Explanation:
L1551-IRS5, which is about 450 light years away from the Earth, is believed to be a binary system consisting of two protostars. (A protostar is a cloud of gas which is collapsing prior to starting nuclear fusion at its core.) This picture shows two parallel jets (green) being emitted from a nebula (white, located slightly left of center), within which the protostars are located. Observations with the Hubble Space Telescope had previously revealed the two jets. However, the high resolution of the Subaru Telescope has allowed them to be separated from the ground for the first time. Analysis has revealed that the jets emit strongly in light produced by ionized iron. The jets are thought to be produced separately by each of the protostars, and extend for about 1500 AU. (1 AU, or Astronomical Unit, is the distance between the Earth and the Sun: 93 million miles or 150 million km.) The white nebula is called an ``infrared reflectance nebula'', and it emits by reflecting strong infrared light from the protostars. In addition, a strong wind from the protostars blows ambient material away and evacuates a cavity around the jets, and the edge of this cavity also reflects light from the protostars. Jets are thought to be produced on both sides of a protostar; in the case of L1551-IRS5, we can only see the jets pointed towards us because the oppositely-directed jets are hidden by intervening, dusty material.

August 24, 1999