I have over 70 refereed publications based on data obtained with the Hubble Space Telescope, and have been a member of three science teams responsible for instruments on the telescope, including the Wide Field Planetary Camera 2, which restored Hubble's vision in 1993. Below are a few of the things that I have worked on over the years.

The Eagle Nebula

This Hubble Space Telescope image of the Eagle Nebula -- a region of star formation located in the constellation Serpens -- was first released in 1995, at about the time that people were beginning to understand that the Hubble Space Telescope was truly fixed and doing the science that it was meant to do.

A combination of timing, compelling science story, and striking aesthetics made this one of the most famous astrophotographs in history. Quoting from the original press release:

Eerie, dramatic pictures from NASA's Hubble Space Telescope show newborn stars emerging from "eggs" — not the barnyard variety — but rather dense, compact pockets of interstellar gas called evaporating gaseous globules (EGGs). Hubble found the "EGGs," appropriately enough, in the Eagle nebula, a nearby star-forming region 6,500 light- years away in the constellation Serpens.

"For a long time astronomers have speculated about what processes control the sizes of stars — about why stars are the sizes that they are," said Jeff Hester of Arizona State University, Tempe, AZ. "Now in M16 we seem to be watching at least one such process at work right in front of our eyes."

See the original press release or download a full sized version of the image.

The image was one of five images selected for a series of stamps issued on the 10th anniversary of the launch of the Hubble Space Telescope:

The Trifid Nebula

Like the Eagle Nebula, the Trifid Nebula is a region in which intense radiation from a nearby hot, massive, luminous star is triggering the formation of a new generation of low-mass "Sun-like" stars. This Hubble Space Telescope image is a continuation of the work begun with the Eagle Nebula, and is also the picture that graces of the cover of 21st Century Astronomy, which in some ways I like to think of more as a piece of nonfiction for the informed layman than as a textbook. (This is a hint to suggest that a serious reader might enjoy the book!)

The Crab Nebula

The Crab Nebula is the remnant of the explosion of a massive star -- a supernova -- witnessed by Chinese astronomers on July 4, 1054 AD.

At the heart of the Crab Nebula is the Crab Pulsar, a collapsed neutron star which has a mass greater than that of the Sun, but which could fit within the city limits of Phoenix. The Crab Pulsar has a magnetic field over a trillion times that of Earth, and is spinning 30 times a second. This creates extreme conditions in which matter and antimatter are formed from pure energy, then flung out into space at close to the speed of light. As relativistic electrons and positrons spin around magnetic fields, they give off an eerie glow that can be seen in X-rays, visible light, and radio emission. The image at left is a composite showing X-ray emission in blue, visible light in green, and radio emission in red.


The Hubble Space Telescope and the Chandra X-ray Observatory were used to make movies of the motion of this material as it streams out into space. Full resolution versions of the movies are available.


Images of the Crab Synchrotron filaments show the material that was blasted into space by the explosion itself. This expanding cloud of debris carries with it the chemical legacy of the material formed in star. The atoms of which our bodies are made were formed in such stars that lived and died long before our Sun and Solar System formed 4.5 billion years ago.