From 8b8f51fec5961f7fd4c793a85df8866e8b5c12f8 Mon Sep 17 00:00:00 2001
From: Daniel Garcia Briseno <94071409+dgarciabriseno@users.noreply.github.com>
Date: Thu, 14 Dec 2023 08:18:59 -0500
Subject: [PATCH] Update README.md

---
 README.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/README.md b/README.md
index 6537a51f0..82f443e97 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,6 @@
+# Notice:
+The primary branch is now `main`. You are viewing the old `master` branch which is no longer updated.
+
 # Helioviewer
 
 Helioviewer.org is a web application visualization tool for solar physics data based on the JPEG 2000 image compression standard.