The 2025 Observer's Handbook

The Observer's Handbook is a 352-page guide published annually since 1907 by The Royal Astronomical Society of Canada. With the expertise of more than 75 contributors, the Observer's Handbook is regarded as the standard North American reference for data on the sky. The USA Edition continues to be a popular addition, using American cities for examples of sunrise and moonrise, solar ephemeris, etc. Star Parties and Planetaria are for US locations, and we have partnered with the Astronomical League for a section written by their President Carroll Iorg.

The various sections in the Observer's Handbook are of two kinds:

Upcoming Astronomical Events

Events that occur during the current year, such as:

• times of sunrise and sunset and moonrise and moonset (for latitudes 20º to 60º N);
• Moon phases and other lunar phenomena;
• conjunctions, elongations, etc. of the planets;
• eclipses, transits, occultations by the Moon and by planetary bodies;
• location of the planets, dwarf, and minor planets and returns of periodic comets;
• times of meteor showers;
• the orbital positions of the brighter satellites of both Jupiter and Saturn; and
• predictions of the cycles of many variable stars.

The Sky Month By Month section gives an extensive listing of events throughout the year.

Astronomical Reference Information

Astronomical data and other static information (although revisions are made annually to ensure
that the information is the best available) includes:

• a section on observing artificial satellites;
• an annual feature starfield—2024 is Orion;
• advice on using the Observer's Handbook for teaching astronomy;
• orbital and physical data on the planets and their satellites;
• astronomical and physical constants;
• some optical properties of telescopes and binoculars;
• a section on the electromagnetic spectrum;
• information on filters for astronomical observing;
• light pollution and sky transparency;
• a description of the various systems of specifying time;
• information on the Sun including sunspots and aurorae;
• sections on solar and lunar observing;
• sections on astronomical sketching and digital photography;
• essay on deep-sky objects;
• section and observing list "Wide-Field Wonders"
• a list of meteorite craters in North and Central America;
• sections on fireballs and meteorites;
• information on the Gegenschein and zodiacal light;
• a section on sky phenomena;
• 40 pages of authoritative tables dealing with stars, star clusters, nebulae, and galaxies; and
• maps of the Moon and of the entire stellar sky

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