The nebular hypothesis for the origin of our Solar System has been bolstered
by a variety of recent observations that look very much like star and planetary
systems in various stages of formation.
New Solar Systems
Recent Hubble Space Telescope observations shed considerable light on the birth of stars and associated planetary systems. The following image shows regions in the Orion Nebula where solar systems may be forming.
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| Regions in the Orion Nebula where solar systems appear to be forming |
The Orion Nebula is approximately 1500 light
years from Earth. It is visible to the naked eye as the middle "star"
in the sword of the constellation Orion. These images were taken with
the Wide
Field Planetary Camera 2 of the Hubble Space Telescope (C.R. O'Dell,
Rice University). Details of the images show several protoplanetary disks
( proplyds ), including
a single dark disk surrounding a central star. The lower left inset figure
shows a drawing giving the approximate scale of our Solar System relative
to the proplyd.
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Here is a HST
movie (650 kB MPEG) illustrating these protoplanetary disks in the
Orion Nebula, here is a further discussion
of these planetary systems now forming in Orion.
More Star-Forming Regions
Many other star-forming regions are known. In addition to the Eagle Nebula discussed below, here are images and discussion of- Star-forming regions in the Trapezium (the central region of the Orion Nebula).
- Star formation in the Lagoon Nebula, with possible evidence for tornadoes 1/2 light year in length.
- Star-forming region in the nebula NGC 604 (in the galaxy M33).
Star Formation in the Eagle Nebula
The following images show examples in the Eagle Nebula of regions where stars (and possibly solar systems) appear to be forming.
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| Star-Birth Clouds in M16 (Eagle Nebula). J. Hester and P. Scowon (Arizona St. Univ.), November 2, 1995. Taken with NASA Hubble Space Telescope, WFPC2 | |
The scale of the image on the left is about 1 light year. The blowup on
the right shows finger-like structures that are thought to be regions
in which new stars are being formed. The tips of these finger-like objects
are about the size of our Solar System! Here is a spectacular
movie (780 kB) of these star-forming regions in the Eagle Nebula made
with the Hubble Space Telescope. This movie is about as close as you are
ever going to get to the bridge of the Starship Enterprise!
Planets Around other Stars
In recent years rather conclusive evidence has accumulated for planets orbiting other stars. This evidence comes from the gravitational perturbations exerted on the star by the unseen companion planet that can be exposed by very accurate measurement of the radial velocity of the star (see the related discussion of detecting unseen companions in binary star systems). These measurements require that variations in the radial velocity of order 10 meters per second be detected relative to a total radial velocity typically of order 10-100 kilometers per second.
Information supplied by: http://csep10.phys.utk.edu