NASA has unveiled a captivating image of NGC 2264, famously known as the "Christmas Tree Cluster," resembling a cosmic tree adorned with stellar lights. Situated in our Milky Way, approximately 2,500 light-years away from Earth, NGC 2264 is, in fact, a cluster of young stars aged between one and five million years.
These stars exhibit a diverse range of sizes, with some having less than a tenth of the sun's mass, while others boast about seven solar masses. To enhance the resemblance to a Christmas tree, this composite image features clever color choices and rotation.
The blue and white lights, which appear to blink in the animated version of the image, represent young stars emitting X-rays, a phenomenon detected by NASA's Chandra X-ray Observatory. The green hue in the image, derived from optical data captured by the National Science Foundation's WIYN 0.9-meter telescope, corresponds to the "pine needles" of the cosmic tree. Additionally, the white dots signify foreground and background stars as observed by the Two Micron All Sky Survey.
While the coordinated, blinking variations in this animation are artificial, designed to emphasize the X-ray-emitting stars and highlight the tree's likeness, the stars' actual variations are not synchronized. These fluctuations result from various processes, including magnetic field-related activities such as powerful flares, hot spots, and dark regions on the stars' surfaces, all of which come in and out of view as the stars rotate.