Astronomy and Astrophysics – Astronomy
Scientific paper
Oct 1982
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1982lastr..96..435g&link_type=abstract
L'Astronomie, vol. 96, Oct. 1982, p. 435-445. In French.
Astronomy and Astrophysics
Astronomy
Astrometry, Astronomical Coordinates, Big Bang Cosmology, Celestial Reference Systems, Hubble Constant, Distance, Galactic Rotation, Magellanic Clouds, Radio Astronomy, Stellar Parallax
Scientific paper
Techniques for establishing stellar distances and distance reference scales are reviewed. Direct measurements of distances to stars are currently possible by using trigonometric parallaxes, i.e., acquiring angular data on stars by viewing them on two occasions six months apart. Distances are then scaled on a base of 300 million km, working from displacements of no more than 1.5 arcsec. Hubble's use of a period-luminosity arrangement permitted measurements of distances between globular clusters, approximated by distances to Cepheid stars within the clusters. Various methods of determining the Hubble constant, expressing the expansion rate of the universe, are reviewed. Radioastronomical measurements provide a data base of the radial speeds of galaxies by determinations of the Doppler-Fizeau effect of shifting wavelengths. Finally, a linear relationship has been determined between the magnitude of a galaxy and its maximum rotational speed, thereby permitting the formulation of an actual means of measuring distances to other galaxies.
No associations
LandOfFree
Towards a new scale of extragalactic distances does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Towards a new scale of extragalactic distances, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Towards a new scale of extragalactic distances will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1031417