How dust affects light reaching us from stars

Researchers have showed that the laws used since 1989 to calculate the extinction of light produced by dust had serious limitations.

Jesus Ma'z Apellaniz, researcher at the Institute of Astrophysics of Andalusia (IAA-CSIC) in charge of the publication, said in the range of wavelengths that our eyes perceive-the visible light-of every billion photons that a star in the center of the Milky Way emits, only one reaches our eyes.

He said that this is an extreme example of how dust affects the light of stars, a phenomenon that takes place in every single environment, albeit with less intensity.

The researchers began their work six years ago. They started with a sample of one thousand stars and narrowed it down to eighty three "ideal" objects.

After subjecting the sample to different experiments which confirmed the great deviations that the laws of 1989 produce, they developed new versions of the laws which diminish, for instance, the temperature errors by two thirds.

In fact, the results yielded by the new laws are nearly as precise as those obtained through spectroscopy, which remains the most reliable method for detailed observations. "Nevertheless, this study makes it possible to obtain acceptable temperature estimates using photometry, with the advantage that this technique allows one to study more objects per unit of time," underlines Ma'z Apellaniz (IAA-CSIC).