Telescope Lab, Philip, Brooke and Megan

Telescope Lab

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Philip Goudeau, Brooke Masterson and Megan Purgahn

AST 115 H, Plavchan

Due April 16th, 2016

Purpose:

The purpose of this lab was to identify and observe astrophysical objects in the night sky with the aid of a telescope.

Introduction:

The invention of the telescope 400 years ago and its first use by Galileo Galili to look at the sky changed our perceptions of the heavens forever.  Telescopes are important in astronomy and it is important that those learning astronomy learn how to use them properly and understand how they work.  There are multiple types of telescopes, like refractive telescopes using lenses and reflecting telescopes using mirrors. At Baker Observatory we have 8-inch primary mirror telescopes for you to use, with tracking motors to maintain the positions of stars in the eyepiece. We also have two 16-inch telescopes and one 14-inch telescope used for research by our faculty.

Procedure:

Supplies needed:

A free app for your phone like StarChart for Android and iPhones

A telescope

Paper to take notes to type up later

Messier catalog and star-charts

1. Identify a group of students to work with, so that there are enough telescopes per student to go around.  
2. Set up the telescope as directed by the instructor.  Please be very careful in handling this expensive equipment.  Give your eyes time to adapt to the darkness.  Use only red flashlights to preserve your “dark sky adaptation.”
3. Find a very bright star or the moon to look at.  Use the finder-scope (the little telescope piggy-backing on the big main telescope) to align the bright star or moon in the direction the telescope is pointed.  If there is no finder-scope, use your best judgment (it’ll get better with practice!) to align the telescope direction with what you want to look at.  If there is a finderscope, center the target in the cross hairs.  To look through both the finder-scope and main telescope, it is best to close one eye.  
4. Once the telescope is aligned in the direction you want it, find the bright star or moon in the eyepiece of the big telescope.  This is not easy the first time, and takes practice.  Use your hands to carefully nudge the telescope in one of two directions to “search” the nearby part of the sky to find your target.  If you telescope is out-of-focus, star will look like “donuts”.  Focus the telescope.  If you have a finder-scope, note the position of the bright star or moon now in the finder-scope, so that you can more easily position and acquire stars in the future.  Often the finder-scope and main telescope aren’t perfectly aligned.  For Baker Lab #2 only: Why does the telescope need to be focused?  What are you changing when you turn the focus knob?  
5. For Baker Lab #2 only:  With the tracking turned off, watch the stars in your field of view in the eyepiece.
1. How long until they drift all the way across your view?
2. Why are they drifting
6. Turn tracking on the telescope on.  From the following list of object (and the messier catalog provided in your lab packet), pick one object to observe in your group.  It is best to start with a bright object like the moon or a bright star or planet, and work your way to fainter and fainter objects as you gain more experience in each lab.  
1. Part of the Milky Way
2. Andromeda Galaxy
3. Orion Nebula
4. Jupiter
5. Saturn
6. Mars
7. Moon
8. A double star
9. An open cluster, including the Pleiades and Beehive Clusters
10. A globular cluster
11. A planetary nebula
12. Any other object approved by the Instructor
7. Using your star finding app or chart, locate your object in the finder-scope.  Then after aligning the object in the finder scope (or the general vicinity), locate the object in the eyepiece of the main telescope.  
8. Answer the following questions:
1. Draw what you see.  If the object is bright enough, take a picture with your phone up against the eyepiece, and include that in your report.  If your hand is steady, and the telescope tracking is good, you can use a custom smartphone app to take a longer exposure of fainter objects.  Make sure the flash is off.
2. Make notes about distinguishing characteristics and properties of what you are looking at.  For example, if you are looking at a binary star, how far apart do they appear to be?  Can you see if the two stars have different colors?
3. If your object is a planet, can you see any moons? How many?  Do you know what they might be named? Can you see any features on the surface of the planet, and if so, what are they?  Can you see any rings around the planet? Ask your instructor.
4. If your object is the Moon, what craters, maria and other features can you identify?
5. How bright is your object?  What would you estimate the magnification is of your eyepiece?
6. Can you see more stars with the telescope than you can see with your eye?  Particularly with the milky Way? Why is that?
7. If you are looking at a star, a cluster of stars, or a binary star, why can’t we see the surface of the stars?  Hint: calculate the angle a star’s surface has on the sky, given the typical distance to a star and the typical size of a star in diameter.  
8. For lab #2 only, put your hand (or someone else’s) over part of the telescope, partially covering your view while still looking through the eyepiece.  Can you see the outline of the hand?  If not, why not?  What happens to your view when you do this?
9. If your object is changing in brightness, why is that?
9. Once the instructor gives the OK, take down and put away your telescope.
10. Once you get back to campus, write-up your lab report.  Include a two-paragraph description of information about your target that you have learned in class or researched online and from the textbook.  

Description:

    The object that we observed on April 6th was the planet Jupiter. Jupiter is by far one of the most interesting planets in our solar system. It is the largest planet in our solar system. With such a large size, it is 318 times more massive than the Earth, and it is possible to fit 1,000 Earths inside of Jupiter. Jupiter’s structure is very different from the Earth. It has a low density of 1.33 g/cc because it is made up of mainly the gases Hydrogen and Helium. It has a gaseous top layer, with a liquid middle, and a small rocky core. Its visible outside layer is very unique in that it appears to have “stripes.” These stripes are the different atmospheres that Jupiter has. One of the stripes, or bands, has The Great Red Spot, which is an enormous storm of the surface.

A lesser known fact is that Jupiter also has extremely faint rings around it that are not very visible but are caused by its many moons. In fact, Jupiter has 63 moons. Some of its most well known moons are Io, an extremely volcanic moon that resides closest to the planet. Ganymede, Europa, and Callisto are three other of Jupiter’s largest moons. From the telescope we were able to spot Europa and Ganymede. Also visible from the telescope were two bands of color on its surface. That was the atmosphere of the planet. Jupiter was an easy object to observe because it was the brightest object in the sky that night.

Results/Observations:

**We were unable to answer all questions due to time constraints, weather forecast, and our skill level, but here are the results that we were able find and record:

4.) Why does the telescope need to be focused? What are you changing when you turn the focus knob?

1. The telescope needs to be focused in order to see the object in the sky clearly. When we turn the focus knob we are changing the magnification of the telescope, causing it to zoom in and out and focus on certain objects.

5.) With the tracking turned off, watch the stars in your field of view in the eyepiece. How long until they drift all the way across your view? Why are they drifting?

1. We recorded the amount of time it took for the star to cross our view and it took approximately 1 minute and 50 seconds.
2. The reason the stars seem to be drifting is because the Earth is constantly rotating. It takes the Earth 23 hours and 56 minutes (or 86,160 seconds) to make a 360 degree rotation.

6.) Pick one object to observe in your group.

1. We chose to study Jupiter on this night because it was the brightest object in the sky.

8) Answer the following questions.

1. Draw what you see or provide a picture.  
1. These photos were taken from an Iphone:
2. 
2. Make notes about distinguishing characteristics and properties of what you are looking at.
1. Jupiter has two parallel and diagonal lines going through its surface.  There is one small star/moon below Jupiter that is pretty small and close to Jupiter (easy to miss).  There is another star/moon above Jupiter too, but we are pretty sure it is a moon of Jupiter.
3. We were observing Jupiter, which is a planet in our solar system.  We think that we observed two of its moons that night.  We think that they were Europa and Ganymede from our comparisons between what we saw and what other astronomers saw with their telescopes online.  
4. (Our object was not the Moon, so we didn’t observe its distinguishing characteristics)
5. Our object was the brightest in the sky.  I estimate the magnification of our telescope’s eyepiece was 100.  
6. There were more stars visible without the telescope. This is because with the telescope we only focused on one region of the sky, and in total we saw less. Overall though, if someone was to look at the entire sky with a telescope, they would see more due to the magnification.
7. **Our teacher didn’t expect us to answer the question about why we can’t see the surface of the stars **
8. In this question, we were asked to see what would happen when we put someone’s hand over the telescope lens while someone was still looking at Jupiter through the eyepiece.  When we used our hands to cover the image, the person viewing Jupiter did not see any difference in brightness.  We took it a step farther by covering the telescope with a piece of paper.  When we did that, Jupiter’s brightness dimmed.  Again, we took it a step farther.  When we covered the telescope with a clipboard, the person viewing Jupiter watched it disappear in three seconds time.  Then, as scientists do, we tried not to obstruct the view, but to change it.  We shined a red flashlight into the telescope lens.  The view of Jupiter turned very red.  

    We think that our hands did not block enough of the telescope’s ability to see the light from Jupiter.  The telescope’s lens was bigger than two hands put together, so our guess is that the light collected by the telescope was unaffected when our hands were trying to block the view.  Paper, however, was able to dim the light of Jupiter.  We think this was possible because the paper we used was bigger than our hands, therefore it covered more of the telescope’s lens.  The dimming was probably caused by the paper itself being thick enough to block some of the light off the planet but not all of it.  Of course, the clipboard was very thick and completely blocked the view of the planet.  We think the time difference between the clipboard being placed in between the telescope and the disappearance of Jupiter in the eyepiece was because the light from Jupiter had to travel a long distance to get to our telescope - so our telescope took a couple of seconds to get the new information that the light wasn’t coming anymore.  

9. We were asked if our object (Jupiter) was changing in brightness. No, it was not changing in brightness because the telescope makes up for the Earth’s atmosphere which usually causes stars to twinkle. Due to the technology of our telescope Jupiter remained clear and at the same level  of brightness the entire time.

Conclusion:

After wrapping up with this lab, we believe to have a basic understanding of the function of a telescope. We learned the basics of setting up the equipment along with how to go about finding objects in the night sky with it.  

Extra Credit:

1. What was the satellite that we saw that night speeding across the night sky?
       The satellite we think passed us at approximately 8:40pm was the CZ-2C RB.  I found this information on the site attached when I entered in the date April 6th, 2016.  https://in-the-sky.org/satpasses.php

2. What phase was the moon in so that we could not see it in the night sky between 7 to 10pm?  

              On April 6, it was in the New Moon phase.