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Webinar | Recognizing AAVSO’s All Stars

Join us as we celebrate the collective achievements of our community.

https://us02web.zoom.us/webinar/register/6017345582722/WN_RlCkYTyIQi-NKecusrjdOQ

Donate to the AAVSO!

Your support will provide opportunities that will influence generations of observers.

https://www.aavso.org/annual-campaigns/2025-annual-campaign?utm_source=slider&utm_medium=web&utm_campaign=ac25&utm_content=hps241112

RW Cephei, King of Kings

The physical processes behind a hypergiant’s “great dimming” may have been unlocked by high-resolution imagery and a century’s worth of AAVSO observations

https://www.aavso.org/blog/rw-cephei

Discover the AAVSO

An international community

Welcome to the conversation.

We are excited to announce a transition to a new forum system. The new system is modern, faster, and easier-to-use.

https://forums.aavso.org/

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The mission of the AAVSO is to enable anyone, anywhere to participate in scientific discovery through variable star astronomy.

Resources

(VSX) Variable Star Index

jaavso

The Journal of the AAVSO

Data

Submit and Access Data

Telescope

Tools and Observer Resources

Observing Sections

Observing Sections

/observing-sections

Education

Education

CHOICE Courses, Manuals, Videos

AAVSO In the Press

AAVSO In the Press

Membership and Support

The AAVSO is an equal opportunity and discrimination / harassment free environment.
Please read our policies HERE

AAVSO at a Glance

Variable Star Observations in Database:

6 6 , 0 6 3 , 4 4 3 and Counting ...

Last Observation Received:

40 sec ago by SPAO - Paolo Siliprandi (IT)

U Del Dec 30.7 6.7Vis.

Plot U Del light curve

Solar Section Looks Back to the Future

Dec 23

Winter 2024 Visual Observing Challenge

Dec 19

JAAVSO Volume 52 Number 2, 2024 is published

Dec 15

RW Cephei, a King of Kings

Dec 11

Board Election Results

Nov 19

Our Stellar Partners

orange circle with with snake next to the words "The Astropy Project"

$Diffraction Limited logo of a swirled circle with text: Diffraction: Astronomy + Scientific Imaging SolutionsIm$

Black outline of an intricately dressed being with accentuated features

Text reads "Sky & Telescope" with the ampersand in a circle.