| The dust and debris disk surrounding the star AU Microscopii, as imaged by the Hubble Space Telescope.The lines indicate the polarization of starlight reflected from the disk, which reveals the porosity or fluffiness of the dust grains. The disk is about 120 astronomical units (AU) across, where one AU is equivalent to the distance between the Earth and sun, or 93 million miles. (Credit: NASA, ESA and James Graham/UC Berkeley) |
