The Christmas Tree Nebula

We're taking a short break.

Author

Adam McMaster
December 27, 2025 • Estimated Reading Time: 2 minutes

Welcome to Three Alpha! We’re taking a short break for Christmas, but we will return in the new year.

Please enjoy this photo from the Spitzer Space Telescope of NGC 2264, the Christmas Tree Nebula. This is an emission nebula, containing many young stars, about 2,300 light years away in the constellation Monoceros.

The Christmas Tree Nebula. Credit: NASA/JPL-Caltech/P.S. Teixeira (Center for Astrophysics)

See you in 2026!

What is Three Alpha? Other than being the name of the newsletter you’re reading now, the name “three alpha” comes from the triple-alpha process, a nuclear chain reaction in stars which turns helium into carbon. Read more here.

Who writes this? My name is Dr. Adam McMaster. I’m an astronomer in the UK, where I mainly work on finding black holes. You can find me on BlueSky, @adammc.space.

Let me know what you think! You can send comments and feedback by hitting reply or by emailing [email protected].