A pulsating stellar relic
This NASA/ESA Hubble Space Telescope image shows the planetary nebula NGC 2452, located in the southern constellation of Puppis. The blue haze across the frame is what remains of a star like our Sun after it has depleted all its fuel. When this happens, the core of the star becomes unstable and releases huge numbers of incredibly energetic particles that blow the star’s atmosphere away into space.
At the centre of this blue cloud lies what remains of the nebula’s progenitor star. This cool, dim, and extremely dense star is actually a pulsating white dwarf, meaning that its brightness varies over time as gravity causes waves that pulse throughout the small star’s body.
NGC 2452 was discovered by Sir John Herschel in 1847. He initially defined it as “an object whose nature I cannot make out. It is certainly not a star, nor a close double star […] I should call it an oblong planetary nebula”. To early observers like Herschel with their smaller telescopes, planetary nebulae resembled gaseous planets, and so were named accordingly. The name has stuck, although modern telescopes like Hubble have made it clear that these objects are not planets at all, but the outer layers of dying stars being thrown off into space.
Image credit: ESA/Hubble & NASA; Acknowledgements: Luca Limatola, Budeanu Cosmin Mirel
M7, The Ptolomy Cluster
M7 is a very bright open cluster in Scorpius. Very close to the “Sting” formed by the bright stars Shaula and Lesath. Visible on the left of the photo.
The Emu Eats the Fly
The dark Coalsack nebula and the bright star just on its border look like the head of a bird that is pointing directly to the “Dark Doodad” nebula in Musca. A strange scene in the southern Milky Way.
The Pipe Nebula
The “pipe” is an enormous area towards the center of the Milky Way where dust hides the stars in the background.
Photographed by Luis Argerich
We look up at the stars and see such different things.
IC 2118- The Witch Head Nebula in Eridanus by Scott Rosen
IC 2118, is an extremely faint reflection nebula believed to be an ancient supernova remnant or gas cloud illuminated by nearby supergiant star Rigel in Orion. It lies in the Eridanus constellation, about 900 light-years from Earth.