- TRIAL USE OF YOUR STAR AND PLANET LOCATOR - MODULES 1, 2 AND 3 6
MODULE 1 6
MODULE 2 6
MODULE 3 6 - EXTRA CREDIT QUESTION: RECORDING OBSERVATION OF A BRIGHT CELESTIAL OBJECT - MODULES 1, 2 AND 3 6
MODULE 1 6
MODULE 2 6
MODULE 3 6
MODULE 4: ANGULAR SIZE, DISTANCE AND PARALLAX 7 - ANGULAR SIZE VERSUS DISTANCE 7
TABLE 1 – RELATION BETWEEN DISTANCE (CM, ETC.), ANGULAR SIZE AND PHYSICAL SIZE 7 - DISTANCE, ANGULAR SIZE AND ESTIMATED PHYSICAL SIZE 7
TABLE 2 – ESTIMATING PHYSICAL SIZE OF A DISK FROM ANGULAR SIZE AND DISTANCE 7 - DISTANCES BY PARALLAX 7
TABLE 3 – ESTIMATING DISTANCES BY PARALLAX 7 - EXTRA CREDIT: ANGULAR SIZE VS DISTANCE PHOTOS AND DISCUSSION 8
- “PARALLAX OBSERVATIONS” DATA AND CALCULATIONS 8
TABLE 3 – ESTIMATING DISTANCES BY PARALLAX 8 - EXTRA CREDIT: PARALLAX PHOTOS AND DISCUSSION 8
MODULE 5: PROPERTIES OF LENSES AND TELESCOPES 10 - FOR FULL CREDIT, AFTER ASSEMBLY, MAKE A PHOTOGRAPH OF YOUR OWN TELESCOPE AND INSERT IT HERE. 10
- ENTER YOUR MODULE 5 OBSERVATIONS OF THE FUNCTION OF THE EYEPIECE AND OBJECTIVE LENSES OF YOUR TELESCOPE KIT. 10
TABLE 1 - FOCAL LENGTH 10
TABLE 2 - TELESCOPE EYEPIECE LENS MEASUREMENTS 10 - “OBSERVED VERSUS THEORETICAL TELESCOPE MAGNIFICATION” OBSERVATIONS AND CALCULATIONS 11
TABLE 3 - OBSERVED VERSUS THEORETICAL TELESCOPE MAGNIFICATION 11 - “LIGHT GATHERING POWER ” OBSERVATIONS AND CALCULATIONS 11
TABLE 4 - LIGHT GATHERING POWER 11
MODULE 6: SPECTRA OBSERVATION 13 - OBSERVING, PHOTOGRAPHING AND IDENTIFYING TYPE OF STREET LAMPS 13
QUESTION 13 EXAMPLE 13
MODULE 8: EARTH’S MOON 14 - EXTRA CREDIT: MAKE A CAREFUL DRAWING OF WHAT YOU SEE THROUGH YOUR TELESCOPE OR BINOCULARS OR LARGER TELESCOPE. 14
MODULE 12: EXPANSION OF THE UNIVERSE 15 - INSERT THE SCAN OR PHOTO OF YOUR RECESSION VELOCITY VERSUS DISTANCE PLOT HERE. 15
- ALSO FILL OUT YOUR CALCULATION OF H AS FOLLOWS: 15
Observational Notebook
Instructions
• You should complete the following observational or calculation activities marked 1,2, 3, etc.
• Photos:
o In addition to the items described in the modules, an electronic or phone camera will be useful. More points will be awarded for photographic documentation.
o Any procedure that creates a picture that can be pasted into and attached to the notebook will be OK.
o Note: information is attached to pictures detailing when taken etc. so do not use old ones from previous semesters or other people’s photos!
• Whereas you may work with others, it is very important that the work is your own. For example: take your own photos and make your own measurements
• Grading:
o Questions are worth 8.33 percent each.
Example
Here is an example of the type of information you should submit for this activity and other observational activities. Type your observations normally directly into this Word document. The italics below are meant to delineate the example from my bolded instructions.
First rough directions of west, east, north and south were established for the observing location using the setting point of the sun and a map of the locality from Google. You can use ordinary maps, a compass or ever a compass app on a smart phone.
The sky was observed at 5:45 am on October 14, 2008. Following the instructions on the Locator, in its instruction book, and in Modules 1-3, the Wheel was turned so October 14 to match 5:45 am on the pocket.
Here is a photo of the Locator set for that time and date in Figure 1.
Figure 1: October 14, 5:45 AM
Going outside, it was cloudy, but a really bright object was visible toward the east. Checking Table 1 on the back of the Locator, for October 2008, Saturn was found to be in the constellation Leo, which would be toward the east. In the Locator Window, the abbreviations for the constellations in Table 1 made it easier to use than the old Locator described in the module. It was too cloudy to see the bright stars Procyon (nearly overhead) and Sirius (low to the south and a bit toward the west).
Figure 2
So even with the cloudy sky and no bright stars visible, this planet could be identified!
To document this discovery, a picture taken with an ordinary electronic camera is shown which has the image of the bright planet penetrating through the clouds.
As described in the Star & Planet Locator instruction book, the planet Saturn did not twinkle like a star but instead gave a steady light. In contrast, the camera was not held steady. For future observations perhaps it should be braced on top of a steady object like a parked car to get a better photo. A wait was required to get a break in the clouds to record the image. This picture has not been cropped but it was squeezed to fit. You should append the photo as a file if possible.
Remember the typical camera can only record rather bright objects by itself. Turn off the flash. It will not help for astronomical objects.
Modules 1, 2, and 3: Star and Planet Locator
Your task for modules 1, 2 and 3 is to use your Star & Planet locator to find what is visible on a given date and time. Document this with a description of what you saw :(bright stars, planets, and moon. (Questions to follow example)
- Trial Use of Your Star and Planet Locator - Modules 1, 2 and 3
• Following and improving on this example, use your Star & Planet Locator to identify predicted location and, if possible, documented observation of a bright planet or star. See the bright star list on the back of the Star and Planet Locator.
• Insert your description below, under the appropriate module.
• Give the date and time.
• Include a scan or a cell phone photo of the locator for that date and time like that in Figure 1.
• List a couple of conspicuous object that will be up and describe about where they would be found in the sky.
Module 1
Module 2
Module 3
- Extra Credit Question: Recording Observation of a bright celestial object - Modules 1, 2 and 3
Photograph, post here or attach observations of one of the bright objects you predicted to be up in Question 1. Give full details of its appearance and location in the sky (overhead, east west etc).
Module 1
Module 2
Module 3
Module 4: Angular Size, Distance and Parallax
Follow the procedures and instructions described in the Module 4 Lab for entering or describing your results below. Questions 6 and 7 are for extra credit, however, credit will only be given for one. You may select which one to answer.
- Angular Size versus Distance
Table 1 – Relation Between Distance (cm, etc.), Angular Size and Physical Size
Physical Size of Object:
Position Measured Angular Size Measured Distance Formula Ang. Size % Error
1
2
3
- Distance, Angular Size and Estimated Physical Size
Table 2 – Estimating Physical Size of a Disk from Angular Size and Distance
True physical size:
Angular Size Distance Estimated Physical Size % Error
- Extra Credit: Angular Size vs Distance Photos and Discussion
• Take two photos, one close and one farther away of a friend or a standard size object such as a Coke can.
• Post both photos here.
• Count the number of paces between you and the close up position, say three long paces.
• How could you figure out how far, in paces, your friend is at the more distant position? - “Parallax Observations” Data and Calculations
Table 3 – Estimating Distances by Parallax. Repeat the object 3 protractor measurement and calculations so that you get the same results as in the Table 3 boxes. Then do everything in the same way for objects 1 and 2, filling in the table.
• Baseline = 2r = __2 AU _; r = __1 AU___
• Measured Smaller Distance #1 =
Object Angle S Parallax Angle Calc. Distance % Error
1
• Measured Middle Distance #2 =
Object Angle S Parallax Angle Calc. Distance % Error
2
• Measured Largest Distance #3 = 23 AU
Object Angle S Parallax Angle Calc. Distance % error
3 4.5o 2.25o 25.5 AU 11%
• Discuss below how well your observations of distances via parallax compare to the actual measured distances. Which have the best or worst agreement?
- Extra Credit: Parallax Photos and Discussion
• Take two photos of a fairly nearby object or friend say several paces away.
o In one put the camera lens over your left eye.
o In the other, the camera lens should be over the right eye.
o For a cell phone turn on the camera and use your thumb to see the location of the lens on the other side of the phone.
o The screen image will go blank when you find the lens.
o Post the photos here.
o Count the number of paces between you and the close up position, say three long paces.
• Now have the friend or object at a position several times more distant and take another pair of photos. Post them here.
o How can you determine from the photos that the friend is more distant in the latter pair?
o How could you figure out how many times farther your more distant friend’s position compared to the closer using parallax & angular size?
Module 5: Properties of Lenses and Telescopes
- The Function of the Parts of the Kit Telescope Open your telescope package and separate out the two lenses, tubes and blue caps to hold the lenses.
- Enter Module 5 observations for the eyepiece and objective lenses
Table I - Focal Length
First larger “thin” objective lens data: Example - Focal length in cm= fest, 1 = 44.4 cm (measured with a meter stick)
- Estimate the image size. Large. A couple of inches in diameter.
- Is the image real? Yes.
- Is the image right-side-up or up-side-down? Examine Fig 4b, c and answer.
Second smaller “fat” lens data: Measure this yourself with kit ruler - Similar to Fig. 4a measure with kit ruler the Focal length= fest, 2 =
Photo setup and post below. - Compare Fig. 4d eyepiece image size to the Fig. 4c objective image size?
- Is the image real?
4, Is the eyepiece image upright or upside down? Fig. 4d hard to see. To create a larger image of a source (lamp, window etc) move the lens and screen closer to the source. Try Fig. 6. Photo your set up and post.
Post Table 1 photos here.
Table II - Telescope Eyepiece Lens Magnification
“Fat” eyepiece lens data looking at a magnified image of a printed page:
Focal length= fest,fat = _. Get from Table I
Hold the eyepiece lens on a printed page. Slowly move it outward keeping it close to (less than one focal length from) page so the image seen through the lens is magnified. Review the module text on magnifiers.
Is the magnified image real or virtual?__________
Is the magnified image right-side up or up-side down? Try it yourself and review Figure 9b to answer.
- “Observed versus Theoretical Telescope Magnification” observations and calculations
Table III- Observed versus Theoretical Telescope Magnification
Measured Magnification = (width with telescope)/(width without telescope) =
(_) / (_) = __
The theoretical magnification of a telescope is approximately equal to the focal length of the objective divided by the focal length of the eyepiece.
Record the objective lens focal length fo = 44.4 cm_______(units?) from your earlier Table I measurement.
Record the eyepiece focal length fe = _______(units?) from your earlier Table I measurement.
Calculate the theoretical telescope angular magnification mag =
fo/fe =
_ / _ = _____
How does this agree with the results from the two photos in Figure 12?
Go to next page.
- “Light Gathering Power ” Observations and Calculations
Table IV - Light Gathering Power
Figure 13 shows two photos of a light bulb source images formed by the objective lens, the left formed by the full aperture and the right by the aperture covered by half.
how the image changed as more of the objective was covered.
• Describe how the image changed as more of the objective was covered.
• Considering how the image changed, explain why this happened
The amount of light gathered by a telescope objective depends on its area.
• Measure the diameter of kit telescope’s objective lens in cm, diameter =
• Compute the radius, r = (diameter/2) =
• Compute area of objective = πro² =
The radius of the opened iris of the dark adapted eye is about 0.3 cm.
• Compute the light gathering power of your telescope compared to the eye =
πro²/(πre²) = (ro/re) ² =
From these results explain why astronomers build telescopes with 10 m diameter objectives to explore deep into space.
Module 6: Spectra Observation
- Observing, Photographing and identifying Type of Street Lamps
Question 13 Example
• Street light emission line spectra photos are shown below.
• These are not exactly thin gas due to coatings etc. to improve color etc.
• Mercury light top.
• Sodium at bottom.
• Use your grating & camera to photo street lamps.
o Just put the grating of your glasses over the camera lens and snap the photo.
o You may have to put the light on one side to see one of the spectra clearly.
• Compare your photos to the photos here and in the module and lecture. Identify the element of streetlights. For full credit post your street light photos in Observing Notebook here or attach as a file.
Module 8: Earth’s Moon
- Extra Credit: Make a careful drawing of what you see through your telescope or binoculars or larger telescope.
• You can observe the Moon with your kit telescope and a camera as extra credit.
• Try to identify any features (mare regions, highlands, craters?).
• Photograph or scan your drawing and include or attach it to this assignment.
• Describe what you see along the terminator (day night line) if it is visible.
• Try getting a photo of the Moon by setting up your telescope in its aluminum foil box mount on a table, pointing it at the Moon, and focusing until the image is sharp.
• Try on a nearby streetlight etc. to get an initial focal position.
• Sight along the scope to get pointed at the Moon.
o Then hold the camera lens just outside the eyepiece lens as was done for the view of the door in the telescope module lab.
o Hold a camera behind the eyepiece to see if you can take a photo of the moon like we did of the doorway. Module 12: Expansion of the Universe
Module 12: Expansion of the Universe - Insert the scan or photo of your recession velocity versus distance plot here.
- Also fill out your calculation of H as follows:
• Paste the following calculation with your graph in this “Observing Notebook”
• V1=0 and D1=0 correspond to the Milky Way Galaxy
H from all of Table 12.1
H = [(…………..=V2) - 0 ] / [.( D2) - 0 ] = _________