| Astrophysics (Index) | About |
In astrophysics, the term chemical tagging is used for the technique of determining the origin of stars from their abundances, based on the idea that stars share a good bit of their chemical makeup with that of the molecular cloud where they formed so the spectra of the stars are effectively the star's tag, revealing its origin. The technique has the potential to associate stars that are far apart as being formed near each other through their spectral energy distributions (SEDs), which offers a tool to galactic archaeology (determining the history of the galaxy). There is also the potential to determine the evolution of clouds, using stars from related clouds to determine when metals appeared in various portions of the interstellar medium (ISM) as time passed.
Techniques along this general idea have been used to identify stars that belong to stellar associations, and alpha enhancement is thought to reveal some history, but drawing the above-listed particular conclusions has challenges: it remains difficult to establish that a pair of stars has identical abundances if they are of different spectral types.
The term chemical tagging is used in biology as well, for an unrelated method of tracing proteins.