Once you have worked through all of the previous steps you will be ready to plot your Hubble diagram. From this deduction came the suggestion that all the currently observed matter and energy in the universe were initially condensed in a very small and infinitely hot mass.
There are 60 arcseconds in 1 arcminute and the larger a globular cluster appears to be in the sky, the more arcminutes across it is.
Since they are intrinsically brighter than any other standard candle, they offer the opportunity for an accurate measurement of the Universe's overall expansion by looking out the farthest. What is the minimum age of the oldest cluster?
Hubble Space Telescope has taken this decades-old debate out of gridlock and on toward a solution.
We can measure comparing an observed wavelength to a rest wavelength. The situation is like the case of a road map with no scale printed on it.
One of the primary goals is to find Cepheids in more distant galaxies, opening the way to pin down an accurate value for the Hubble Constant. The models are less reliable for very low-mass stars that contain complex molecules in their outer atmospheres and for higher-mass stars, whose cores are altered by convection.
Moreover, the velocities of recession increase in proportion with distance, a discovery that has been confirmed by numerous and repeated measurements since Hubble's time. More massive stars burn faster than their lower-mass siblings.