Once every 80 years, T Coronae Borealis - also known as the “Blaze Star” - goes nova. When it does this, it brightens from roughly magnitude 9 (likely only visible with telescopes) to magnitude 1 or 2 (roughly as bright as the North Star).

NASA has a great explanation of it, as well as how to find it in the night sky. Astronomy.com also has a great and more detailed article.

While we will certainly hear about it eventually when the nova happens, it is likely only going to be at its best for a day or so. And with algorithmic feeds nowadays, there’s a good chance of missing this fantastic event if that’s how you get your news.

The best source I can find to get the raw scientific data of T CrB’s magnitude is through the community observations contributed to AAVSO (the American Association of Variable Star Observers.)

Here is how to get the observation records for T CrB, currently being observed several hundred times per day:

AAVSO WebObs data for T CrB

AAVSO has described their vetting process, as well as how they will announce to the world in their post, No, it didn’t erupt yet. How AAVSO is vetting T CrB data | aavso.

[Edit 9/29/2026 - AAVSO has released an API to make this much easier. Approach updated below.]

That said, you can use PowerShell to track this data and alert whenever the average of these recent observations increases in brightness past magnitude 9. This doesn’t mean it has for sure gone nova (these are community-submitted) but is definitely worth scrambling for.

1. Register for an account on AAVSO.org.
2. Under “My Account” -> “Settings”, go down to “API Access” and request an API key. They have lots of documentation for this API.
3. Store your API key somewhere safe. Hard-coding it into a script is a bad idea, so use PowerShell’s secret management cmdlets - here is a good resource: PowerShell SecretManagement Module: Securely Manage Credentials and Secrets. In my PowerShell example below, I’ve named the secret ‘aavso’.
4. Run the PowerShell below to get the current average observed brightness.

Measuring Observed Brightness with PowerShell

## Check for T CrB Nova
$secret = Get-Secret -Name aavso
$token = [Runtime.InteropServices.Marshal]::PtrToStringAuto([Runtime.InteropServices.Marshal]::SecureStringToBSTR($secret))
$observations = Invoke-RestMethod "https://apps.aavso.org/v2/api/observations/photometry/?target=000-BBW-825" -Headers @{ "Authorization" = "Token $token" }
$brightness = $observations.Results | Where-Object Uncertainty -lt 0.1 | Measure-Object -Average magnitude | Foreach-Object Average
if(($brightness -gt 1) -and ($brightness -lt 7))
{
    while($true)
    {
        [Console]::Beep(1000, 1000)
        Write-Warning ("T CrB has brightened and is now at magnitude $brightness. " +
            "See https://apps.aavso.org/v2/data/search/photometry/?target=000-BBW-825&page=1.")
    }
}
else {
    "T CrB current magnitude: $brightness"
}

If you use this script, please be nice. I have my automation set to check only every 30 minutes.