In a paper published today in the Astrophysical Journal Letters, available online here (subscription required for full text), astronomers announced that they have estimated the star formation rate based upon data from the Spitzer Space Telescope. The star formation rate is a number that relates to you the number of stars that form in the galaxy every year. The estimate that these astronomers conclude is that between 0.68 and 1.45 solar mass equivalent stars are formed every year in the galaxy. This number assists astronomers in many sub-fields from those who study the evolution of stars to those who ponder the existence of extraterrestrial intelligence. It is a value that is used in the famed Drake equation.
In a paper to appear in the Proceedings of the Astronomical Society of the Pacific, available online now here, astronomers review the state of the science of galactic scale star formation out of the material which constitutes the interstellar medium (ISM). Summarizing the results of some 20 years of research, the authors note that “evidence has been increasingly accumulating that there is a tight relation between the star formation rate surface density and the gas surface density on global (disk–averaged) scales in nearby galaxies.” After reviewing the latest results from a look at many galaxies in many different portions of the electromagnetic spectrum, the authors take a look at the future of this science, which not only effects stellar and galactic evolution studies, but even the astrobiologist’s Drake equation.
In a paper to be published in a future issue of the Astrophysical Journal, available online now here, astronomers have utilized data from the GALEX spacecraft to determine the star formation rate within a region of the Andromeda Galaxy, also known as M31. The star formation rate is a figure not only of interest to astronomers studying the formation of stars in galaxies and what is called the evolution of galaxies over time, but even to astrobiologists who use the figure within the famed Drake Equation. These astronomers conclude that for the past 400 million years, between 0.6 and 0.7 solar masses equivalent of stars formed each year.