Astronomy Picture of the Day . ... Accretion Disk Binary System . ... Our Sun is unusual in that it is alone - most stars occur in multiple or binary systems. ... Irregular Galaxy Sextans A . ... But small irregular galaxies form stars too, like this lovely, gumdrop-shaped galaxy, Sextans A. Hot Gas In Hydra A . ... This false-color radio wavelength picture of an expanding stellar debris cloud is the product of one of the largest radio astronomy experiments ever. ...