When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Light-year - Wikipedia

    en.wikipedia.org/wiki/Light-year

    A light-year, alternatively spelled light year (ly or lyr [3]), is a unit of length used to express astronomical distances and is equal to exactly 9 460 730 472 580.8 km, which is approximately 5.88 trillion mi.

  3. Solar radius - Wikipedia

    en.wikipedia.org/wiki/Solar_radius

    The result was a measured radius of 696,342 ± 65 kilometres (432,687 ± 40 miles). [4] Haberreiter, Schmutz & Kosovichev (2008) [1] determined the radius corresponding to the solar photosphere to be 695,660 ± 140 kilometres (432,263 ± 87 miles). This new value is consistent with helioseismic estimates; the same study showed that previous ...

  4. List of nearest stars - Wikipedia

    en.wikipedia.org/wiki/List_of_nearest_stars

    This number is likely much higher, due to the sheer number of stars needed to be surveyed; a star approaching the Solar System 10 million years ago, moving at a typical Sun-relative 20–200 kilometers per second, would be 600–6,000 light-years from the Sun at present day, with millions of stars closer to the Sun.

  5. Astronomical unit - Wikipedia

    en.wikipedia.org/wiki/Astronomical_unit

    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 astronomical unit, is used to measure distances beyond the ...

  6. Speed of light - Wikipedia

    en.wikipedia.org/wiki/Speed_of_Light

    A light-year is the distance light travels in one Julian year, around 9461 billion kilometres, 5879 billion miles, or 0.3066 parsecs. In round figures, a light year is nearly 10 trillion kilometres or nearly 6 trillion miles. Proxima Centauri, the closest star to Earth after the Sun, is around 4.2 light-years away. [89]

  7. Parsec - Wikipedia

    en.wikipedia.org/wiki/Parsec

    The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to 3.26 light-years or 206,265 astronomical units (AU), i.e. 30.9 trillion kilometres (19.2 trillion miles).

  8. Cosmic distance ladder - Wikipedia

    en.wikipedia.org/wiki/Cosmic_distance_ladder

    The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A direct distance measurement of an astronomical object is possible only for those objects that are "close enough" (within about a thousand parsecs ) to Earth.

  9. Milky Way - Wikipedia

    en.wikipedia.org/wiki/Milky_Way

    At this speed, it takes around 1,400 years for the Solar System to travel a distance of 1 light-year, or 8 days to travel 1 AU (astronomical unit). [113] The Solar System is headed in the direction of the zodiacal constellation Scorpius , which follows the ecliptic.