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
Famous quotes containing the words distance and/or scale:
“The rage for road building is beneficent for America, where vast distance is so main a consideration in our domestic politics and trade, inasmuch as the great political promise of the invention is to hold the Union staunch, whose days already seem numbered by the mere inconvenience of transporting representatives, judges and officers across such tedious distances of land and water.”
—Ralph Waldo Emerson (18031882)
“Tis very certain that each man carries in his eye the exact indication of his rank in the immense scale of men, and we are always learning to read it. A complete man should need no auxiliaries to his personal presence.”
—Ralph Waldo Emerson (18031882)