Physics Photo of the Week

December 23, 2022

The Christmas Tree Nebula - Photo by Donald Collins with the College View Observatory

Merry Christmas Everyone! The Christmas Tree Nebula, part of NGC 2264 consists of a cosmic cloud composed of dust and hydrogen in the constellation Monosoros - just east of Orion.  This gas/dust cloud is a busy center of extensive star formation.  The dust and hydrogen gas have been contracting due to their own self-gravity and clumps become extremely dense and begin to form new stars in the centers of the dust cloud.  Like the nearby Orion Nebula (PPOW for February 8, 2019), this nebula is a stellar nursery where hot, giant, blue stars are "born".  The Christmas Tree cloud resembles a dust "pillar", which is also seen in the Orion Nebula as a dark shadow.  The bright halo surrounding the Christmas Tree cloud is a massive cloud of hydrogen that glows red and emits the red glow characteristic of a hydrogen lamp - a glass tube filled with hydrogen gas with electrodes in it that is excited to glow when a high voltage is applied to the electrodes - like a "neon sign".  Scattered throughout the cloud, not obliterated by the dust "Christmas tree" is a star cluster of the new bright stars called NGC 2022.

This nebula and cluster is about 2350 light years from Earth.  The nebula cloud is about 14 light years across.


If clear weather permits, we will work on photographing a color image of
this object from the College View Observatory.  The nearby stars, were born "recently" - several million years ago.  The ultraviolet radiation from the extreme high temperatures of the massive new stars also tends to "sculpt" the nearby cloud remnants and force the cloud "tops" to have a rounded appearance and for the edges to glow.  The "Horsehead Nebula" - also in Orion - is another example pictured at right which may be chosen to illustrate the colors in these clouds.

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  Physics Photo of the Week is published weekly during the academic year on Fridays by the Warren Wilson College Physics Department. These photos feature interesting phenomena in the world around us.  Students, faculty, and others are invited to submit digital (or film) photographs for publication and explanation. Atmospheric phenomena are especially welcome. Please send any photos to dcollins@warren-wilson.edu.

All photos and discussions are copyright by Donald Collins or by the person credited for the photo and/or discussion.  These photos and discussions may be used for private individual use or educational use.  Any commercial use without written permission of the photoprovider is forbidden.

Observers are invited to submit digital photos to:

 

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