Comets are small celestial bodies composed of ice, dust, rock, and other volatile compounds. They orbit the Sun in elliptical or elongated trajectories. As a comet approaches the Sun, the frozen material on its surface heats up, begins to vaporize, and forms a luminous coma (a kind of atmosphere) around the comet’s nucleus. The nucleus […]
A supernova is an extremely bright and energetic explosion of a massive star. It marks the end of the life cycle of a star that must be at least about 1.4 times the mass of our Sun. The brightness of a supernova can, for a brief period, be as great as the entire galaxy in […]
Singleframe of the Iris Nebula with Meteor/Shooting Star. This time it was neither a plane nor a satellite.
I had the chance to visit the Astro-AG telescope at the Observatory Hoher List.
Planetary nebulae are glowing shells of gas and dust that are formed when a low-mass star reaches the end of its life and runs out of fuel to sustain nuclear fusion in its core. As the star’s core contracts and heats up, the outer layers of the star expand and are ejected into space, forming […]
Emission nebulae are interstellar clouds of gas and dust that emit light in various wavelengths due to the excitation of their atoms by high-energy radiation, such as ultraviolet light from nearby hot stars. When an atom in the nebula is excited by this energy, it absorbs the energy and then releases it in the form […]
Globular clusters are large, spherical clusters of stars that are gravitationally bound to each other. They are some of the oldest structures in the universe, with ages of up to 13 billion years, and are thought to have formed early in the history of the Milky Way and other galaxies. Globular clusters typically contain anywhere […]
Open clusters are groups of young stars that are loosely bound together by gravity. They typically contain anywhere from a few dozen to a few thousand stars, which are all thought to have formed from the same molecular cloud at roughly the same time. Open clusters are often found in the disk of a galaxy, […]
Galaxies are vast, gravitationally-bound systems of stars, gas, dust, and dark matter that make up the visible structure of the universe. They come in a wide variety of shapes and sizes, ranging from small, irregularly shaped dwarf galaxies to massive, spiral or elliptical galaxies that can contain hundreds of billions of stars. Galaxies are the […]
Reflection nebulae are clouds of gas and dust in space that are illuminated by nearby stars, causing the nebula to reflect the starlight and appear luminous. They are different from emission nebulae, which emit their own light due to ionization by nearby stars or other energy sources. Reflection nebulae are usually blue in color, as […]