Star
Astronomical object comprising a luminous spheroid of plasma held together by its gravity.
- Star500 related topics
Star formation
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as "stellar nurseries" or "star-forming regions", collapse and form stars.
Fixed stars
The fixed stars (stellae fixae) compose the background of astronomical objects that appear not to move relative to one another in the night sky, unlike the foreground of Solar System objects, which appear to move.
Generally, the fixed stars are taken to include all stars other than the Sun.
Star catalogue
A star catalogue (Commonwealth English) or star catalog (American English) is an astronomical catalogue that lists stars.
Main sequence
In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness.
Thermonuclear fusion
Process of atoms combining or “fusing” together with huge amounts of heat.
There are two forms of thermonuclear fusion: uncontrolled, in which the resulting energy is released in an uncontrolled manner, as it is in thermonuclear weapons ("hydrogen bombs") and in most stars; and controlled, where the fusion reactions take place in an environment allowing some or all of the energy released to be harnessed for constructive purposes.
Hydrogen
Chemical element with the symbol H and atomic number 1.
Stars such as the Sun are mainly composed of hydrogen in the plasma state.
Milky Way
Galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye.
It is estimated to contain 100–400 billion stars and at least that number of planets.
Supernova
A supernova ( or supernovas; abbr.
This transient astronomical event occurs during the last evolutionary stages of a massive star or when a white dwarf is triggered into runaway nuclear fusion.
Variable star
A variable star is a star whose brightness as seen from Earth (its apparent magnitude) fluctuates.