NGC 2264, also known as the “Christmas Tree Cluster,” is a fascinating astronomical object located in the constellation Monoceros, approximately 2,300–2,600 light-years from Earth. It consists of two primary components: the Christmas Tree Cluster (a young open star cluster) and the Cone Nebula (a pillar-shaped region of gas and dust). Additionally, it includes the Fox Fur Nebula and the Stellar Snowflake Cluster, making it a rich region for star formation and study.

Key Features of NGC 2264

• Christmas Tree Cluster: This open cluster contains at least 600 stars, ranging in age from 1 to 5 million years. The bright blue stars form a triangular shape resembling a Christmas tree. The base of the “tree” is marked by S Monocerotis, a variable multiple-star system with a magnitude of 4.66²³⁴.
• Cone Nebula: This nebula is located at the top of the “tree” and spans about 7 light-years in length. It is a dense region where new stars are actively forming, similar to the Pillars of Creation³⁵.
• Fox Fur Nebula: A diffuse nebula below the Christmas Tree Cluster, its bright blue color results from light reflecting off dust particles³.
• Stellar Snowflake Cluster: This is another young star cluster within NGC 2264. Its name comes from its pinwheel-like appearance in infrared images, where young red stars contrast with older blue ones²³.

Physical Characteristics

• Distance: Approximately 2,300–2,600 light-years.
• Size: The entire region spans about 30 light-years across.
• Magnitude: Apparent visual magnitude of 3.9, making it visible under dark skies with binoculars or small telescopes.
• Composition: The region is rich in gas and dust clouds, primarily hydrogen and helium, which fuel ongoing star formation¹³⁶.

Discovery and Observation

NGC 2264 was discovered by William Herschel in January 1784. Its iconic Christmas tree shape is most apparent in visible light images. The red glow of the nebula comes from hydrogen gas ionized by ultraviolet radiation from newborn stars³⁵. This festive appearance has made it a popular target for astrophotography.

Scientific Importance

NGC 2264 provides astronomers with a detailed view of star formation processes. It contains both massive stars (up to seven times the Sun’s mass) and smaller stars (less than one-tenth the Sun’s mass), offering insights into stellar evolution across a range of masses⁶⁷. The ratio of brown dwarfs to stars in this region also contributes to studies on substellar objects².

Image Details

The Image above was take with a RedCat 51 and ASi 2600mm with ZWO filters and EFW. The scope was mounted on iOptron HEM27ec. The image was a combination of 15 x 5minute subframe and processed with PixInsight.

Citations:

1. https://theskylive.com/sky/deepsky/ngc2264-christmas-tree-cluster-object
2. https://en.wikipedia.org/wiki/NGC_2264
3. https://www.galactic-hunter.com/post/ngc2264
4. https://www.constellation-guide.com/christmas-tree-cluster/
5. https://www.skyatnightmagazine.com/space-science/christmas-tree-cluster-ngc-2264
6. https://chandra.harvard.edu/photo/2023/ngc2264/
7. https://www.nasa.gov/image-article/telescopes-illuminate-christmas-tree-cluster/
8. https://www.planetary.org/space-images/ngc-2264-the-christmas-tree-cluster