Binocular Variable Star Observing Program


Binocular Variable Star Observing Program Coordinator:
Robert Togni​  


The Astronomical League and American Association of Variable Star Observers (AAVSO) would like to present an entry level binocular program for observing Variable Stars.  It serves as a good way to introduce variable observation, improve observing skills, and supply meaningful Astronomical Data to professionals and amateurs around the world.

The program uses the AAVSO Binocular program 

to supply the list of stars to observe and charts to use them.  Data obtained is submitted to AAVSO for analysis. 

Variable stars are objects whose light is not constant. The observer's goal is to determine the brightness of the star when compared to stars of fixed brightness in or near the same field of view.

Rules and Regulations

To qualify for the Binocular Variable Star Program certificate and award pin, you need to be a member of the Astronomical League, either through an affiliated club or as a Member-at Large and complete these requirements:

  1. Obtain an AAVSO Observer Code from AAVSO.
  2. Make a total of 60 observations of at least 15 different binocular variables with binoculars from the AAVSO Binocular Variable list.
    Upload your observations to the AAVSO website via WebObs
  3. Current Binocular charts must be used from the Variable Star Plotter.
    Data from the Binocular Variable Program cannot be used for the Variable Star Program Award or vice versa.
  4. When you finish, email or mail a list of your variable observations along with your AAVSO observer code to the Binocular Variable Observing Program Coordinator.



Any pair of binoculars can be used.  The wider angle the better because you can get more comparison stars into the field. 7 x 50 are a good choice. 

When printing out charts using the Variable Star Plotter (VSP), start with the chart parameters to the right of the list of Binocular Program Stars.

These are recommended starting values that can be modified to fit your observing style. If you are observing with binoculars from the northern hemisphere select North up and East left to get the proper orientation on printed charts. Observers in the southern hemisphere will need to use other orientations.

You may need a good star atlas to find the general vicinity of your Binocular Variable.  Preparaton is very important. Locate your variables in your star atlas or other aid BEFORE you go outside. AAVSO has some consteallation charts that may be helpful, see:

In the field you will want a red light to review your charts and keep your eyes dark adapted.   Attached is a log sheet for keeping up with your observations or make up your own method. 

Practice memorizing star patterns to avoid going back and forth to your charts.  The more observations you do, the better you’ll get at it.  Pretty soon you’ll be out-observing your old friends and writing down data in a few minutes just using charts for comparison star values.

Note the recommended minimum time between observing variables as described on the AAVSO website:

After completing your Astronomical League Binocular Variable Star Observing Program, check out the AAVSO Variable Star Observing Program and Carbon Star Observing Program.  You may want to continue submitting your observations to the AAVSO.  Make this an exciting and rewarding part of your permanent observing routine.  Consider joining the AAVSO.



VSOP Log Sheet (PDF)


VSOP Log Sheet (Excel)

Variable Star Binocular Pin


Binocular Variable Star Observing Program Coordinator:
Robert Togni​


Citizen Science

If you enjoyed this Observing Program, and look forward to doing more observations to submit to the national or international database, then we invite you to participate in the Astronomical League's Citizen Science Program.  This is an extension of this Observing Program and only requires you to do what you have been doing; observing and submitting those observations.  For more information about this opportunity, please go to the website:  Citizen Science Program.