- In astronomy and navigation, the celestial sphere is an abstract sphere that has an arbitrarily large radius and is concentric to Earth. All objects in the sky can be conceived as being projected upon the inner surface of the celestial sphere, which may be centered on Earth or the observer. If centered on the observer, half of the sphere would resemble a hemispherical screen over the observing location.
- NASA’s Webb Captures Dying Star’s Final ‘Performance’ in Fine Detail (webbtelescope.org)
NASA’s James Webb Space Telescope has cast the Southern Ring Nebula in an entirely new light. By observing the nebula in mid-infrared wavelengths, Webb has unveiled the second, dusty star at the center of the nebula in far more detail. The star closely orbits its companion as it periodically ejects layers of gas and dust. Together, the swirling duo have created a fantastic landscape of asymmetrical shells. Webb’s near-infrared light image hones in on “spotlights” from the stars, where light travels through holes in the nebula’s dusty ejections.