ROSAT/ T-Tauri stars in Chamaeleon
Credit: ROSAT Project and MPE

Naked Newborns

Stars are formed out of huge, massive clouds of gas and dust. These clouds begin to gravitationally collapse, forming a dense core which will eventually become a star. To understand how this process occurs astronomers need to be able to identify newly formed stars. One good place to look for new stars is near cold, thick interstellar clouds. One good way to look for these new stars is X-ray imaging. X-ray imaging is useful since young stars are typically bright X-ray sources due to enhanced stellar activity, and also since X-rays have great penetrating power and can pass through even the thickest of interstellar clouds. The image above shows young stars near a molecular cloud complex in the constellation of Chamaeleon. These stars were identified as bright X-ray sources by ROSAT during ROSAT's All-Sky Survey, and ground-based followup observations confirmed them as young stars with ages between 300,000 and 10 million years old. Surprisingly many of these stars are found outside the molecular clouds; astronomers speculate that either these "bare" stars were ejected from their birth clouds, or else the birth clouds were evaporated by the light from the star.

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Each week the HEASARC brings you new, exciting and beautiful images from X-ray and Gamma ray astronomy. Check back each week and be sure to check out the HEAPOW archive!

Page Author: Dr. Michael F. Corcoran
Last modified August 27, 2001