enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Local standard of rest - Wikipedia

    en.wikipedia.org/wiki/Local_standard_of_rest

    The Sun follows the solar circle (eccentricity e < 0.1) at a speed of about 255 km/s in a clockwise direction when viewed from the galactic north pole at a radius of ≈ 8.34 kpc [4] about the center of the galaxy near Sgr A*, and has only a slight motion, towards the solar apex, relative to the LSR. [5] [6]

  3. Speed of light - Wikipedia

    en.wikipedia.org/wiki/Speed_of_Light

    It proposed a new, but completely equivalent, wording of the metre's definition: "The metre, symbol m, is the unit of length; its magnitude is set by fixing the numerical value of the speed of light in vacuum to be equal to exactly 299 792 458 when it is expressed in the SI unit m s −1."

  4. Peculiar velocity - Wikipedia

    en.wikipedia.org/wiki/Peculiar_velocity

    In galactic astronomy, peculiar motion refers to the motion of an object (usually a star) relative to a Galactic rest frame. Local objects are commonly examined as to their vectors of position angle and radial velocity. These can be combined through vector addition to state the object's motion relative to the Sun.

  5. Oort constants - Wikipedia

    en.wikipedia.org/wiki/Oort_constants

    Figure 1: Geometry of the Oort constants derivation, with a field star close to the Sun in the midplane of the Galaxy. Consider a star in the midplane of the Galactic disk with Galactic longitude at a distance from the Sun. Assume that both the star and the Sun have circular orbits around the center of the Galaxy at radii of and from the Galactic Center and rotational velocities of and ...

  6. Proper motion - Wikipedia

    en.wikipedia.org/wiki/Proper_motion

    This motion is caused by the movement of the stars relative to the Sun and Solar System. The Sun travels in a nearly circular orbit (the solar circle ) about the center of the galaxy at a speed of about 220 km/s at a radius of 8,000 parsecs (26,000 ly) from Sagittarius A* [ 5 ] [ 6 ] which can be taken as the rate of rotation of the Milky Way ...

  7. Galactic year - Wikipedia

    en.wikipedia.org/wiki/Galactic_year

    The Solar System is traveling at an average speed of 230 km/s (828,000 km/h) or 143 mi/s (514,000 mph) within its trajectory around the Galactic Center, [3] a speed at which an object could circumnavigate the Earth's equator in 2 minutes and 54 seconds; that speed corresponds to approximately 1/1300 of the speed of light.

  8. Cosmic distance ladder - Wikipedia

    en.wikipedia.org/wiki/Cosmic_distance_ladder

    The Earth's orbit is known with an absolute precision of a few meters and a relative precision of a few parts in 100 billion (1 × 10 −11). Historically, observations of Venus transits were crucial in determining the AU; in the first half of the 20th century, observations of asteroids were also important.

  9. The Scale of the Universe - Wikipedia

    en.wikipedia.org/wiki/The_Scale_of_the_Universe

    10 −8 meters — Porcine circovirus — 1.7 × 10 −8 meters Transistor gate — 2.5 × 10 −8 meters Hepatitis B virus — 4.2 × 10 −8 meters Ultraviolet light wavelength 5 × 10 −8 meters 6 × 10 −8 meters Human immunodeficiency virus (HIV) 9 × 10 −8 meters 9 × 10 −8 meters Depth of a pit in a CD: 1.2 × 10 −7 meters