How sunspot groups are numbered, labeled on images of solar disc ?

Announcement: New Forums

We are excited to announce the launch of our new forums! You can access it forums.aavso.org. For questions, please see our blog post. The forums at aavso.org/forum have become read-only.

We are excited to announce the launch of our new applications! We're opening up early access to our new applications for searching, downloading, and submitting photometric observations. You can now access these applications through these links:

• •  Global Data Search (new) – Search across all of AAVSO’s databases
• •  Search and Download Photometric Observations – Search and export results in CSV, JSON, or XLSX
• •  Submit Photometric Observations – Review your observations on a light curve with historical data

We ask for your feedback in order to help us improve these applications. Please send feedback for the applications above to feedback@aavso.org. Note: please avoid duplicating submissions across the two submit applications.