From all of us here at From Quarks to Quasars, we want to wish you a very merry Christmas (and a happy new yeeearrrr). Following along with the tradition of yesterday’s APOD, we wanted to feature another deep space region that has a festive, christmassy vibe. Alas.. no image is more appropriate than this; The Christmas Tree Cluster (also known as NGC 2264).
It occupies an expanse of space about 2600 light-years from Earth in the constellation of Monoceros. Other than the obvious Christmas Tree Cluster, this ‘heavenly’ area also includes several notable star-forming regions, like the Cone nebula, as well as the Fox Fur nebula.
Along with many other astronomical delights, William Herschel is credited with discovering NGC 2264. Upon his initial observation (when he was putting together his ‘great sky survey’ in the 18th century), he spotted a large, visually stunning star at the top of the nebula — resembling an angel ornament at the top of a celestial Christmas tree. It wasn’t until years later, when astronomers pointed modern telescopes to the area, that the multiple stars of the cluster emerged from the proverbial night time.
This area is dominated by the color red due to the intense ultraviolet radiation beaming from the stars within, which interacts with the hydrogen, causing it to glow. The small swatches of blue come from the central stars, which are much more massive than our sun is. All of them are metal-poor, which results in the stars burning rapidly and exploding in a supernova in just a fraction of the time it would take for stars of our sun’s caliber. The blue light emitted from these stars is scattered by the dust and gas clouds.
Download a larger image here.