Four luminous blue variables found to be much closer than previously assumed
http://phys.org/news/2016-10-luminous-blue-variables-closer-previously.html
A new study based on the first Gaia data release (DR1) reveals more accurate measurements of the distance of four canonical luminous blue variables
(LBVs) in the Milky Way galaxy. According to a research paper published Oct. 20 on the arXiv server, they are much closer to Earth than previously thought.
Published on Sept. 14, 2016, DR1 contains a catalog of over 1 billion stars with precise measurements of their brightness and positions in the sky. These data
were obtained by ESA's Gaia satellite, which is completing the first-ever "galactic census"—the most detailed three-dimensional map of the Milky Way ever made.
The release of DR1 offers the scientific community an excellent opportunity to improve knowledge of our stellar environment and to redefine some previous
calculations.
Combing through the data obtained by Gaia, Nathan Smith of the Steward Observatory in Arizona and Keivan Stassun of Vanderbilt University in Nashville, Tennessee,
have searched for LBVs and LBV candidates. These massive evolved stars showcase unpredictable and sometimes dramatic variations in both their spectra and their
brightness. Their strong mass loss is believed to play a critical role in the evolution of massive stars, however the exact role LBVs play and the physics of
their instability are still uncertain.
