Over the course of your semester of astronomy, you must complete an observing project, which will be worth 1/6 of your laboratory grade (5% of your total grade and about twice as much as any other lab) and which will be presented to your classmates, instructor and a couple of independent evaluators at the end of the semester. A rubric for the poster presentation can be found on the course website.
Listed below are brief synopses of the eight options along with required materials and cautions about common mistakes. Detailed descriptions of each lab as well as the questions you will be expected to address in your report are available on the course website. You may also design your own observing lab or modify one of these options, but must clear it with me in person or by e-mail before September 30.
Also available on the course website are “tips” on each of the individual observing projects from your AST102IN colleagues last semester (except for options 6 and 8, which are new this semester). I recommend that you check these comments out before choosing a project.
Weather
Although we live in the land of few clouds, there will occasionally be a night or two when you will be unable to make your observations due to weather. This is fine so long as you complete the minimum number of observations outlined in each lab. All of these projects involve more than one night of observing, and many of them take weeks or months to complete so START EARLY. Incomplete labs will be heavily penalized.
Equipment
Most of these labs can be completed without any equipment other than your eyes and simple materials that we will construct in class or that you can easily make at home .If you would really like to do a lab that requires equipment you don’t have, come see me. I have a couple of Galileoscopes, binoculars, shutter cables, etc. that I am willing to loan out.
Photography
If you have a camera you may want to consider experimenting with astrophotography as a means of recording and presenting your data. In fact, there is a lab option entirely on astrophotography if it interests you. HOWEVER, students who choose to use a camera to record data frequently fail at their semester observing projects because of camera issues, as camera failure is not an excuse for not completing your project. You need to be careful about checking what you have (developing frequently if using a film camera, examining digital images carefully), saving your data in an appropriate place, avoiding overexposure and completing relevant backups (sketches, etc.). I have a fair amount of experience with astrophotography, so bring your camera to class and I’m happy to help you figure things out, but do it early so that you still have plenty of time to complete the lab!
Midterm Check In
Some of these labs require observations over the course of an entire semester. Some I will only allow you to do if you get a head start on them. You will be asked to tell me which lab you’re doing around the date of the midterm. If you have not yet begun at that time, you will not be allowed to choose Options 1-5 and will be left with 6-8. Options 1 and 2, in particular, need to be begun near the beginning of the semester. The general rule of thumb is that the labs that are spread over the course of the semester require fairly simple observations and the smaller the interval of time in which the lab can be completed, the more difficult the observations themselves become.
Option 1: Change in the Position of Sunset
Find an unobstructed view of the western horizon somewhere that you can return to approximately once per week over the course of the semester. Using either a sketch or camera, record the changing position of the sunset over the course of the semester.
Minimum: 10 observations spread over at least 2.5 months
Materials: compass, camera (optional)
Cautions: You have to observe from EXACTLY THE SAME LOCATION (as in feet in the same place) every time. If you choose to track the changing location of sunset with a camera you MUST have the camera on the same zoom every time. You also need to observe against a relatively unobstructed horizon with some recognizable distant landmarks (mountains are ideal for this). A backup sketch is always a good idea, even if you plan to present photographs for the final product.
Option 2: Planetary Motion
Track the movement of the two naked eye planets visible in the evenings this semester (Mars and Jupiter) relative to the stars in that portion of the sky. Make your observations once per week over the course of the semester.
Minimum:10 observations spread over at least 2.5 months
Materials: Planisphere, camera (optional)
Option 3: Moon Phases
For at least 14 days from the date of a new moon, go outside at exactly the same time (which must be within approximately 30 minutes of sunset) and record the position and phase of the moon relative to a detailed sketch of the horizon, being careful to accurately record its location, size and orientation. You will measure the moon’s altitude above the horizon and apparent size using simple instruments.
Minimum: 12 observations over 14 days
Materials: Astrolabe, calculator, camera (optional)
Cautions: You have to observe from EXACTLY THE SAME LOCATION (as in feet in the same place, and camera on same zoom) every time. If you choose to track moon phases with a camera you MUST have the camera on the same zoom every time (so that the same landmarks appear on the horizon) and you MUST NOT overexpose the moon in your pictures (you need to be able to clearly see the phase!). A backup sketch is always a good idea, even if you plan to present photographs for the final product.
Option 4: Astrophotography
Using a 35mm camera and a shutter cable or a digital SLR camera, you will take photographs of a number of objects including: several constellations, star trails, at least two deep-sky objects, a planet, and the moon. Astrophotography is a hobby of mine and I’m happy to help, but you need to approach me for help EARLY in the semester.
Materials: 35mm camera with shutter cable and film OR digital SLR camera capable of taking at least a 30 minute exposure (may require an external remote)
Caution: People who do not do well on this project typically fall into two categories: (1) They wait too long to begin the project and end up with very few useable photographs (typical for those using 35mm cameras where you can’t tell if an image turned out until the film is developed) or (2) They get very creative with the pictures they’re taking but fail to follow directions or to do any science with or analysis of their photographs. This lab is not just about taking pretty pictures!!!!
Option 5: Observe a Variable Star
Choose a well-known variable star (such as Algol, Delta Cephei, Delta Scorpi, or Mira) and measure its brightness relative to several nearby non-variable stars both with the naked eye and through a pair of binoculars or a small telescope. You must complete at least 10 observations of the star’s brightness spread over at least two full periods of brightening and dimming (which vary depending on the star – some vary over days, and some over weeks or months)
**Note: you must have a pair of binoculars or a small telescope to do this experiment
Materials: Planisphere, astrolabe, camera (optional)
Caution: Particularly for short period variables, this lab may involve observing a star several times in one night spread over the course of the night for a couple of days in a row. If you don’t want to have to stay up late, choose a star with a long period so that you can observe it just once per night over the course of several weeks.
Option 6: Sunspots
Construct a solar viewer and use it to record the changing location of sunspots. This requires that there be one or more visible groups of sunspots when you begin your observations. You will use your data to calculate the rotation rate of the sun.
Minimum: 10 observations over 2 weeks.
Materials: Solar viewer (tinfoil, safety pin, paper plate, white paper), binoculars or small telescope (optional)
Option 7: The Eratosthenes Experiment
If you will be traveling 150miles or more due north or south this semester, you can attempt to recreate Eratosthenes’ experiment measuring the size of the Earth by finding the altitude of the North Star from each location. You will use your data to calculate the circumference of the earth and the error in your measurement.
Materials: Astrolabe, calculator
Caution: Phoenix is not far enough away and San Diego and LA are not far enough North/South! This is a good option only if you are traveling somewhere north of about Flagstaff (East/West doesn’t matter so anywhere in the US North of Flagstaff) or south of Hermosillo in Mexico.
Option 8: Telescope Hunt
Using a small telescope (Galileoscope or your own), find at least 10 deep sky objects from 5 different categories (binary stars, nebulae, galaxies, planets, star clusters) and sketch them. Calculate the field of view of your telescope. Note that you are welcome to borrow a galileoscope, but will need to find a tripod to use it with.
Materials: telescope, stopwatch, planisphere
Caution: Galileo was a very impressive and patient man. Although Galileoscopes are a remarkable contribution to the field of low budget astronomy, they are very difficult to use, and virtually impossible to use without a tripod. If you choose this option, you will need to be very patient.