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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

    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. [citation needed] As they emerged, the Dark Ages gradually ended. Because this process was gradual, the Dark Ages only ended ...

  4. History of astronomy - Wikipedia

    en.wikipedia.org/wiki/History_of_astronomy

    The Northern Hemisphere page from Johann Bayer's 1661 edition of Uranometria - the first atlas to have star charts covering the entire celestial sphere Southern Hemisphere. The history of astronomy focuses on the contributions civilizations have made to further their understanding of the universe beyond earth's atmosphere. [1]

  5. Timeline of Solar System astronomy - Wikipedia

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

    Gersonides appears to be among the few astronomers before modern times, along Aristarcus, to have surmized that the fixed stars are much further away than the planets. While all other astronomers put the fixed stars on a rotating sphere just beyond the outer planets, Gersonides estimated the distance to the fixed stars to be no less than ...

  6. 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

  7. Timeline of the universe - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_the_early_universe

    600 million years: HE 1523-0901, the oldest star found producing neutron capture elements forms, marking a new point in ability to detect stars with a telescope. [6] 630 million years (z = 8.2): GRB 090423, the oldest gamma-ray burst recorded suggests that supernovas may have happened very early on in the evolution of the Universe [7]

  8. Star - Wikipedia

    en.wikipedia.org/wiki/Star

    The most prominent stars have been categorised into constellations and asterisms, and many of the brightest stars have proper names. Astronomers have assembled star catalogues that identify the known stars and provide standardized stellar designations. The observable universe contains an estimated 10 22 to 10 24 stars.

  9. Pillars of Creation - Wikipedia

    en.wikipedia.org/wiki/Pillars_of_Creation

    This video clip shows a visualization of the three-dimensional structure of the Pillars of Creation. Closer view of one pillar. Pillars of Creation is a photograph taken by the Hubble Space Telescope of elephant trunks of interstellar gas and dust in the Eagle Nebula, in the Serpens constellation, some 6,500–7,000 light-years (2,000–2,100 pc; 61–66 Em) from Earth. [1]