The green color is caused by interstellar gases in the pine tree-patterned composite image, but a bit of trickery had to be done for the view.
Although there are phenomena in outer space that provide a breathtaking image in themselves, it happens that space explorers use the sight of an existing formation to depict a figurative thing along the lines of some concept. One such example is one of the star clusters that make up NGC 2264, which is simply called the Christmas Tree Cluster due to its appearance and similarity to a real object.
Located approximately 2,500 light-years from Earth, the formation consists of two parts. One of these is the Christmas tree cluster of relatively young stars, which got its name from the location of the luminous celestial bodies in it and the green-tinged gas cloud stretching between them. The stars in the infrared range that make up the cluster are illuminated in white and create the “decorations” of the shape.
This year the This year’s NASA “Christmas tree” was created by supplementing the recordings of WIYN Observatory’s Chandra space telescope with data from the Two Micron All Sky Survey, i.e. 2MASS.
In the recordings published on the world wide web a few days ago, it can be seen that the stars in the green nebula sometimes shine with a white or blue color, which is caused by the pulsating brightness change cycles of the 1-5 million-year-old stars. This sight mostly results from the rotating motion of the stars: Sometimes the hot regions of the celestial body, other times darker regions turn towards us.
We’re celebrating the holiday season with a new image of the “Christmas Tree Cluster” — complete with blinking lights! This group of young stars, roughly 1-5 million years old, is located about 2,500 light-years from Earth: https://t.co/SnJFgSUY0h
Happy Holidays space fans!🎄 pic.twitter.com/sRgFZ5PlIE
— Chandra Observatory (@chandraxray) December 19, 2023
At other times, the light phenomenon has nothing to do with the stars in particular, but rather a disc that surrounds the object and periodically obscures it. In the most spectacular cases, the evolution of brightness is created by magnetic fields. In addition to creating so-called starspots, such regions also cause powerful eruptions.
Such young stars are known to be able to produce such powerful X-ray bursts on their surfaces. Such episodes are not rare and are much stronger than the one observed in the case of the comparatively Methuselah-aged Sun.