Poisson. ... The figure below ( AAS 472.09 ) compares the pdfs for the Poisson intensity (red curves) and the Gaussian equivalent (black curves) for two cases: when the number of counts in the source region is 50 (top) and 8 (bottom) respectively. ... Tags: background , gaussian , PDF , Poisson . ... ArXiv] 4th week, Nov. 2007? ...

Astronomy Picture of the Day . ... 31.05.2015 . ... Credit Copyright: High-Z Supernova Search Team , HST , NASA Explanation: Long ago, far away, a star exploded. Supernova 1994D , visible as the bright spot on the lower left, occurred in the outskirts of disk galaxy NGC 4526 . Supernova 1994D was not of interest for how different it was, but rather for how similar it was to other supernovae . ... Publications with keywords: supernova - cosmology . ... A Supernova through Galaxy Dust . ...

FORMAT ------------------------------------------------------- Format for Russian radar ranging of planets (1962-1995) columns format content 4 i1 planet: 1-Mercury , 2-Venus, 4-Mars 7-8 i2 number of the transmitting station 11-12 i2 number of the receiving station 15-27 f13.3 date and time of signal emission: 15-18 year 19-20 number of the month 21-22 the day of the ...

... These are just the bare bones--just three basic ideas and rules for handling relations ("equations") involving unknown quantities whose values you are trying to find. In most calculations you try to find a number . ... To get a solution, one must replace the given equation (or equations) with others, containing the same information but cleaner in appearance. ... If you have an equation and modify both its sides in exactly the same way, what you get is also a valid equation. ...

Astro Space Center RadioAstron Newsletter Number 17 October 26, 2012 ====================== The process to select projects for the open RadioAstron observing time within the AO-1 period (July 2013 - June 2014) has started From the middle of 2013 RadioAstron will move to the open sky phase of its science operations. Any scientist in the world can apply for the RadioAstron observing time. ... An initial Letter of Intent (LoI) should have been directed to the Mission by 17 October 2012. ...

Winer Observatory P.O. Box 797, Sonoita, Arizona 85637-0797, USA . ... Site . Weather . Roof Status . ... Average Max. ... 0.0 . ... In 2004, the roof was operated manually, while in 2005 through 2007, it was operated automatically by computer, but was not closed by weather sensors. ... The "Closed" column includes those nights outside the Monsoon season when the Observatory was closed due to weather (the usual cause), equipment failures, or vacation by the Winer staff in 2004 through 2006. ...

... 28 April 2010 FTT kick-off meeting 5 Where are we today? Use results from this to secure funds for expansion post 2012 Majority of funds from NMT ­ possibility of some STFC support 28 April 2010 FTT kick-off meeting 6 The FTT /NAS system Ensures that the light beam collected by a telescope is sent down the beam relay pipes in the right direction The FTT /NA system monitors the light The active secondary mirror redirects it 28 April 2010 FTT kick-off ...

... Sun's ecliptical positions. Explanations. Each row contains at 0h of Time Dynamical Terrestrial: month, day , day of the week, julian day number at beginning of day (only last three digits is given, add head of column to form correct number ), longitude in system of mean equinox of date (degrees, minutes, seconds ), two latitudes (the first for mean equinox of date and the second for mean epoch of year; seconds ), radius-vector (astron. units), precession in ...

... CI ) - Cm (I )) ( = 2 (I) N 2 2 PKS0558-504 simultaneous fitting The Chi-Squared is the most common statistic in use to fit a function f to data {x, y} : = 2 N ( yi - f ( xi )) 2 2 i N = number of data points i2 = variance (related to the measurement error for yi ) y = independet variable x = dependet variable f = assumed relationship between x and y yi = observed mean f(x i ) = predicted mean Statistical concepts relevant to data ... 2 * < 1 { (I) OVERESTIMATED} BAD FITTING!! ...

Once students get the hang of it, they can find and measure the brightness of Delta Cephei in a few minutes. ... of Delta Cephei . ... Oct. ... The following table lists the measurements of Delta Cephei made by one amateur astronomer in autumn 1990. ... 4.0 . ... This activity is a simplified version of one that appeared in Hands-On Astrophysics, a series of activities prepared by the American Association of Variable Star Observers with support from the National Science Foundation. << previous page | ...

... 2006 March 6 . Unexpected Comet Pojmanski Now Visible . ... Explanation: Have you ever seen a comet? ... Comet Pojmanski , officially designated C/2006 A1 and discovered only in January, now sports a turquoise tail several times longer than the full moon. Comet Pojmanski 's ion tail is due to gas particles expelled by the comet being pushed away from the Sun by the solar wind , the same wind that ionizes gas in the tail causing its blue tint. ... About APOD | ... NASA Official: Jay Norris. ...

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HIGH MASS X-RAY BINARIES AND RECENT STAR FORMATION HISTORY P. Shtykovskiy 1 1,2 and M. Gilfanov 2,1 Space Research Institute of Russian Academy of Sciences, Moscow, Russia 2 Max-Planck-Institut fur Astrophysik, Garching b. Munchen, Germany Ё Ё ABSTRACT Based on the XMM-Newton observations of Magellanic Clouds we consider the dependence of population of high mass X-ray binaries on the recent star formation history in the host galaxy. ... HMXBS AND RECENT STAR FORMATION IN MAGELLANIC CLOUDS 4.1. ...

... ASRAS HOME . Radio Astronomy . ... About ASRAS . ... Our Observing Site . ... 2015 Mees Tour Guides . ... We're offering Regular Tours (a presentation on astronomy geared to a general audience, followed by a tour of the observatory and (hopefully!) observing of several objects, which may include the Moon, planets, nebulae, star clusters and perhaps galaxies), and Kids' Tours (a more interactive presentation specially aimed at youngsters plus the observatory tour and observing) as in prior years. ...

... Home Gallery Astrophotography Urban Lunar Eclipses . ... Beyond New York City . ... Observing Resources for Amateur Astronomers - Part 1: Beginning Observers . ... A History of the First Forty Years of the Amateur Astronomers Association . ... Several lunar eclipses have been visible from the New York area as these photographs from AAA members show. ... Penumbral lunar eclipse, New York City . ... 2016 Amateur Astronomers Association of New York Designed by Press Customizr Powered by . ...

This module provides for the generation of Expires HTTP headers according to user-specified criteria. ... This module controls the setting of the Expires HTTP header in server responses. The expiration date can set to be relative to either the time the source file was last modified, or to the time of the client access. ... ExpiresByType . ExpiresDefault . The ExpiresDefault and ExpiresByType directives can also be defined in a more readable syntax of the form: . ... Module: mod_expires . ...

... a journal of his thoughts and experiences, some two million words in . ... The boy's sled gets put away in the barn or shed, and there it lies . dormant all summer, like a woodchuck in winter. ... sees a sled, nor a sled a woodchuck, unless it were a prematurely risen . ... Journal, 25 March 1860 . ... Please join us for a pre-meeting dinner discussion at Changsho, 1712 Mass Ave, Cambridge, MA at 6:00pm before the meeting. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

. | Front page | . | << - Number Counts | . Robert J. Smith, ">rsmith@mso.anu.edu.au Last modified: Fri Sep 24 11:39:02 EST 1999 .

... Exposure Time Calculator (ETC) . ... ESO - Public Surveys . ... the recommended values to use for DIT, . ... Detector on-chip integration (DIT): seconds. to your chosen value - a separate page gives recommended values to use for DIT - for modes 1 and 2 below you may wish to start with the maximum recommended values as these will minimize the effect of read noise (a total object exposure of Y secs with DIT=X secs will produce Y/X lots of read noise) and give you a lower limit on the time needed. ...