They Might Be Hypergiants
AAVSO data has helped unveil the mysteries of Rho Cas and stars like it.
Slider Link
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?”
Slider Link
https://www.aavso.org/blog/future-of-small-telescope-science
Discover the AAVSO
An international community
Slider Link
/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.
Slider Link
https://forums.aavso.org/
Webinar | SIGs in the Spotlight: AAVSOnet, CVs and Spectroscopy
November 15, 2025 on Zoom | Click to Register
Slider Link
https://us02web.zoom.us/webinar/register/6517582032778/WN_dHvJ4-9bRCqJndBDZwBqPg

old logo

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

Resources

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

Pick a Star

Plot a light curve
jaavso
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 5 , 6 4 1 , 5 9 4 and Counting ...

Last Observation Received:

1 min 15 sec ago by SSHA - Sherrill Shaffer (US)

V373 CAS   Nov 8.0514   5.85Vis.

Plot V373 CAS light curve

New User Profiles, Settings, and Search
Oct 22
New Data Usage Guidelines
Oct 7
Voting and Candidates for the 2025 AAVSO Board Election
Sep 18
An Invitation to Board Nominees
Aug 5
JAAVSO Volume 53, Number 1, June 2025, print version now available
Jul 2
News Archives

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

Chroma Technology logo: the word chroma goes through a bright rainbow-colored hoop

Black outline of an intricately dressed being with accentuated features

Unistellar

Boyce Astro Logo

Text reads DC-3 Dreams Observatory Operating Systems

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

NSF

NASA Logo