AAVSO’s Annual Campaign
Donate Now to Support Variable Star Education.
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https://www.aavso.org/donate-now
They Might Be Hypergiants
AAVSO data has helped unveil the mysteries of Rho Cas and stars like it.
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https://www.aavso.org/blog/they-might-be-hypergiants
A Universe of Opportunity: The Future of Small Telescope Science in the LSST Era
Each time a major sky survey comes online, the inevitable question arises: “Is this the end of amateur astronomy?”
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https://www.aavso.org/blog/future-of-small-telescope-science
Discover the AAVSO
An international community
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/welcome
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.
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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

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(VSX) Variable Star Index
/index.php/vsx

Pick a Star

Plot a light curve
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The Journal of the AAVSO
/index.php/apps/jaavso
Data
Submit and Access Data
/index.php/databases
Telescope
Tools and Observer Resources
/index.php/observers
Observing Sections
Observing Sections
/index.php/observing-sections
Education
Education
CHOICE Courses, Manuals, Videos
/index.php/education
AAVSO In the Press
AAVSO In the Press
/index.php/press
Membership and Support
Membership and Support
/index.php/join-aavso

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:

7 9 , 9 0 7 , 6 5 4 and Counting ...

Last Observation Received:

30 min 54 sec ago by SPP - Phil Sullivan (US)

EU CAS   Jan 1.9507   15.801B

Plot EU CAS light curve

Director’s Report - 2025-Q3/Q4
Jan 5
JAAVSO Volume 53, Number 2, December 2025, print version now available
Dec 17
JAAVSO Volume 53 Number 2, 2025 is published
Dec 15
Director’s Report for 2025-Q2
Dec 2
New User Profiles, Settings, and Search
Oct 22
News Archives

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