ALT A bright ball at the center of the image represents a white dwarf star that glows in pale yellow. Surrounding the star is a disk of material. The disk starts a little distance away from the star and is tilted down to the right. The disk glows in orange closest to the star and fades to grays out to its edges. In the lower left is a blotchy cloud of white gas and dust with a trail leading to the edge of the material disk. The image is watermarked “Artist’s concept” and “Credit: NASA’s Goddard Space Flight Center/Scott Wiessinger.”

ALT Hot stars burn brightly in this ultraviolet image of the Andromeda galaxy from NASA's Galaxy Evolution Explorer. Blue-white bands making up the galaxy's striking rings are neighborhoods that harbor hot, young, massive stars. Dark blue-gray lanes of cooler dust show up starkly against these bright rings, tracing regions where stars currently form in dense cloudy cocoons. Eventually, these dusty lanes will blow away when the forming stars ignite nuclear fusion in their core. Meanwhile, the central orange-white ball reveals a congregation of cooler, old stars that formed long ago. This image is watermarked “Credit: NASA/JPL-Caltech”