Our first story of the day takes our oft-stated quandary that no one really knows how planets form and extends that problem out to include the formation of stars as well. We have a big picture understanding: there are giant molecular clouds of gas and something happens that causes pockets of material to fragment and collapse into stars. That much, observationally is clear. According to new research to appear in The Astrophysical Journal, what happens next is not at all what was expected. 

We had thought that stars would clear away the clouds of material around them through a combination of gravitationally pulling in material to form a cavity and then blasting that cavity larger with their stellar winds and jets. This new work, however, looks at high-resolution images from the Hubble and Herschel space telescopes and examines the differences in cavity structure around stars of a variety of different ages. According to lead researcher Nolan Habel: Our observations indicate there is no progressive growth that we can find, so the cavities are not growing until they push out all of the mass in the cloud. So, there must be some other process going on that gets rid of the gas that doesn’t end up in the star. 

What that process is? No idea. But if the JWST actually launches later this year and works as hoped, it may be able to spy the answer.

More Information

NASA press release

“An HST Survey of Protostellar Outflow Cavities: Does Feedback Clear Envelopes?,” Nolan M. Habel et al., to be published in The Astrophysical Journal (preprint on arxiv.org)