observing aids

AAVSO-produced JD Calendars give the last four digits of the Julian Day for each day of every month for a year. The months January-June are on one page while July–December are on the second page. For the complete JD, add 2,460,000 (or 2,450,000 if using a calendar dating from before February 23, 2023) to the four-digit value given in the calendar for the Astronomical Day of your observation.

Click on a year in the left column to download a 2-page .pdf version of the calendar for that year. The calendar for 2026 is shown below. Click on the image below to get a bigger version. 

What do I do when I discover a new variable star?

(Jump to Reporting Possible Nova Discoveries)

Complete Manual - 2013 edition
Handbuch zur Beobachtung von veränderlichen Sternen (6.1 MB)

Predicted Dates of Maxima and Minima of 381 Long Period Variables for 2016

A Greek translation of The AAVSO DSLR Observing Manual is now available for download.

Many thanks to Mr. Stelios Kleidis for his tremendous volunteer effort in creating this excellent translation.