The Orion Nebula, M42.  Photo credit: Jason Ware

The student becomes familiar with the night sky through observations of celestial objects.

Becoming a good observer takes practice. The sketches of what you observe tonight should be of what you see, not what you think you should have seen nor what some book has pictured. This exercise offers just an inkling of what observational astronomy is all about.


Print out this page, and go outside!

Fill in the boxes, and answer the questions.

Place of observations:
Weather/sky conditions:

  1. Our moon: Luna
  2. Make a rough sketch of the Moon as seen with your naked eye, and as seen through a telescope. Label your sketches with N, S, E, and W.
    Naked EyeThrough Telescope

  3. Altitude of Polaris
  4. Using your astrolabe, hand-at-arm's-length, or degree scale on your planisphere, estimate the altitude of Polaris. Compare your value with that determined by a few other classmates.

    Altitude of Polaris:

  5. Observations of a Planet
  6. Do one of the following three observations
    Sketch Saturn, showing its rings, and any visible moons Sketch Jupiter, showing any markings and any visible moons Sketch Venus, showing its phase

  7. Observations of a Binary Star
  8. Do one of the following two observations
    Observe and sketch the double star Mizar (z Ursae Majoris). Observe and sketch the visual double star Albireo (b Cygni)

  9. Observations of Constellations
  10. Do all of the following observations
    Constellation 1 Constellation 2
    Constellation 3 Constellation 4

  11. Observations of Deep Sky Objects
  12. Do two of the following three observations
    Sketch, and describe an example of an open cluster Sketch, and describe an example of a globular cluster Sketch, and describe an example of a nebula or a galaxy


(answer those pertaining to your observations)
  1. Luna: Consider your sketches of the Moon. Does the telescope you used invert and/or reverse the image of the Moon? How can you tell?




  2. Polaris: The latitude of Seattle/Tacoma is about 48 degrees. Compare your value for the altitude of Polaris with this latitude. Within your observational errors for the altitude of Polaris, are these values the same? Should they be? Comment.




  3. Binary Star:
    1. Immediately to the east of Mizar is 4th magnitude Alcor (80 Ursae Majoris). Alcor itself is a spectroscopic binary, but being about 1/4 light year from Mizar, the two are probably an optical double. (Note: each of these stars is a spectroscopic binary as well.)

      What are the definitions for an optical, a visual, and a spectroscopic binary star? (Refer to your lecture notes.)

    2. If you observed the double star Albireo, comment on the color and apparent size of these two stars. What astrophysical reason can you give for why these two stars are different colors?

  4. Deep Sky Objects: For your observations of the galaxy, clusters, or nebulae, can you resolve any of these objects into stars? Why or why not?

© 2003 Weber State University
Revised: 24 April, 2003