Press Release

A Bow Shock Near A Young Star

By SpaceRef Editor
March 6, 2002
Filed under , ,

NASA’s Hubble Space Telescope continues to reveal various stunning
and intricate treasures that reside within the nearby, intense
star-forming region known as the Great Nebula in Orion. One such
jewel is the bow shock around the very young star, LL Ori, featured
in this Hubble Heritage image.

Named for the crescent-shaped wave made by a ship as it moves
through water, a bow shock can be created in space when two streams
of gas collide. LL Ori emits a vigorous solar wind, a stream of
charged particles moving rapidly outward from the star. Our own Sun
has a less energetic version of this wind that is responsible for
auroral displays on the Earth.

The material in the fast wind from LL Ori collides with slow-moving
gas evaporating away from the center of the Orion Nebula, which is
located to the lower right in this Heritage image. The surface where
the two winds collide is the crescent-shaped bow shock seen in the

Unlike a water wave made by a ship, this interstellar bow shock is
a three-dimensional structure. The filamentary emission has a very
distinct boundary on the side facing away from LL Ori, but is diffuse
on the side closest to the star, a characteristic common to many bow

A second, fainter bow shock can be seen around a star near the upper
right-hand corner of the Heritage image. Astronomers have identified
numerous shock fronts in this complex star-forming region and are
using this data to understand the many complex phenomena associated
with the birth of stars.

This image was taken in February 1995 as part of the Hubble Orion
Nebula mosaic. A close visitor in our Milky Way galaxy, the nebula
is only 1,500 light-years from Earth. The filters used in this color
composite represent oxygen, nitrogen, and hydrogen emissions.

Image Credit: NASA and the Hubble Heritage Team (STScI/AURA)
Acknowledgment: C. R. O’Dell (Vanderbilt University)

NOTE TO EDITORS: For additional information, please contact
Dr. Keith Noll, Hubble Heritage Team, Space Telescope Science
Institute, 3700 San Martin Drive, Baltimore, MD 21218, (phone)
410-338-1828, (fax) 410-338-4579, (e-mail)

Electronic images and additional information are available at: and and via links in

SpaceRef staff editor.