(ORDO NEWS) — Many processes in the Universe take place on gigantic time scales, taking billions of years, therefore, in order to study such a process, astronomers have to prove, using the example of several different space objects, that these objects are a reflection of the same general process at different stages. Very rarely is it possible to capture the evolution of an astronomical object in real time. But just such an event was witnessed by researchers who analyzed the results of observing the planetary Skat nebula using the NASA / ESA Hubble Space Telescope.
The planetary nebula is the remnants of a star that shed its outer shells at the last stages of its life cycle. The Stingray Nebula was named one of the youngest known planetary nebulae when, in 1998, the Hubble captured the last stages of the evolution of a dying star. Now, 20 years after the first observations, the Stingray Nebula has attracted the attention of astronomers for a different reason.
Pictures taken in 2016 (see photo) show significant dimming of the nebula over the past two decades. In addition, the shells of gas surrounding the central star have changed, and are now significantly less clear and stand out from the surrounding space, as before. Such visual changes in the nebula have never before been noted in the entire history of space observations. In terms of numbers, for example, the intensity of oxygen lines dropped by about 1,000 times over this twenty-year period, note the authors of a new study led by Bruce Balick of the University of Washington in Seattle, USA.
Typically, a planetary nebula grows larger as it evolves, rather than smaller, as is the case with the Stingray Nebula, Balik explains. The abnormal and rapid evolution of the Ray Nebula may be related to the unusual nature of the central star SAO 244567, which was studied in 2016 by another team led by Nicole Reindl of the University of Potsdam in Germany. In their study, Reindl and her colleagues show that the star’s temperature soared from about 22,000 degrees Celsius to 60,000 degrees Celsius between 1971 and 2002, after which the star began to cool. According to Reindl’s hypothesis, this temperature spike is associated with a thermonuclear explosion corresponding to the burning of helium on a star.
Balik’s work appeared on the arxiv.org pre-publication server.
Contact us: [email protected]