The Astronomical Almanac Online -- Welcome

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head><script type="text/javascript" src="/_static/js/bundle-playback.js?v=HxkREWBo" charset="utf-8"></script> <script type="text/javascript" src="/_static/js/wombat.js?v=txqj7nKC" charset="utf-8"></script> <script>window.RufflePlayer=window.RufflePlayer||{};window.RufflePlayer.config={"autoplay":"on","unmuteOverlay":"hidden"};</script> <script type="text/javascript" src="/_static/js/ruffle/ruffle.js"></script> <script type="text/javascript"> __wm.init("https://web.archive.org/web"); __wm.wombat("http://asa.hmnao.com/","20101224230506","https://web.archive.org/","web","/_static/", "1293231906"); </script> <link rel="stylesheet" type="text/css" href="/_static/css/banner-styles.css?v=S1zqJCYt" /> <link rel="stylesheet" type="text/css" href="/_static/css/iconochive.css?v=3PDvdIFv" />  <meta http-equiv="content-type" content="text/html; charset=UTF-8"/> <meta name="description" content=""/> <meta name="ROBOTS" content="NOARCHIVE,NOSNIPPET"/> <meta name="keywords" content=""/> <meta name="owner" content=" U.S. Nautical Almanac Office H.M. Nautical Almanac Office"/>  <base href="https://web.archive.org/web/20101224230506/http://asa.hmnao.com/AsA/"/> <link rel="icon" href="/web/20101224230506im_/http://asa.hmnao.com/AsA/favicon.ico" type="image/x-icon"/> <link rel="shortcut icon" href="/web/20101224230506im_/http://asa.hmnao.com/AsA/favicon.ico" type="image/x-icon"/> <link rel="alternate" href="https://web.archive.org/web/20101224230506/http://asa.usno.navy.mil/updates.rss" type="application/rss+xml"/> <link rel="stylesheet" type="text/css" href="/web/20101224230506cs_/http://asa.hmnao.com/AsA/yui/build/reset-fonts-grids/reset-fonts-grids.css" media="all"/> <link rel="stylesheet" type="text/css" href="/web/20101224230506cs_/http://asa.hmnao.com/AsA/yui/build/container/assets/container.css" media="all"/> <link rel="stylesheet" type="text/css" href="/web/20101224230506cs_/http://asa.hmnao.com/AsA/yui/build/menu/assets/menu.css" media="all"/> <link rel="stylesheet" type="text/css" href="/web/20101224230506cs_/http://asa.hmnao.com/AsA/yui/build/calendar/assets/skins/sam/calendar.css" media="all"/> <link rel="stylesheet" type="text/css" href="/web/20101224230506cs_/http://asa.hmnao.com/AsA/asao_screen.css" media="screen"/>  <title>The Astronomical Almanac Online -- Welcome</title> </head> <body> <div id="doc" class="yui-t7"> <div id="hd"> <div id="header"> <a id="ukho" href="https://web.archive.org/web/20101224230506/http://www.hmnao.com/" rel="external"></a> <a id="usno" href="https://web.archive.org/web/20101224230506/http://www.usno.navy.mil/" rel="external"></a> <div id="taao"> <div id="taa">The Astronomical Almanac</div> <div id="o"> <span id="o1"> <span id="o2">Online!</span> <span id="o3">Online!</span> <span id="o4">Online!</span> Online! </span> </div> </div> </div> <div id="asao-menu" class="yuimenubar yuimenubarnav"> <div id="asao-menubar-bd" class="bd" style="visibility: hidden"> <ul id="asao-menubar-list" class="first-of-type"> <li class="yuimenubaritem first-of-type"><a class="yuimenubaritemlabel" href="index.html">Contents</a> <div id="contents-menu" class="yuimenu"> <div class="bd"> <ul> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="index.html">Home</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Intro/Introduction.html">Introduction</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="SecA/Section_A.html">Phenomena (incl. eclipses)</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="SecB/Section_B.html">Time-Scales and Coordinate Systems</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="SecC/Section_C.html">The Sun</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="SecD/Section_D.html">The Moon</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="SecE/Section_E.html">The Planets and Pluto</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="SecF/Section_F.html">Satellites of the Planets and Pluto</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="SecG/Section_G.html">Minor Planets and Comets</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="SecH/Section_H.html">Stars and Stellar Systems</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="SecJ/Observatories.html">Observatory Search</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="SecK/Section_K.html">Tables and Data</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="SecL/Section_L.html">Notes and References</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="SecM/Section_M.html">Glossary</a></li> </ul> </div> </div> </li> <li class="yuimenubaritem"><a class="yuimenubaritemlabel" href="Errata/Errata.html">Errata</a> <div id="errata-menu" class="yuimenu"> <div class="bd"> <ul> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Errata/Errata_2011.html">Errata 2011</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Errata/Errata_2010.html">Errata 2010</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Errata/Errata_2009.html">Errata 2009</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Errata/Errata_2008.html">Errata 2008</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Errata/Errata_2007.html">Errata 2007</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Errata/Errata_2006.html">Errata 2006</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Errata/Errata_2005.html">Errata 2005</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Errata/Errata_2004.html">Errata 2004</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Errata/Errata_2003.html">Errata 2003</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Errata/Errata_2002.html">Errata 2002</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Errata/Errata_2001.html">Errata 2001</a></li> </ul> </div> </div> </li> <li class="yuimenubaritem"><a class="yuimenubaritemlabel" href="SecK/Constants.html">Constants</a></li> <li class="yuimenubaritem"><a class="yuimenubaritemlabel" href="SecM/Section_M.html">Glossary</a></li> <li id="utilities-menuitem" class="yuimenubaritem" style="visibility: hidden"><span class="yuimenubaritemlabel">Utilities</span> <div id="utilities-menu" class="yuimenu"> <div class="bd"> <ul> <li class="yuimenuitem"><span id="geo-coords-menu-link" class="yuimenuitemlabel fake-link">Planetary Geocentric Coordinates</span></li> </ul> </div> </div> </li> <li class="yuimenubaritem"><a class="yuimenubaritemlabel" href="Intro/Additional_Info.html">Additional Info</a> <div id="additional-menu" class="yuimenu"> <div class="bd"> <ul> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Intro/Links.html">Noted Links</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Intro/Contributors/Contributors.html">Contributors</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Intro/Order.html">Ordering</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Legal/Legal.html">Legal</a></li> <li class="yuimenuitem"><a class="yuimenuitemlabel" href="Intro/Contact.html">Contact Us</a></li> </ul> </div> </div> </li> </ul> </div> </div> </div> <div id="bd"> <div id="utilities"> <div id="geo-coords-utility" class="asao-panel" style="visibility: hidden"> <div id="geo-coords-header" class="hd">Geocentric Planetary Coordinates</div> <div id="geo-coords-body" class="bd"> <div id="geo-coords-output"></div> <div class="container-hrule"></div> <div id="geo-coords-date"> <a href="SecM/Glossary.html#geocentric-coordinates">Geocentric coordinates</a> for 0h <a href="SecM/Glossary.html#tt">TT</a> on<br/> <span id="verbose-geo-date" class="verbose-date"></span>  <button id="geo-showcal" type="button" title="Show Calendar"> <img src="/web/20101224230506im_/http://asa.hmnao.com/AsA/yui/examples/calendar/assets/calbtn.gif" width="18" height="18" alt="Calendar"/> </button> </div> </div> <div id="geo-calendar-dialog" class="asao-dialog yui-skin-sam" style="visibility: hidden"> <div class="hd">Date for Geocentric Coords.</div> <div class="bd"> <div id="geo-calendar"></div> </div> </div> </div> </div> <div class="yui-b"> <h1 id="title">Welcome</h1> <div id="description"> <p> <em>The Astronomical Almanac</em> is a joint publication of the U. S. Nautical Almanac Office, United States Naval Observatory (USNO), in the United States and Her Majesty's Nautical Almanac Office (HMNAO), United Kingdom Hydrographic Office (UKHO), in the United Kingdom. The printed version contains precise ephemerides of the Sun, Moon, planets, and satellites, data for eclipses and other astronomical phenomena for a given year, and serves as a world-wide standard for such information. The online version extends the printed version by providing data best presented in machine-readable form. </p> <br/> <p> These pages are available at <a href="https://web.archive.org/web/20101224230506/http://asa.usno.navy.mil/">USNO</a> and <a href="https://web.archive.org/web/20101224230506/http://asa.hmnao.com/">HMNAO</a>. </p> </div> </div> <div id="yui-main"> <span id="spacer"> </span> <div id="main" class="yui-g"> <div id="contents" class="yui-u first"> <ul id="toc"> <li class="section"> <span><a class="secLink" id="introLink" href="Intro/Introduction.html">Introduction</a></span> <div class="secContent" id="introContent"></div> </li> <li class="section"> <span><a class="secLink" id="errataLink" href="Errata/Errata.html">Errata in printed editions</a></span> <div class="secContent" id="errataContent"></div> </li> <li class="section"> <span><a class="secLink" id="aLink" href="SecA/Section_A.html">Section A: Phenomena (incl. eclipses)</a></span> <div class="secContent" id="aContent"></div> </li> <li class="section"> <span><a class="secLink" id="bLink" href="SecB/Section_B.html">Section B: Time-Scales and Coordinate Systems</a></span> <div class="secContent" id="bContent"></div> </li> <li class="section"> <span><a class="secLink" id="cLink" href="SecC/Section_C.html">Section C: The Sun</a></span> <div class="secContent" id="cContent"></div> </li> <li class="section"> <span><a class="secLink" id="dLink" href="SecD/Section_D.html">Section D: The Moon</a></span> <div class="secContent" id="dContent"></div> </li> <li class="section"> <span><a class="secLink" id="eLink" href="SecE/Section_E.html">Section E: The Planets and Pluto</a></span> <div class="secContent" id="eContent"></div> </li> <li class="section"> <span><a class="secLink" id="fLink" href="SecF/Section_F.html">Section F: Satellites of the Planets and Pluto</a></span> <div class="secContent" id="fContent"></div> </li> <li class="section"> <span><a class="secLink" id="gLink" href="SecG/Section_G.html">Section G: Minor Planets and Comets</a></span> <div class="secContent" id="gContent"></div> </li> <li class="section"> <span><a class="secLink" id="hLink" href="SecH/Section_H.html">Section H: Stars and Stellar Systems</a></span> <div class="secContent" id="hContent"></div> </li> <li class="section"> <span><a class="secLink" id="jLink" href="SecJ/Observatories.html">Section J: Observatory Search</a></span> <div class="secContent" id="jContent"></div> </li> <li class="section"> <span><a class="secLink" id="kLink" href="SecK/Section_K.html">Section K: Tables and Data</a></span> <div class="secContent" id="kContent"></div> </li> <li class="section"> <span><a class="secLink" id="lLink" href="SecL/Section_L.html">Section L: Notes and References</a></span> <div class="secContent" id="lContent"></div> </li> <li class="section"> <span><a class="secLink" id="mLink" href="SecM/Section_M.html">Section M: Glossary</a></span> <div class="secContent" id="mContent"></div> </li> <li class="section"> <span>Section N: Index</span> <div class="secContent" id="nContent"></div> </li> <li class="section"> <span><a class="secLink" id="additionalLink" href="Intro/Additional_Info.html">Additional Information</a></span> <div class="secContent" id="additionalContent"></div> </li> </ul> </div> <div id="diary" class="yui-g"> </div> </div> </div> </div> <div id="ft"> <span id="release">The Astronomical Almanac Online! 2011</span>  </div> </div> <script type="text/javascript" src="/web/20101224230506js_/http://asa.hmnao.com/AsA/yui/build/yahoo-dom-event/yahoo-dom-event.js"></script> <script type="text/javascript" src="/web/20101224230506js_/http://asa.hmnao.com/AsA/js/sitecode-min.js"></script> <script type="text/javascript" src="/web/20101224230506js_/http://asa.hmnao.com/AsA/js/asao_yui-min-concat.js"></script>  <script type="text/javascript" src="/web/20101224230506js_/http://asa.hmnao.com/AsA/js/header-min.js"></script>  <script type="text/javascript" src="/web/20101224230506js_/http://asa.hmnao.com/AsA/js/utilities-min.js"></script> <script type="text/javascript" src="/web/20101224230506js_/http://asa.hmnao.com/AsA/js/diary-min.js"></script> </body> </html>

CINXE.COM

The Astronomical Almanac Online -- Welcome