Succession of methods by which astronomers determine the distances to celestial objects
For various definitions of distance in cosmology, see Distance measures (cosmology).
This article's lead section may be too short to adequately summarize the key points. Please consider expanding the lead to provide an accessible overview of all important aspects of the article.(January 2023)
Light green boxes: Technique applicable to star-forming galaxies.
Light blue boxes: Technique applicable to population II galaxies.
Light Purple boxes: Geometric distance technique.
Light Red box: The planetary nebula luminosity function technique is applicable to all populations of the Virgo Supercluster.
Solid black lines: Well calibrated ladder step.
Dashed black lines: Uncertain calibration ladder step.
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. The techniques for determining distances to more distant objects are all based on various measured correlations between methods that work at close distances and methods that work at larger distances. Several methods rely on a standard candle, which is an astronomical object that has a known luminosity.
The ladder analogy arises because no single technique can measure distances at all ranges encountered in astronomy. Instead, one method can be used to measure nearby distances, a second can be used to measure nearby to intermediate distances, and so on. Each rung of the ladder provides information that can be used to determine the distances at the next higher rung.
and 24 Related for: Cosmic distance ladder information
The cosmicdistanceladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to...
would provide Edwin Hubble with the rung on the cosmicdistanceladder he would need to determine the distance to spiral nebula. Hubble used the 100-inch Hooker...
Cepheid variable its distance is used as part of the cosmicdistanceladder. The revised Hipparcos stellar parallax gives a distance to Polaris of about...
sides of the Sun in its orbit. These distances form the lowest rung of what is called "the cosmicdistanceladder", the first in a succession of methods...
he published in 1786. The distance to the Pleiades can be used as a key first step to calibrate the cosmicdistanceladder. As the cluster is relatively...
(for very short distances). The cosmicdistanceladder is a set of ways of measuring extremely long distances. The straight-line distance between two points...
possible to estimate distances via the cosmicdistanceladder. When the recessional velocities are plotted against these distances, a linear relationship...
to construct the cosmicdistanceladder. The relation between the angular diameter, θ, actual (physical) diameter, r, and distance, D, of an object from...
portal Big Bang Comoving and proper distances Friedmann equations Parsec Physical cosmology Cosmicdistanceladder Friedmann–Lemaître–Robertson–Walker...
as standard candles to measure (extra) galactic distances, assisting with the cosmicdistanceladder. This class is named after the prototype and brightest...
an important step on the cosmicdistanceladder. Parallax in astronomy Photometric parallax method Dynamical parallax Distance modulus Carroll, Bradley...
The cosmicdistanceladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to...
analyses agree, thereby making the cluster an important rung on the cosmicdistanceladder. The open cluster is roughly twice as distant as the Hyades and...
accepted values of 74 km/s/Mpc (cosmicdistanceladder method) or 68 km/s/Mpc (CMB method) due to errors in their distance calibrations. Yet the reason for...
Astronomical Telegrams (CBAT) has tracked novae in M31, M33, and M81. Cosmicdistanceladder Crab Nebula Guest star (astronomy) Kilonova Micronova Superluminous...
lensing, the description and evolution of cosmic structures, and the reconstruction of the cosmicdistanceladder. Since 2019, she has been engaged in disseminating...
must then be adjusted accordingly. Astronomical units of length Cosmicdistanceladder List of examples of lengths Orders of magnitude (length) Scale (analytical...
parallax of nearby stars provides a fundamental baseline in the cosmicdistanceladder that is used to measure the scale of the Universe. Parallax measurements...
Hubble constant—one based on redshifts and another based on the cosmicdistanceladder—disagree by about 10%. This difference, the Hubble tension, might...
was determined from supernovae, known as standard candles or the cosmicdistanceladder; Fermilab thought the age of the universe was around 20 billion...
proximity means the star is a useful calibrator in computing the cosmicdistanceladder. Based on parallax measurements, it is approximately 1,200 light-years...
physical parameters and distance are still poorly known. It would be a valuable step on the cosmicdistanceladder, clarifying the distance of other high luminosity...
Global Information
