In two sentences: the Doppler shift explanation is a linear approximation to the "stretched light" explanation. This meant that the further from Earth a Star was, the faster it was receding.
The red shift of the spectral lines is commonly expressed in terms of the z-parameter, which is the fractional shift in the spectral wavelength. In this animation, the galaxy on the left was formed a long time ago, while the galaxy on the right was formed more recently. It helps astronomers define the expansion of the universe. Subsequent work has confirmed the general features of Hubble's law, but one specific part—Hubble's constant—has been drastically corrected.

If you graph this relation, the slope of the line is the Hubble constant, or a measure of the expansion rate of the universe . Originally a concept piece for an astronomy magazine to illustrate a article on magnetars, this piece was detailed out further and became my version of a star undergoing dramatic changes and beginning to have a profound effect on it’s planetary system. In a word: yes. Are the light waves "stretched" as the universe expands, or is the light Doppler-shifted because distant galaxies are moving away from us? The farther away a galaxy is, the faster it moves away from us. This correlation is now known as Hubble's Law . Hubble made the startling discovery that the farther away a galaxy is, the greater its redshift appears to us. Cosmological Redshift: the wavelength of the emitted radiation is lengthened due to the expansion of the Universe. The simplest explanation for Hubble’s observation, and the one that Hubble himself offered, was that the entire universe is expanding, just as Einstein's equations predicted it should.
The Hubble distance is given by An estimate of the redshift can be obtained from comparing the data from the ultraviolet, the visual, the near infrared, and the infrared. This is less accurate than spectroscopy, but does give a rough indication of the redshift and thus the distance to the object. Hubble also noticed that the further away the Cepheid Variable Star was from Earth, the Greater the Redshift of the Star. For example, a red shift of 0.05 means that all wavelengths are increased by 5% because of the recessional velocity. Red Shift. Edwin Powell Hubble (November 20, 1889 - September 28, 1953) was an American astronomer, noted for his discovery of galaxies beyond the Milky Way and the cosmological redshift.

The Hubble relation is a (locally) linear correlation between the redshift of a galaxy and its distance from the Milky Way. Hubble Parameter and Red Shifts The Hubble Law states that the distance to a given galaxy is proportional to the recessional velocity as measured by the Doppler red shift. Thus the velocity of any given galaxy is measured by its red shift. This red shift was interpreted as a sign that the galaxies are moving away from us. What causes the Hubble Redshift? In fact, Hubble found that if he plotted a graph of Distance against Recessional Velocity, the … Hubble's diagram showed that a galaxy's redshift increased linearly with its distance from Earth. Hubble and his colleagues compared the distance estimates to galaxies with their red shifts .