PHOTO NO.: STScI-PRC00-10
Just weeks after NASA astronauts repaired the Hubble Space
Telescope in December 1999, the Hubble Heritage Project snapped
this picture of NGC 1999, a nebula in the constellation Orion.
The Heritage astronomers, in collaboration with scientists in
Texas and Ireland, used Hubble’s Wide Field Planetary Camera 2
(WFPC2) to obtain the color image.
NGC 1999 is an example of a reflection nebula. Like fog around
a street lamp, a reflection nebula shines only because the light from an embedded source illuminates
its dust; the nebula does not emit any visible light of its own. NGC 1999 lies close to the
famous Orion Nebula, about 1,500 light-years from Earth, in a
region of our Milky Way galaxy where new stars are being formed
actively. The nebula is famous in astronomical history because
the first Herbig-Haro object was discovered immediately adjacent to it (it lies just outside the new
Hubble image). Herbig-Haro
objects are now known to be jets of gas ejected from very young
stars.
The NGC 1999 nebula is illuminated by a bright, recently formed
star, visible in the Hubble photo just to the left of
center. This star is cataloged as V380 Orionis, and its white
color is due to its high surface temperature of about 10,000 degrees Celsius (nearly twice that of
our own Sun). Its mass is estimated to be 3.5 times that of the Sun. The star is so young that it is
still surrounded by a cloud of material left over from its formation, here seen as the NGC 1999
reflection nebula.
The WFPC2 image of NGC 1999 shows a remarkable jet-black cloud
near its center, resembling a letter T tilted on its side,
located just to the right and lower right of the bright
star. This dark cloud is an example of a “Bok globule,” named after the late University of Arizona
astronomer Bart Bok. The
globule is a cold cloud of gas, molecules, and cosmic dust, which is so dense it blocks all of the light
behind it. In the
Hubble image, the globule is seen silhouetted against the
reflection nebula illuminated by V380 Orionis. Astronomers
believe that new stars may be forming inside Bok globules,
through the contraction of the dust and molecular gas under their own gravity.
NGC 1999 was discovered some two centuries ago by Sir William
Herschel and his sister Caroline, and was cataloged later in the 19th century as object 1999 in the
New General Catalogue.
These data were collected in January 2000 by the Hubble Heritage Team with the collaboration of
star-formation experts C. Robert
O’Dell (Rice University), Thomas P. Ray (Dublin Institute for
Advanced Study), and David Corcoran (University of Limerick).
Image Credit: NASA and the Hubble Heritage Team (STScI)
NOTE TO EDITORS — For additional information, please contact:
Professor C. R. O’Dell, Rice University, MS 108, PO Box 1892,
Houston, Texas 77251-1892, (phone) 713-348-3633, (fax) 713-348-5143, (e-mail) cro@rice.edu or
Professor T.P. Ray, School Of Cosmic Physics, Dublin Institute for Advanced Studies, 5 Merrion
Square, Dublin 2, Ireland, (phone)
+353 1 6621333, (fax) +353 1 6621477, (e-mail) tr@cp.dias.ie or
Keith Noll, Space Telescope Science Institute, 3700 San Martin
Drive, Baltimore, Md. 21218, (e-mail) noll@stsci.edu.
Image files are available on the Internet at:
http://oposite.stsci.edu/pubinfo/pr/2000/10 or via links in
http://oposite.stsci.edu/pubinfo/latest.html and
http://oposite.stsci.edu/pubinfo/pictures.html
Higher resolution digital versions (300 dpi JPEG and TIFF) are
available at:
http://oposite.stsci.edu/pubinfo/pr/2000/10/pr-photos.html
