Thursday, May 19, 2022

The Stingray Nebula

The Stingray  Nebula is a planetary nebula located 18,000 light-years away from Earth, visible in the constellation Ara.

The nebula's progenitor star was first observed in 1967 and was classified as a class A or B main sequence star. When observed four years later it was found that the star had evolved, becoming a blue giant with a temperature surface of 22000 degrees Kelvin. Observing it in 1989 it was clear that the star had ejected part of its surface layers into space, forming a planetary nebula.

 Its surface temperature had meanwhile increased to 60,000 Kelvin. The new nebula was then studied in 1996 by the Hubble Telescope.

The telescope returned to photographing the nebula twenty years later, in 2016, and what was seen is something unique. The nebula had in fact completely changed its appearance, decreasing its brightness by a factor of 1000. It was the first time that it was possible to follow the evolution and changes of a nebula in such a short period of time.

Furthermore, an even more surprising aspect, contrary to what has always been thought, the decrease in brightness of a nebula is not always connected to its expansion. Its dimensions, as you can see, have remained constant.

If its brightness continues to decline at this rate, it is estimated that within another twenty years the nebula will be too dim to be observed.

Credit: NASA, ESA, B. Balick, M. Guerrero, G. Ramos-Larios.

0 commenti:

Post a Comment