The Orion Proplyds
were first discovered by the Hubble Space Telescope. Astronomers expected the
Orion nebula to be a host for lots of star formation, and were amazed to see
that Hubble could resolve individual young stars. The Proplyds are young stars
surrounded by a gaseous circumstellar disk . In the image of the Orion Nebula
above, the proplyds are enlarged so you can see the bright central star
surrounded by a dark oval shaped ring. The disks appear dark because they are
absorbing the light emitted by the nebula, and re-emitting it in the infrared,
a wavelength of light that does not appear bright in these images. Portions of
these disks will eventually fall onto the star, and the rest will either form
planets, or be dispersed back into the nebula. Astronomers are using these, and
other images of young stars, to learn about how stars form and how planetary
systems evolve.
Image Credit:
NASA, ESA, M.
Robberto (Space Telescope Science Institute/ESA), the Hubble Space Telescope
Orion Treasury Project Team and L. Ricci (ESO)
