I’m using the following AAVSO chart for variable star R CrB to check the NELM from my suburban backyard, and on a regular basis.

I can barely see to magnitude 4.2, but not constant and requiring averted vision. When I moved into my current house more than 40 years ago, I could see to magnitude 5.5 at the zenith, but no more. Most of this is due to increased light pollution, as my backyard skies are never really dark anymore. And adding to the problem, my eyes and night vision are not as good as four decades ago either.

For the northern observer, Corona Borealis is almost overhead at certain times, which is perfect for the NELM test.

Roger

I’m using my cellphone to check on T CrB on a regular basis since March 2025. The following was my latest from this morning (April 15th 2026) at 5:00 AM.

This entry was posted on April 15, 2026 at 6:31 pm and is filed under Checking NELM using the constellation Corona Borealis. You can subscribe via RSS 2.0 feed to this post's comments. Responses are currently closed, but you can comment below, or link to this permanent URL from your own site.