Data recently returned for d Cep from the Chandra X-ray Observatory, combined with previous X-ray measures secured with the XMM-Newton X-ray satellite, have shown that d Cep has X-ray variations occurring in accord with the supergiant star's 5.4 day pulsation period. X-rays are observed at all phases of the star’s pulsations, but sharply rise by ~400% near the times when the star swells to its maximum diameter of about 45 times that of the Sun.
Submitted by stellakafka on Thu, 03/23/2017 - 13:21
Twenty-three new objects have been added to the growing collection of stars observed to have unusual dips in their light curves. A recent study examines these stars and the potential causes of their strange behavior.
Astronomers spot an intense explosion of a massive star, which, according to records, experienced frequent eruptions for at least 20 years. The analysis of the outburst does not allow to discern between a real supernova - an explosive event marks the end of a star - or a giant eruption implying a massive change in the star’s evolutionary course