The first inkling of any relationship between their properties was deduced by Henrietta Leavitt, who found that there was a relationship between light intensity and the period of variation.
Harlow Sharpley established a more systemic relationship between two of their properties, while Walter Baade divided them into two populations. The first inkling of any relationship between their properties was deduced by Henrietta Leavitt, who found that there was a relationship between light intensity and the period of variation. For 10 points--name these yellow and orange supergiants that can be used to determine astronomical distances.
Harlow Sharpley established a more systemic relationship between two of their properties, while Walter Baade divided them into two populations.
{Cepheid} variables