NASA Brings “Christmas Tree Crowd” to Life

NGC 2264, the “Christmas Tree Cluster” is a star cluster. milky wayDepicted in the newly updated film as a cosmic Christmas tree.

• NGC 2264 is a cluster of young stars, colored and rotated to emphasize the nickname “Christmas Tree Cluster”.
• This composite image includes X-rays from Chandra (blue and white), optical data from WIYN (green gas), and infrared data from 2MASS (white stars).
• Compared to the Sun’s age of 5 billion years, this cluster of stars is between one and five million years old.
• Young stars are turbulent and produce strong bursts of X-rays and other types of light, but not in any coordinated fashion as shown in the animation.

The Cosmic Christmas Tree: A Star View of NGC 2264

This new image of NGC 2264, also known as the “Christmas Tree Cluster,” shows the shape of a cosmic tree with a twinkle of starlight. NGC 2264 is actually a cluster of young stars – about one to five million years old – in our own Milky Way, about 2,500 light-years from Earth. The stars in NGC 2264 range from smaller to larger than the Sun, with some ranging from less than one-tenth the mass of the Sun to others as much as seven solar masses.

A festive composition image: colors and rotation

This new composite image enhances the unity of the Christmas tree through choices of color and rotation. Blue and white lights (flashing in the animated version – see video below) emit X-rays detected by young stars. NASAChandra X-ray Lab. Optical data from the National Science Foundation-supported WIYN 0.9-meter telescope at Kitt Peak show the gaseous nebula as green as the “pine needles” of a tree. Finally, infrared data from the Two Micron All Sky Survey show foreground and background stars in white. This image has been rotated upwards 160 degrees from the astronomer’s standard north, so that the top of the tree appears to be toward the top of the image.

This composite image shows a Christmas tree assembly. The blue and white lights (flashing in the animated version of this image) are young stars that give off X-rays detected by NASA’s Chandra X-ray Observatory. Optical data from the National Science Foundation’s WIYN 0.9-meter telescope at Kitt Peak show gas in the nebula in green, resembling the “pine needles” of a tree, and infrared data from the Two Micron All Sky Survey show foreground and background stars. White. The image has been rotated 160 degrees clockwise from the astronomer’s standard north, so that the top of the tree appears to be toward the top of the image.

Stellar dynamics and observational techniques

Young stars, like the one in NGC 2264, are volatile and produce strong flares in X-rays and other types of contrasts seen at different wavelengths of light. However, the integrated, luminous contrasts shown in this animation are artificial, to emphasize the locations of the stars seen in X-rays and to illustrate the object’s resemblance to a Christmas tree. In fact the variations of the stars are not synchronized.

The variations observed by Chandra and other telescopes are caused by various processes. Some of this is related to activity involving magnetic fields, including flares like those caused by the Sun – but much more powerful – and hot spots and dark regions on the surface of stars that move in and out of view as stars rotate. Changes can also occur in the thickness of the gas that obscures the stars, and in the amount of material still falling onto the stars from the surrounding gaseous disks.

NASA’s Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts and flight operations from Burlington, Massachusetts.