Eight new super-hot stars

A sky survey image centred on the newly-discovered O(H) star SALT J203959.5-034117 (J2039) . An international team of astronomers has discovered eight of the hottest stars in the universe, all with surfaces hotter than 100,000 degrees Celsius. The work was published in Monthly Notices of the Royal Astronomical Society. The paper is based on data gathered using the Southern African Large Telescope (SALT), the largest single optical telescope in the southern hemisphere, with a 10m x 11m mirror. The study describes how a survey of helium-rich subdwarf stars led to the discovery of several very hot white dwarf and pre-white dwarf stars, the hottest of which has a surface temperature of 180,000 degrees Celsius. For comparison, the Sun-s surface is a mere 5,800 degrees. One of the stars identified is the central star of a newly discovered planetary nebula, which is one light year in diameter.