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Stellar halo. A stellar halo is the component of a galaxy 's galactic halo that contains stars. The stellar halo extends far outside a galaxy's brightest regions and typically contains its oldest and most metal poor stars.
The timeline of the early universe outlines the formation and subsequent evolution of the Universe from the Big Bang (13.799 ± 0.021 billion years ago) to the present day. An epoch is a moment in time from which nature or situations change to such a degree that it marks the beginning of a new era or age . Times on this list are measured from ...
It is approximately 2,500 light-years away. NGC 6326, a planetary nebula with glowing wisps of outpouring gas that are lit up by a binary [3] central star. A planetary nebula is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives. [4]
Stellar molecules are molecules that exist or form in stars. Such formations can take place when the temperature is low enough for molecules to form – typically around 6,000 K (5,730 °C; 10,340 °F) or cooler. [1] Otherwise the stellar matter is restricted to atoms and ions in the forms of gas or – at very high temperatures – plasma .
Five-pointed star. A five-pointed star (☆), geometrically an equilateral concave decagon, is a common ideogram in modern culture. Comparatively rare in classical heraldry, it was notably introduced for the flag of the United States in the Flag Act of 1777 and since has become widely used in flags.
Galaxy. NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 55,000 light-years in diameter and approximately 60 million light-years from Earth. A galaxy is a system of stars, stellar remnants, interstellar gas, dust, and dark matter bound together by gravity.
The most widely accepted model of planetary formation is known as the nebular hypothesis. This model posits that, 4.6 billion years ago, the Solar System was formed by the gravitational collapse of a giant molecular cloud spanning several light-years. Many stars, including the Sun, were formed within this collapsing cloud.
Accretion (astrophysics) In astrophysics, accretion is the accumulation of particles into a massive object by gravitationally attracting more matter, typically gaseous matter, into an accretion disk. [1] [2] Most astronomical objects, such as galaxies, stars, and planets, are formed by accretion processes.