This image compares two drastically different portraits of the Stingray nebula captured by NASA’s Hubble Space Telescope 20 years apart. The image on the left, taken with the Wide Field and Planetary Camera 2 in March 1996, shows the nebula’s central star in the final stages of its life. The gas being puffed off by the dying star is much brighter when compared to the image of the nebula at the right, captured in January 2016 using the Wide Field Camera 3. (NASA, ESA, B. BALICK (UNIVERSITY OF WASHINGTON), M. GUERRERO (INSTITUTO DE ASTROFÍSICA DE ANDALUCÍA), AND G. RAMOS-LARIOS (UNIVERSIDAD DE GUADALAJARA))
All stars, even our Sun, will someday eventually die.
After burning on the main sequence for billions of years, the Sun will expand into a red giant, switch to helium burning, move to the asymptotic branch, and then eject its outer layers. As the core contracts, it heats up, illuminating the gas in a planetary nebula. Over about 20,000 years, that nebula will fade away, eventually becoming invisible. (WIKIMEDIA COMMONS USER SZCZUREQ)
Upon exhausting their core’s nuclear fuel, Sun-like stars die in a predictable fashion.
Near the end of a Sun-like star’s life, it begins to blow off its outer layers into the depths of space, forming a protoplanetary nebula like the Egg Nebula, seen here. Its outer layers have not yet been heated to sufficient temperatures by the central, contracting star to create a true planetary nebula just yet. (NASA AND THE HUBBLE HERITAGE TEAM (STSCI / AURA), HUBBLE SPACE TELESCOPE / ACS)
The core contracts, forming white dwarfs, which heats and illuminates the blown-off outer layers, creating planetary nebulae.
This Hubble Space Telescope image of the Helix Nebula shows a typical planetary nebula/white dwarf combination: the result of a Sun-like star reaching the end of its life. The central white dwarf is much fainter than a standard star, but is very hot and emits ionizing radiation. The illuminated nebula is made of ejecta from the star’s outer layers, and is illuminated by the central stellar remnant. (NASA, ESA, AND C.R. O’DELL (VANDERBILT UNIVERSITY))
These nebulous remnants persist for ~20,000 years, experiencing slow, gradual changes.
After 20 years of Hubble observations, however, the Stingray Nebula appears doubly special.
The Universe is: Expanding, cooling, and dark. It starts with a bang! #Cosmology Science writer, astrophysicist, science communicator & NASA columnist.
