New research showed the Rosette Nebula is shaped more like a thin disk than than a thick donut. Photo by Nick Wright/Keele University
Feb. 13 (UPI) -- The size of the empty cavity at the center the Rosette Nebula -- a hollow heart -- has long puzzled astronomers. But scientists now have some answers thanks to a new survey of the interstellar cloud.
Nebula models suggest Rosette's central cavity should be larger than it is based on the size of its central stars. But new analysis suggests the discrepancy is the product of a misunderstanding of Rosette's shape.
The Rosette Nebula, or Caldwell 49, is found 5,000 light-years from Earth in the Milky Way. It's named for its rose-like shape.
"The massive stars that make up the Rosette Nebula's central cluster are a few millions of years old and halfway through their lifecycle," Christopher Wareing, an astronomer at Leeds University, said in a news release. "For the length of time their stellar winds would have been flowing, you would expect a central cavity up to ten times bigger."
Stellar winds and radiation from a nebula's stellar inhabitant impact its size and structure, including the size and shape of its central cavity.
Previous surveys of Rosette suggested the nebula was a thick, donut-like shape, but the latest analysis proved the nebula is actually relatively thin -- more a disk than a donut.
When astronomers reprogrammed their model of Rosette to account for its thin, disk-like shape, they minimized the discrepancy.
"We simulated the stellar wind feedback and formation of the nebula in various molecular cloud models including a clumpy sphere, a thick filamentary disc and a thin disc, all created from the same low density initial atomic cloud," Wareing said. "It was the thin disc that reproduced the physical appearance -- cavity size, shape and magnetic field alignment -- of the nebula, at an age compatible with the central stars and their wind strengths."
The accuracy of the new model was improved by fresh data from the Gaia survey, which included observation of several stars in the nebula.
Astronomers described their improved model in the journal Monthly Notices of the Royal Astronomical Society.
Scientists credited improving technology for the efficiency with which the new research was conducted.
"The fact that the Rosette Nebula simulations would have taken more than five decades to complete on a standard desktop computer is one of the key reasons we provide powerful supercomputing research tools," said astronomer Martin Callaghan. "These tools enabled the simulations of the Rosette Nebula to be done in a matter of a few weeks."