Scientists may have designed a new method that may revolutionize how we tell the distances between planetary nebulae. Researchers believe that the new research could be huge when it comes to understanding where exactly in the universe these planetary nebulae are located.
Planetary nebulae aren't actually planets. In fact, they have very little to do with planets. They're actually glowing spheres of ionized gas. These spheres, not surprisingly, resembled planets to early observers. These objects are actually the ejected shrouds of dying stars, though they've been poorly studied mostly because it's difficult to determine how far they are from the planet Earth.
In this latest study, researchers found a new way to estimate these distances. The technique relies, in total, on three sets of data. First, the size of the object in the sky has to be determined from high resolution surveys. Then, scientists need to measure how bright the object is in the red hydrogen-alpha emission line. Finally, they have to estimate the dimming toward the nebula caused by interstellar-reddening.
The three sets of data allow researchers to calculate surface brightness - radius relation. This, in turn, allows scientists to calculate accurate distances between planetary nebulae and Earth. In fact, the new distance scale works over a factor of more than six powers of ten in surface brightness, and actually provides distances that are accurate to 20 percent. This is a major advance on previous estimators.
"Measuring distances to galactic 'planetary nebulae' has been an intractable problem for many decades, because of the extremely diverse nature of both the nebulae themselves and their central stars," said David Frew of the University of Hong Kong, one of the researchers. "However, understanding their true nature and physical characteristics depends crucially on knowing their distance. With our significantly improved distance estimates, we can finally provide more meaningful values for many key parameters of scientific interest."
The findings are huge when it comes to better understanding planetary nebulae. More specifically, they may allow researchers to investigate these features to better understand the life and the death of a star.
The findings were published in the April edition of the journal Monthly Notices of the Royal Astronomical Society.
