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  2. Timeline of knowledge about galaxies, clusters of galaxies ...

    en.wikipedia.org/wiki/Timeline_of_knowledge...

    5th century BC – Democritus proposes that the bright band in the night sky known as the Milky Way might consist of stars. 4th century BC – Aristotle believes the Milky Way to be caused by "the ignition of the fiery exhalation of some stars which were large, numerous and close together" and that the "ignition takes place in the upper part of the atmosphere, in the region of the world which ...

  3. Chronology of the universe - Wikipedia

    en.wikipedia.org/wiki/Chronology_of_the_universe

    The first generation of stars, known as Population III stars, formed within a few hundred million years after the Big Bang. [49] These stars were the first source of visible light in the universe after recombination. Structures may have begun to emerge from around 150 million years, and early galaxies emerged from around 180 to 700 million years.

  4. Stellar evolution - Wikipedia

    en.wikipedia.org/wiki/Stellar_evolution

    Representative lifetimes of stars as a function of their masses The change in size with time of a Sun-like star Artist's depiction of the life cycle of a Sun-like star, starting as a main-sequence star at lower left then expanding through the subgiant and giant phases, until its outer envelope is expelled to form a planetary nebula at upper right Chart of stellar evolution

  5. The Five Ages of the Universe - Wikipedia

    en.wikipedia.org/wiki/The_Five_Ages_of_the_Universe

    The Stelliferous Era, is defined as, "6 < n < 14". This is the current era, in which matter is arranged in the form of stars, galaxies, and galaxy clusters, and most energy is produced in stars. Stars will be the most dominant objects of the universe in this era. Massive stars use up their fuel very rapidly, in as little as a few million years.

  6. Timeline of Solar System astronomy - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_Solar_System...

    c. 560 BCE – Anaximander is arguably the first to conceive a mechanical model of the world, although highly inaccurate: a cylindrical Earth [11] floats freely in space surrounded by three concentric wheels turning at different distances: the closest for the stars and planets, the second for the Moon and the farthest for the Sun, all conceived ...

  7. Timeline of space exploration - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_space_exploration

    This is a timeline of space exploration which includes notable achievements, first accomplishments and milestones in humanity's exploration of outer space. This timeline generally does not distinguish achievements by a specific country or private company, as it considers humanity as a whole.

  8. Real shooting stars exist, but they aren't the streaks you ...

    www.aol.com/news/real-shooting-stars-exist-arent...

    Shooting stars – such as those produced by the Leonid meteor shower depicted in this print from 1889 – are beautiful, but they have nothing to do with real stars. Adolf Vollmy/Wi.

  9. Astronomy - Wikipedia

    en.wikipedia.org/wiki/Astronomy

    The study of stars and stellar evolution is fundamental to our understanding of the Universe. The astrophysics of stars has been determined through observation and theoretical understanding; and from computer simulations of the interior. [99] Star formation occurs in dense regions of dust and gas, known as giant molecular clouds.