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  2. List of nearest stars - Wikipedia

    en.wikipedia.org/wiki/List_of_nearest_stars

    The star, whose mass is roughly half that of the Sun, is currently 62 light-years from the Solar System. It was first noticed in 1999 using data from the Hipparcos satellite, and was estimated to pass less than 1.3 light-years (0.40 pc) from the Sun in 1.4 million years. [ 73 ]

  3. Light-year - Wikipedia

    en.wikipedia.org/wiki/Light-year

    The light-year is most often used when expressing distances to stars and other distances on a galactic scale, especially in non-specialist contexts and popular science publications. [4] The unit most commonly used in professional astronomy is the parsec (symbol: pc, about 3.26 light-years).

  4. List of the most distant astronomical objects - Wikipedia

    en.wikipedia.org/wiki/List_of_the_most_distant...

    For comparisons with the light travel distance of the astronomical objects listed below, the age of the universe since the Big Bang is currently estimated as 13.787±0.020 Gyr. [1] Distances to remote objects, other than those in nearby galaxies, are nearly always inferred by measuring the cosmological redshift of their light. By their nature ...

  5. Cosmic distance ladder - Wikipedia

    en.wikipedia.org/wiki/Cosmic_distance_ladder

    The amount of shift is quite small, even for the nearest stars, measuring 1 arcsecond for an object at 1 parsec's distance (3.26 light-years), and thereafter decreasing in angular amount as the distance increases. Astronomers usually express distances in units of parsecs (parallax arcseconds); light-years are used in popular media.

  6. Astronomical unit - Wikipedia

    en.wikipedia.org/wiki/Astronomical_unit

    Light-day: 173 – Distance light travels in one day – Light-year: 63,241 – Distance light travels in one Julian year (365.25 days) – Oort cloud: 75,000: ± 25,000: Distance of the outer limit of Oort cloud from the Sun (estimated, corresponds to 1.2 light-years) – Parsec: 206,265 – One parsec. The parsec is defined in terms of the ...

  7. Andromeda Galaxy - Wikipedia

    en.wikipedia.org/wiki/Andromeda_Galaxy

    Andromeda has a D 25 isophotal diameter of about 46.56 kiloparsecs (152,000 light-years) [8] and is approximately 765 kpc (2.5 million light-years) from Earth. The galaxy's name stems from the area of Earth's sky in which it appears, the constellation of Andromeda , which itself is named after the princess who was the wife of Perseus in Greek ...

  8. Stellar parallax - Wikipedia

    en.wikipedia.org/wiki/Stellar_parallax

    The parsec (3.26 light-years) is defined as the distance for which the annual parallax is 1 arcsecond. Annual parallax is normally measured by observing the position of a star at different times of the year as Earth moves through its orbit. The angles involved in these calculations are very small and thus difficult to measure.

  9. Globular cluster - Wikipedia

    en.wikipedia.org/wiki/Globular_cluster

    In comparison, the stellar density around the Sun is roughly 0.1 stars/pc 3. [53] The typical distance between stars in a globular cluster is about one light year, [54] but at its core the separation between stars averages about a third of a light year – thirteen times closer than the Sun is to its nearest neighbor, Proxima Centauri. [55]