In 2023, amateur astronomer Dana Patchick was looking through images from the Wide-field Infrared Survey Explorer archive and discovered a diffuse, circular object in the constellation of Cassiopeia.
Astronomy
Nov 16, 2023
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Astronomers have found plenty of white dwarf stars surrounded by debris disks. Those disks are the remains of planets destroyed by the star as it evolved. But they've found one intact Jupiter-mass planet orbiting a white ...
Astronomy
Nov 2, 2023
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Stars like our sun end their lives as white dwarfs. Some of them are surrounded by a planetary nebula consisting of gas ejected by the dying star shortly before its death. An international research team led by Professor Klaus ...
Astronomy
Oct 11, 2023
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NASA's James Webb Space Telescope obtained images of the Ring Nebula, one of the best-known examples of a planetary nebula. Much like the Southern Ring Nebula, one of Webb's first images, the Ring Nebula displays intricate ...
Astronomy
Aug 21, 2023
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NASA's James Webb Space Telescope (JWST) has recorded breathtaking new images of the iconic Ring Nebula, also known as Messier 57.
Astronomy
Aug 3, 2023
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The glowing nebula IC 2220, nicknamed the Toby Jug Nebula owing to its resemblance to an old English drinking vessel, is a rare astronomical find. This reflection nebula, located about 1200 light-years away in the direction ...
Astronomy
Jul 13, 2023
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A portion of the open cluster NGC 6530 appears as a roiling wall of smoke studded with stars in this image from the NASA/ESA Hubble Space Telescope. NGC 6530 is a collection of several thousand stars lying around 4,350 light-years ...
Astronomy
Dec 19, 2022
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From high atop a mountain in the Chilean Andes, the Dark Energy Camera has snapped more than one million exposures of the southern sky. The images have captured around 2.5 billion astronomical objects, including galaxies ...
Astronomy
Oct 4, 2022
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Astronomers have performed an astro-photometric study of an open cluster known as Messier 37. One of the main results of this research is the finding that Messier 37 hosts a large and evolved planetary nebula. The study was ...
Some stars save the best for last.
Astronomy
Jul 12, 2022
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A planetary nebula is an emission nebula consisting of a glowing shell of gas and plasma formed by certain types of stars when they die. The name originated in the 18th century because of their similarity in appearance to giant planets when viewed through small optical telescopes, and is unrelated to the planets of the solar system. They are a relatively short-lived phenomenon, lasting a few tens of thousands of years, compared to a typical stellar lifetime of several billion years.
At the end of the star's life, during the red giant phase, the outer layers of the star are expelled via pulsations and strong stellar winds. Without these opaque layers, the remaining core of the star shines brightly and is very hot. The ultraviolet radiation emitted by this core ionises the ejected outer layers of the star which radiate as a planetary nebula.
Planetary nebulae are important objects in astronomy because they play a crucial role in the chemical evolution of the galaxy, returning material to the interstellar medium which has been enriched in heavy elements and other products of nucleosynthesis (such as carbon, nitrogen, oxygen and calcium). In other galaxies, planetary nebulae may be the only objects observable enough to yield useful information about chemical abundances.
In recent years, Hubble Space Telescope images have revealed many planetary nebulae to have extremely complex and varied morphologies. About a fifth are roughly spherical, but the majority are not spherically symmetric. The mechanisms which produce such a wide variety of shapes and features are not yet well understood, but binary central stars, stellar winds and magnetic fields may all play a role.
This text uses material from Wikipedia, licensed under CC BY-SA
