Remember the scene in Blade Runner in which Deckard successively zooms and enhances a digitized photograph found at a crime scene? In 1982, it seemed to epitomize the fashionably sleek high tech, and it left a strong impression on me.
In this post from last February, I wrote about the protostellar disks in Orion that were imaged by the Hubble Space Telescope in the mid-1990s. One of these disks has achieved nearly iconic status (at least among those of us who give talks on planet formation). The following image shows it viewed edge-on and in silhouette against a background of glowing nebular gas. Only a faint smudge of red hints at the central star embedded within the disk.
This disk is roughly 17 times larger than the orbit of Neptune. It’s also considerably larger than the orbits of 2003 UB-313 and Sedna, which I’ve integrated and placed on top of the image for comparison.
The Hubble press release that accompanies the disk image highlights a number of different protostellar disks, or “proplyds”, many of which are being strongly photoevaporated by radiation from the nearby high-mass stars of the Trapezium cluster. This region is faintly visible to the naked eye as the unresolved middle “star” of Orion’s sword:
A growing body of evidence suggests that our own solar system may well have formed in a similarly disruptive environment. Analysis of meteorites shows evidence that radioactive atoms with short half-lives (in particular, Aluminum 26) freshly ejected from a nearby supernova in the birth cluster may have been incorporated into our solar system’s protostellar disk. The scattered orbits of bodies such as Sedna also hint that the solar system may have had a close encounter with another star at an early time in its history. Close encounters only occur in a dense stellar environment.
On the Hubble press release page, there is a 22.97 MB Tif image of the entire Trapezium region. When the full image is displayed at laptop-screen resolution, it isn’t clear where the protostellar disks actually are. If, however, you slog through the full download and open the image in a program like Photoshop, then, like Deckard, you can zoom in with successively higher resolution to find the disks shown in the press release. The resolution in the 23 MB Tif image is not the full resolution provided by the actual mosaic of images, but it’s high enough to enable discovery of a lot of detail. A leisurely exploration of the image with pan and the zoom controls gives an amazing sense of the overall structure of the stellar nursery. The three-dimensionality of the cluster is easier to visualize. You can sense that the disk is suspended in empty space, in a slow, arcing free-fall through the cluster, making it somehow easier to grasp that this is an image of new worlds in the process of creation.