Nombre total de pages vues

Affichage des articles dont le libellé est ASTRONOMY - Stars. Afficher tous les articles
Affichage des articles dont le libellé est ASTRONOMY - Stars. Afficher tous les articles

10/07/2023

ASTRONOMY - Stars, Dust and Nebula in NGC 6559

 2023 July 10

A busy star formation region is shown highlighted by red glowing clouds
and dark ominously-shaped dust.
Please see the explanation for more detailed information.

Stars, Dust and Nebula in NGC 6559
Image Credit & Copyright: Adam BlockTelescope Live

Explanation: When stars form, pandemonium reigns. A textbook case is the star forming region NGC 6559. Visible in the featured image are red glowing emission nebulas of hydrogen, blue reflection nebulas of dust, dark absorption nebulas of dust, and the stars that formed from them. The first massive stars formed from the dense gas will emit energetic light and winds that erode, fragment, and sculpt their birthplace. And then they explode. The resulting morass can be as beautiful as it is complex. After tens of millions of years, the dust boils away, the gas gets swept away, and all that is left is a bare open cluster of stars.

11/10/2022

ASTRONOMY - Stars, Dust, Pillars, and Jets in the Pelican Nebula

 2022 October 11

The featured image shows a close up of the Pelican Nebula
highlighted by several dark pillars, one of which spouts jets
on either side.
Please see the explanation for more detailed information.

Stars, Dust, Pillars, and Jets in the Pelican Nebula
Image Credit & Copyright: Adriano Almeida

Explanation: What dark structures arise within the Pelican Nebula? On the whole, the nebula appears like a bird (a pelican) and is seen toward the constellation of a different bird: Cygnus, a Swan. But inside, the Pelican Nebula is a place lit up by new stars and befouled by dark dust. Smoke-sized dust grains start as simple carbon compounds formed in the cool atmospheres of young stars but are dispersed by stellar winds and explosions. Two impressive Herbig-Haro jets are seen emitted by the star HH 555 on the right, and these jets are helping to destroy the light year-long dust pillar that contains it. Other pillars and jets are also visible. The featured image was scientifically-colored to emphasize light emitted by small amounts of heavy elements in a nebula made predominantly of the light elements hydrogen and helium. The Pelican Nebula (IC 5067 and IC 5070) is about 2,000 light-years away and can be found with a small telescope to the northeast of the bright star Deneb.

SANTé/MEDECINE - A la découverte de l'oreille - L'oreille externe

L' oreille externe comprend le pavillon qui entoure le canal qui mène au tympan . Dans l' oreille moyenne se trouvent les osselets...