From the Hubble Space Telescope
NGC 1999 is a reflection nebula which shines only because light from an embedded source illuminates its dust; the nebula does not emit any visible light of its own. It illuminated by a bright, recently formed star V380 Orionis, visible just to the left of center. Its white color is due to its 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. 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. Herbig-Haro objects are now known to be jets of gas ejected from very young stars.
This 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. New stars may be forming inside Bok globules, through the contraction of the dust and molecular gas under their own gravity.
Image Title: A Reflection Nebula in Orion
based on press release for PHOTO NO.: STScI-PRC00-10
Image Credit: NASA and The Hubble Heritage Team (STScI)
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Last Modified On: Tuesday, December 19, 2000