The European Southern Observatory (ESO) has released a beautiful photo taken by the FORS (FOcal Reducer and Spectrograph) instrument on the Very Large Telescope (VLT) of a faint planetary nebula called Abell 24.
This VLT image shows the planetary nebula Abell 24. Image credit: ESO.
Abell 24 resides some 1,730 light-years away in the constellation of Canis Minor.
Also known as PK 217+14.1, A66 24 and ARO 134, this object is something known as a planetary nebula — a burst of gas and dust created when a star dies and throws its outer layers into space.
Despite the name, planetary nebulae have nothing to do with planets.
The term was coined bythe German-born British astronomer William Herschel, who also famously discovered the ice giant Uranus.
In a time of low-resolution astronomy, these nebulous objects appeared to resemble giant planets swimming in a dark cosmos.
“A Sun-like star spends most of its life converting hydrogen into helium in its core,” ESO astronomers explained.
“In its twilight years the star runs out of fuel and becomes unbalanced; it can no longer resist the inward crush of gravity and the core begins to collapse.”
“The temperature in the core rises dramatically while the cooler outer layers expand, causing the entire star to bloat into a red giant.”
“When the Sun begins its transformation into a red giant it will expand to completely engulf the innermost planets and possibly also the Earth, growing to over 250 times its current radius.”
“Strong winds then expel the gaseous outer layers of the star, forming a shell of gas that spreads out into the vastness of space.”
“The red giant’s venting atmosphere will eventually expose its hot, luminous remnant core, which will emit fierce UV radiation and ionise the surrounding gas.”
