NASA's Spitzer Space Telescope captured this infrared image of a giant halo of very fine dust around the young star HR 8799, located 129 light-years away in the constellation Pegasus. The brightest parts of this dust cloud (yellow-white) likely come from the outer cold disk similar to our own Kuiper belt (beyond Neptune's orbit). The huge extended dust halo is seen as orange-red.
Astronomers think that the three large planets known to orbit the star are disturbing small comet-like bodies, causing them to collide and kick up dust. The extended dust halo has a diameter of about 2,000 astronomical units, or 2,000 times the distance between Earth and the sun. For reference, the size of Pluto's orbit is tiny by comparison, with a diameter of about 80 astronomical units.
This image was captured by Spitzer's multiband imaging photometer at an infrared wavelength of 70 microns in Jan. 2009.
Astronomers think that the three large planets known to orbit the star are disturbing small comet-like bodies, causing them to collide and kick up dust. The extended dust halo has a diameter of about 2,000 astronomical units, or 2,000 times the distance between Earth and the sun. For reference, the size of Pluto's orbit is tiny by comparison, with a diameter of about 80 astronomical units.
This image was captured by Spitzer's multiband imaging photometer at an infrared wavelength of 70 microns in Jan. 2009.
