Starship Asterisk*

Simulations solve a 20-year-old riddle about why nebulae around masssive stars don't disappear.

The birth of the most massive stars -- those ten to a hundred times the mass of the Sun -- has posed an astrophysical riddle for decades. Massive stars are dense enough to fuse hydrogen while they're still gathering material from the gas cloud, so it was a mystery why their brilliant radiation does not heat the infalling gas and blow it away.

New simulations by researchers affiliated with the University of Heidelberg, American Museum of Natural History, the National Autonomous University of Mexico, and the Harvard-Smithsonian Center for Astrophysics show that as the gas cloud collapses, it forms dense filamentary structures that absorb the star's radiation when it passes through them. A result is that the surrounding heated nebula flickers like a candle flame.

• The Astrophysical Journal, Vol 711, Num 2, Page 1017,
  doi: 10.1088/0004-637X/711/2/1017, 2010 March 10

How the brightest stars in the sky are made has long defied explanation...until now.

• How the largest stars get so big has been a troubling question for about 20 years.
• A new simulation reveals how they grow without blasting away the material they need.
• Massive stars create filaments of material that help them grow -- and trigger other stars to form.