Extragalactic Distance Scale
| Method | Uncertainty for Single Galaxy (mag) | Distance to Virgo Cluster (Mpc) | Range (Mpc) |
|---|---|---|---|
| Classical Cepheids | 0.16 | 15 - 25 | 29 |
| Novae | 0.4 | 21.1 ± 3.9 | 20 |
| Planetary Nebula Luminosity Function | 0.3 | 15.4 ± 1.1 | 50 |
| Globular Cluster Luminosity Function | 0.4 | 18.8 ± 3.8 | 50 |
| Surface Brightness Fluctuations | 0.3 | 15.9 ± 0.9 | 50 |
| D - σ relation | 0.5 | 16.8 ± 2.4 | > 100 |
| Type Ia Supernovae | 0.10 | 19.4 ± 5.0 | > 1000 |
The extragalactic distance scale is a series of techniques used today by astronomers to determine the distance of cosmological bodies beyond our own galaxy, which are not easily obtained with traditional methods. Some procedures utilize properties of these objects, such as stars, globular clusters, nebulae, and galaxies as a whole. Other methods are based more on the statistics and probabilities of things such as entire galaxy clusters.
Read more about this topic: Cosmic Distance Ladder
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—Henry David Thoreau (1817–1862)