NASA’s Spitzer Space Telescope has one-upped itself with a fabulous new stellar family mosaic of stars that lie deep within the Northern constellation of Cepheus.
Compiled using archival data from Spitzer’s Infrared Array Camera (IRAC) and the Multiband Imaging Photometer (MIPs), the large celestial image includes multiple clusters of stars from the same dense clumps of gas and dust. Because these star clusters vary in age, the mosaic is what NASA calls a real generational stellar portrait .
Due to the fact that stellar formation and evolution take place on timescales that are incomprehensibly long by human standards, in an effort to understand them, Earth-bound astronomers are forced to rely on data gleaned from observations of stars at various stages of their evolution. That is, from their earliest moments as nuclear furnaces to their last dying days.
A smattering of baby stars appear in these images as red and yellow dots and make up a dense region of gas and dust known as Cepheus C, notes NASA. Part of the larger Cepheus OB3 molecular cloud, Cepheus C stretches some six light years in diameter and acts as a veritable incubator for young stars.
A second large nebula appears in the right of the image, and is characterized by a star cluster located just above it, says NASA. Dubbed Cepheus B, the cluster lies a few thousand light years away and is made up of stars that are only four to five million years old. That’s just slightly older, says NASA, than the young stellar objects found in Cepheus C. The small, red hourglass shape just below Cepheus C is a massive star designated as V374 Ceph, says NASA, and is thought to be surrounded by a disk of dark, dusty material.
In the earliest stages of formation, stars are called young stellar objects (YSOs), as Caltech astronomer Luisa Rebull noted in a Caltech proposal detailing Cepheus C search strategies. In the past two decades, she writes that astronomers have uncovered diverse variations in the brightnesses of YSOs over timescales of days to years. Such variations alone enable astronomers to better understand the structure and behavior of young stellar objects in their very earliest stages of formation, Rebull notes. Stars form out of large clouds of interstellar dust and gas that have been pulled together by gravity over millions of years, she writes, with the initial gravitational collapse leaving a cocoon of gas and dust surrounding the forming star.
As part of NASA’s NITARP (NASA/IPAC Teach Archive Research Program), during 2016 and 2017, high school students combed through Spitzer images of Cepheus-C to find identify young stellar objects. With guidance from Rebull, students and teachers were able to spot more than 100 such young objects that had previously proved elusive.