Introduction to Astronomy Lab

Physics 091, Spring 2020

The laboratory associated with Introduction to Astronomy.
Revised: February 12th, 2020
Instructional Team

This lab is the corequisite (required companion) to Physics 90. You will do experimental work to round out your understanding of: light; optics; the constellations and the celestial coordinate system; the motions of the Moon, the Sun, and the planets; and telescope operation.


Together, the lecture and laboratory of the Introduction to Astronomy course are designed to achieve the outcomes enumerated in the Mathematical and Scientific pathway to knowledge. The laboratory portion of the course has three main outcomes:


The indoor lab topics are star charts, reflection, refraction, lenses and spectra. The outdoor lab topics progress from no instruments to advanced instruments: naked-eye observing, binocular observing, and a sequence of three labs using German equatorial mounted refractor telescopes.

All labs are conducted on Wednesdays, except the make-up lab, which will be conducted on Thursday, April 30th in coordination with the Seminar Informal Curriculum schedule.

Afternoon labs for Section 1 are conducted between 4:30pm and 6:30pm; and for Section 2 and 3 between 6:30pm and 8:30pm.

Evening observing labs for all three sections begin at about sunset. Sunset varies a lot during the semester. For example, if we had had an outdoor lab on February 12, we would have met about 5:30pm because sunset is about 5:45pm in Moraga on Feb. 12. Sunset on Thursday, April 30th is about 8:00pm.

We will watch the weather and weigh in other factors (like the Moon phase) and email you by noon on Monday to tell you whether you have an indoor or an outdoor lab on that Wednesday. You should not continue in Physics 90 and 91 if you have other Wednesday evening commitments.

For the Spring Semester of 2020 there are 12 Wednesdays from February 19 to May 13. We will try to keep a balance of five indoor labs and five outdoor observational labs. Obviously we don't have perfect forecasting, especially with the very variable spring weather, and therefore one of the Wednesdays is budgeted for one outdoor lab cancellation. On two recent springs we have been limited to just four outdoor labs, and when that happened, we have counted the star charts lab as if it were an observing lab.

Outdoor Labs

The outdoor observational labs are held at the SMC Campus Observatory Pad. Most of you have passed this while walking to the Cross.

If you aren't familiar with the location, these campus observing night directions directions will likely be helpful:

At present the following outdoor labs are planned:

The telescope observing labs will start with easy (large, bright) targets selected from those that are available in the early evening, and proceed toward observation, including note-taking and drawing of more difficult targets. Targets will range over all of those discussed in the course: the Moon, the planets, double stars, clusters, novae, and galaxies. The last two types of objects are extremely difficult to see due to light pollution. We will nonetheless attempt to find some of them.

Indoor Labs

At present, the following indoor labs are planned:


The Physics 91 lab grade is separate from the Physics 90 lecture grade. For each lab, one of the following scores will be recorded.

There are 100 points possible for the 10 labs. There are no "allowed" absences. However, as noted above, we will provide one makeup lab on Thursday, April 30th, so if you miss one lab and did the makeup and all the others perfectly you could still manage to get a perfect score.

Since you will not receive any credit for an absence, and since there are 10 labs required, each absence will in effect subtract 10% from your final grade. Final letter grades will be assigned as follows: 90-100% is the A range, 80-89% is the B range, 70-79% is the C range, 60-69% is a D, and 0-59% is an F.


The Stem Center Tutoring, Academic Honor Code, and Student Disability Services statements from the Physics 90 syllabus are also applicable to Physics 91.

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