1. A star with 15 < g < 18

  2. A very bright star with g < 12

  3. A face-on spiral galaxy

  4. An edge-on spiral galaxy

  5. An elliptical galaxy

  6. An irregular galaxy

  7. A galaxy with a spectrum

  8. An asteroid that shows up as a blue-yellow dot

  9. A "Ghost"

  10. A meteor

  11. A very faint star with g > 21

  12. A very red star with r-z > 1.5

  13. A star cluster

  14. A galaxy cluster

  15. A quasar (hint: look for a red star, then look at its spectrum in the Object Explorer)
  16. A pair of interacting galaxies

  17. A very blue galaxy with g-r < 0

  18. The object with the largest i-z value (the reddest object) you can find!