CHOICE in Astronomy

What are CHOICE courses?

AAVSO’s Carolyn Hurless Online Institute for Continuing Education (CHOICE) courses improve participants’ astronomy skills in observation, analysis, research, writing, and advocation. Skills developed through each of these informal online courses increase your data collection accuracy, help make your time observing more enjoyable, and enable astronomers and researchers to best utilize AAVSO data.

The courses are available internationally, and are designed for you to work on the material in your own time from day to day. They are primarily conducted in the AAVSO website forum, unless the instructor points to material elsewhere or also conducts live Zoom sessions. Courses in which the instructor uses Zoom are noted in the calendar below. 

Whether you are an AAVSO member or not, you can take as few or as many CHOICE courses as you like. Courses range from introductory to advanced, and cover a variety of topics. Students earn a pass/fail assessment at the end of each course.

Course descriptions and prerequisites 

Available here, or by clicking the name of the course in the below calendar.

Time allotment

Participants devote anywhere from 8–20 hours per week reading, participating discussions, and completing quizzes and exams. Unless otherwise noted, courses are four weeks long. 

To start a course

Once you enroll (see the calendar below), you will receive an email from the Friday prior to the course beginning, with information on how to access the course and participate. 

If you have general CHOICE questions that are not about the course material, or if you do not receive the email by the end of the day (in ET) on the Friday prior to the course starting, please email  

2023 Courses and Registration

Each course is $35.00 for members, or $60.00 for nonmembers. You must be logged in to your AAVSO account at time of purchase. Not a member? Become a member prior to course registration to receive the member price!

Course registrations open on a rolling basis on the first Tuesday of a month. Please click the respective "purchase" button below to register and pay for a course. (If a purchase button is not under the course you want, its registration is not currently open.)

                                                               2023 Schedule

February 6 - March 13 (6 weeks)
Advanced Use of AstroImageJ for Exoplanet Observing

Instructor: Dennis Conti
Features Zoom discussions:
Mondays 7:30 p.m. EST
(Tuesdays 0030 UT)


March 20 - April 30 (6 weeks)
CCD Photometry, Parts 1 & 2

Instructor: Ed Wiley


May 8 - June 4
How to Use VStar

Instructor: Aritra Das

June 5 - July 2
Variable Star Classification and Light Curves

Instructor: Blake Crosby


July 10 - August 6
Developing a Visual Observing Program

Instructor: Mike Poxon


September 4 - September 30
Observing and Counting Sunspots

Instructor: Raffaello Braga

October 2 - November 5 (5 weeks)
Photometry Using VPhot

Instructor: Ken Menzies


13 Novembre - 9 Décembre
Classification des étoiles variables et courbes de lumière

Instructor: Jean-Bruno Desrosiers




Want to become a CHOICE course instructor?

Courses are peer taught—graduates of one course have the opportunity to lead the next iteration of that course. Learning occurs best when done collaboratively, and for many, the best way to learn is to teach. Those who lead a course receive any subsequent CHOICE course free of charge, and an instructor status symbol on their AAVSO profile for each course taught.  

Instructors can always get assistance from AAVSO staff, and use the course syllabi and any other course-related materials. AAVSO staff take care of the technical issues (registration and forum set-up), while the instructors guide the students through the course and perform assessments.

Contact AAVSO at to discuss this opportunity.


About Carolyn Hurless

Carolyn J. Hurless, the most active and prolific female observer in the history of the AAVSO, recorded a total of 78,876 observations for the AAVSO International Database (AID). She also led a remarkable career as an AAVSO observer, councilor, officer, mentor, and advocate.