Baker Lab 3 -- Caleb Skocy and Seth Dowler

Caleb Skocy and Seth Dowler

AST 115 Honors

Baker Lab #3

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. Since then telescopes have changed a lot, from the first refractive telescopes using lenses, to reflecting telescopes using mirrors. The very first reflecting telescope was designed and built by Isaac Newton. Today, the biggest telescopes are made with mirrors and segments of mirrors spanning 10 meters in diameter. Within the next two decades, the next generation of telescopes will come online with primary mirror diameters stretching 25-40 meters across!

In this lab, we were able to return to Baker Observatory and practice our skill with telescopes once more.  We once again used the telescopes to observe objects in the night sky.  We were to choose two astronomical objects to study, and we chose the Moon and Messier 40.

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

Procedures

A. Set Up the Telescope

To set up the telescope, follow the directions from Baker Lab #2 below.

http://ast115h.blogspot.com/2016/04/purpose-in-these-exercises-wemade-use.html

B. Observing Objects in the Night Sky

1. From the following list of objects (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.

2. 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.

3. Answer the questions (from the lab packet) concerning the object(s) you observed.

4. Once the instructor gives the OK, take down and put away your telescope.

Results and Discussion

A) Questions and Answers

1. The Moon

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?

• The appearance of the moon was mesmerizing. We could see it up close, the edges and the crispness of its imperfections. Even our pictures of it turned out well on our phones, one of which is displayed above. The moon appeared brittle, a bit like dried glue, though it is much more luminescent. Additionally, it appeared to be serrated on its edges due to the presence of craters on its surface; on its face, the craters were also visible, fully visible: were very small though, and were overtaken in size by the shaded portions, which were maria.

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?

• We were able to identify many formations on its surface. The most prominent maria structures we saw were mare serenitatis, oceanus procellarum, mare imbrium, and mare humorum. The most visible craters were plato crater and copernicus crater.

5. How bright is your object? What would you estimate the magnification is of your eyepiece?

• The Moon was very bright, being nearly in its full phase.  The Moon appeared to be around 50x as large when viewed through our telescope as with our naked eye.

6. Can you see more stars 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 stars 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?

2. Messier 40

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?

• These two stars appear to be a binary star system.  The two stars look like they are very close together.  They both appear slightly bluish in color.  The star on the bottom right appears to be much larger than the star on the top left.

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?

• We were unable to see Messier 40 with our naked eyes, and it was not very bright, even when viewed through the telescope.  The magnification of the telescope has to be at least 50x, since we were able to see it clearly though.

6. Can you see more stars than you can see with your eye? Particularly with the Milky Way? Why is that?

• Yes, because the light gathering power and magnification of the telescope is much greater than the naked eye.  This allows us to see that there are two stars here, rather than nothing or the single speck of light that we would see with our naked eyes.

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 stars surface has on the sky, given the typical distance to a star and the typical size of a star in diameter.

• We can imagine an object somewhere near the size of the Sun being so far away that it looks to be about the same size as the objects in Messier 40.  It would be hard to distinguish anything about the surface of an object which is so far away.

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?

B) Information About Observed Objects

The Moon:

As for facts about the moon: the moon is a satellite of Earth; its diameter (2,159 miles) is one-fourth that of Earth. Its total surface area is 14,658,000 square miles. Only about 65% of the moon's surface is visible from Earth. Additionally, we always see the same side of the moon from Earth, while the other always remains hidden.

Other facts about the moon include its lack of atmosphere: there's no wind on the earth. As such, the footprints from the Apollo 11 Mission remain there today, since being pressed into the moon's surface in 1969. Related to this, the moon's gravity is less substantial than the Earth's, due to its smaller mass: 100 pounds on Earth would equal 16.6 pounds on the moon. Despite its lessened gravitational pull on objects on its surface, it still exerts an equal pull as the Earth exerts on it. As such, tidal waves on the Earth are due to the pull of the moon's gravity on it.

Messier 40:

Messier 40 was discovered in 1764 by Charles Messier.  He found this while searching for a nebulae reported to be in the vicinity by Johann Hevelius.  Though Messier recorder the description and measurement of these objects accurately, nobody was able to identify this pair for almost two-hundred years.  It was also rediscovered separately by Friedrich August Theodor Winnecke in 1863, and named Winnecke 4.  When Winnecke recorded Messier 40, they had visual magnitudes of 9.0 and 9.3, and were separated by about 49 seconds of arc.  Messier 40 was taken to be a binary system.

Since Winnecke’s discovery, there have been investigations of Messier 40.  The distance separating the two stars has increased from 49.2” in 1863 to 52.8” in 1991.  Research by Richard Nugent in 2002 shows that Messier 40 is probably an optical double star rather than a binary star system.  A binary star system is where two stars are orbiting each other around a common center of gravity.  Messier 40 being an optical double star means that the stars simple appear to be close together as seen from Earth.  In reality, one of the stars is much further away, and the other closer.

Conclusion

In this lab, we once again returned to Baker Observatory.  It was much easier to set up and use the telescopes this time, having now had some experience.  Since the Moon was near to its full phase, the visibility of other objects was poor.  Even with the poor visibility we were able to observe many stars, including Sirius and Betelgeuse.  For the objects we chose to observe for our report, we looked at the Moon and Messier 40.