American Scientist

To the Editors:

In the excellent article "Improve Your Image" by Roger Harris (Science Observer, May-June), there was considerable discussion on the contributions of amateur astronomers and the relationship between professionals and amateurs in astronomy. Several examples were given, such as the discovery of comets and supernovae by amateur astronomers.

There is another important, and relatively new, area of astronomical research that amateurs have contributed to substantially, which was not mentioned in the article. It is the rapid observation of the fading optical afterglows from gamma-ray bursts (GRBs).

GRBs are among the most intense areas of research in high-energy astrophysics, and they represent the largest known explosions in the universe. Last year, NASA launched the Swift satellite to rapidly locate and observe GRBs and their afterglows at x-ray, ultraviolet and optical wavelengths. These afterglow observations are particularly important for the understanding of these enormous explosions that occur at cosmological distances (near the edge of the observable universe).

Amateur astronomers, due to their large numbers, their ability to respond quickly to the randomly located GRBs and the availability of highly sensitive CCD cameras, have been able to provide important, early data on the optical afterglows of GRBs in the past few years. At least one optical afterglow from a GRB was discovered by an amateur astronomer. Observations can be done with even a modest-size telescope, provided the observations are made quickly enough.

The optical counterparts of GRBs are the most distant objects that can be observed by an amateur, and they are, in fact, among the most distant objects that can be observed by even the largest telescopes in the world.

The organization that is helping amateur astronomers with their attempts to observe GRB afterglows is the American Association of Variable Star Observers (AAVSO) in Cambridge, Massachusetts (www.aavso.org).

Jerry Fishman
NASA Marshall Space Flight Center
Huntsville, Alabama