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  2. Distance modulus - Wikipedia

    en.wikipedia.org/wiki/Distance_modulus

    The distance modulus is a way of expressing distances that is often used in astronomy. It describes distances on a logarithmic scale based on the astronomical magnitude system . Definition

  3. 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.

  4. Magnitude (astronomy) - Wikipedia

    en.wikipedia.org/wiki/Magnitude_(astronomy)

    In astronomy, magnitude is a ... This is known as the distance modulus, where d is the distance to the star measured in parsecs, m is the apparent magnitude, ...

  5. Spectroscopic parallax - Wikipedia

    en.wikipedia.org/wiki/Spectroscopic_parallax

    Knowing the apparent magnitude (m) and absolute magnitude (M) of the star, one can calculate the distance (d, in parsecs) of the star using = ⁡ (/) (see distance modulus). The true distance to the star may be different than the one calculated due to interstellar extinction. [3] The method ultimately derives from the spectroscopic studies of ...

  6. Luminosity distance - Wikipedia

    en.wikipedia.org/wiki/Luminosity_distance

    Luminosity distance D L is defined in terms of the relationship between the absolute magnitude M and apparent magnitude m of an astronomical object. = ⁡ which gives: = + where D L is measured in parsecs.

  7. Comoving and proper distances - Wikipedia

    en.wikipedia.org/wiki/Comoving_and_proper_distances

    In standard cosmology, comoving distance and proper distance (or physical distance) are two closely related distance measures used by cosmologists to define distances between objects. Comoving distance factors out the expansion of the universe , giving a distance that does not change in time except due to local factors, such as the motion of a ...

  8. Distance measure - Wikipedia

    en.wikipedia.org/wiki/Distance_measure

    Distance measures are used in physical cosmology to give a natural notion of the distance between two objects or events in the universe.They are often used to tie some observable quantity (such as the luminosity of a distant quasar, the redshift of a distant galaxy, or the angular size of the acoustic peaks in the cosmic microwave background (CMB) power spectrum) to another quantity that is ...

  9. Absolute magnitude - Wikipedia

    en.wikipedia.org/wiki/Absolute_magnitude

    For objects within the immediate neighborhood of the Sun, the absolute magnitude M and apparent magnitude m from any distance d (in parsecs, with 1 pc = 3.2616 light-years) are related by = = (), where F is the radiant flux measured at distance d (in parsecs), F 10 the radiant flux measured at distance 10 pc.