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General Public

So you are interested in variable stars...

Variable stars are stars that change measurably in brightness. When you see stars in the night sky, they may seem to be the same night after night. But if you watch them closely, and over time, you'll see they may change quite a bit. In fact, at some level almost all stars are "variable". Even our Sun is a variable star!

Mentor Program

(If you are interested in volunteering as a mentor, please click here.)

Why should I have a mentor?

PEPObs user guide

PEPObs was developed from legacy code used to reduce photoelectric photometry submitted to the AAVSO PEP program.  We have retained most of the original fields for backwards compatibility with old PEP reports.  What follows is a guide to  fields in the online form with formatting instructions.  In the examples, the quotes ("") should not be included.

AAVSO 49 Bay State Rd. Cambridge, MA 02138 617-354-0484