Category: Astronomy

Assignment:
1. Go outside on a clear night, wait 15 minutes for your eyes to adjust to the dark, and look carefully at the brightest stars. Some should look slightly red and others slightly blue. The primary factor that determines the color of a star is its temperature. Which is hotter: a blue star or a red one? Explain
2. Water faucets are often labeled with a red dot for hot water and a blue dot for cold. Given Wien’s law, does this labeling make sense? See figure below

1. If the answer to this (What is 0628-28 spin period in seconds while keeping frequency at 1000.00MHz?) is 1.26. What is the answer to What is 0628-28 spin period in seconds while keeping frequency at 600.00MHz?
2. What is the distance in parsec to pulsar 0628-28 using 400 and 600 MHz frequencies? Use the last equation on page 14 of the Instructions.pdf manual.
Equation on page 14 is attached.

Overview of Paper 1: Representative Bill Flores is meeting with a high school class in Waco to talk about science. He needs a short and sweet descriiption of “The evidence for dark matter.” He has asked his Chief of Staff to help him prepare for his presentation.
The Assignment: You are working in the Chief of Staff’s office as a summer intern. The Representative is going to a hearing from a prominent cosmologist later and wants to know basic information about Dark Matter beforehand. Because you have taken a course that discusses this question, you are tasked with this assignment. Your job is to create a “short and sweet” paper that summarizes and explains the reasons/evidence for dark matter in plain language so that both the Chief of Staff and the representative can understand them. Said differently, based on your report, both need to be able to answer this important question quickly and intelligently.
Big Picture of how your paper should be organized (Note: This portion is identical for all assignments):
• Your document needs to include the important pieces of evidence, follow the above and below instructions about what structure it needs to be in as well as include the things we are explicitly requiring for this paper (see below). You will be graded on your ability to do it all.
• Your introduction must make it clear what it is really about (in this case providing the evidence for dark matter), mention the evidence/talking points to be discussed as well as outline the argument that will be used in the paper.
• The paper must be clear and concise, with a proper essay format. It should be between 400-750 words, although you are allowed to make it longer, more is unlikely to be short and sweet. While it needs to touch on the major “big picture” issues and use plain language, it obviously can’t go into too much detail on any one topic.
• It must have proper paragraph structure including topic sentences for each paragraph.
• Use only language that can be understood by a lay-person who has NOT taken the class (no buzz words!).
• It must be easy to read.
• You may choose the number of pieces of evidence (and number of evidence/talking point paragraphs), but this is NOT an independent research project. You are to use only evidence explained in this chapter( https://he.kendallhunt.com/sites/default/files/heupload/pdfs/Toback_1e_Ch6.pdf). You should not assume you need to have three and only three pieces of evidence nor do you need three and only three evidence paragraphs. While you may choose your number of evidence paragraphs, the typical writer will choose one paragraph per piece of evidence. Additional paragraphs may be used to explain any physics concepts that are required to understand the evidence as long as you stay on-topic.
• It must also have a conclusion paragraph that ties the pieces of evidence/talking points together and wraps up the argument. It should be like the closing argument from a lawyer. If you just restate the evidence, that isn’t a conclusion/summary arugement.
Some additional comments particular to this assignment (including some, but not all, of what you WILL need to do in the paper):
• If you are going to use words or phrases like “dark matter” you need to explain them clearly.
• You need to clearly describe some of the aspects of gravity and how objects orbit around each other due to the attraction of gravity. Note: This is NOT a paper about the difference between Newton and Einstein, or their theories. This is not about a proof of General Relativity. It is about Dark Matter and the evidence for it. You may assume that General Relativity is correct, but you cannot assume that your reader knows anything about it. You do not need to use the phrase General Relativity explicitly.
• Since this is NOT a paper about Einstein’s version of gravity vs. Newton’s, nor the history, neither a descriiption of the people or history are needed. Indeed they should be avoided as they will take away from the “short and sweet” nature of the paper and the main point, which is about evidence for dark matter.
• You need to clearly describe how planets orbit the Sun as evidence for our understanding of gravity.
• You need to clearly describe how stars orbit in the outer reaches of galaxies and how this provides evidence.
• You need to clearly describe how the lensing of galaxies provides evidence.
• While you may choose your number of body paragraphs, the typical writer will choose one paragraph per piece of evidence; you could also include a setup paragraph explaining any physics that will be relevant to later evidence paragraphs.
• Note: The above is not THE evidence, but is part of what you need to help describe the evidence. Said differently, if you do NOT have those things, you have not provided the evidence

sing the HR diagram provided in this module (download the JPG file), find the absolute magnitudes for seven Main Sequence stars of temperatures 25000 K, 10000 K, 8000 K, 6000 K, 5000 K, 4000 K, 3000 K.
As explained in the video, find the Kelvin temperature, for a given star, on the horizontal upper axis, then move down from that point to the Main Sequence, then move right to the vertical absolute magnitude axis and read off the absolute magnitude.
Make a table with two columns. Kelvin temperature on the left and absolute magnitude on the right. Seven stars.
You will use these temperatures and absolute magnitudes in the next project, to find the distances to stars of certain apparent magnitudes that I will assign. Apparent magnitude is a measure of the amount of a star’s light that enters the telescope. The absolute magnitude is a measure of the total power radiated by a star in all directions.

Recall that a spectroscope spreads out light into its component colors, or WAVELENGTHS. A laser pointer emits light at just one wavelength. A light bulb emits a mix of countless wavelengths. A spectroscope spreads them out so you can see the colors, or wavelengths, separately.
Let the light from the source shine in through the vertical slit in the spectroscope. Concentrate on seeing the light come through the vertical slit first, then move your eyes to the left or right to see the colorful spectrum. It takes some practice to produce a nice rainbow, or spectrum. For example, the Sun delivers way more light than you need, but the Moon’s spectrum is tough to see because the Moon is much fainter than the Sun and only a narrow slit allows the light through. You will be able to see rainbows on the left and right, and even on top of the wavelength scale, depending on how you hold the spectroscope.
Sources with a small angular size in your field of view (like a pen light, candle flame, the Sun,) produce the best spectra. Big sources like a TV screen or your roof on fire will be difficult: There will be fat, overlapping spectra.
Try observing the Sun, an incandescent light bulb, an LED light, a fluorescent light, a candle flame, gas flame from stove or propane torch, streetlight, red light from electric stove coil. When you observe the Sun, do not put the slit directly on the Sun. It is too bright. Protect your eyes by putting the slit near the Sun, but not directly on it. Keep the Sun just out of the slit. You will still get plenty of light and a bright spectrum. Pay attention to the dark absorption lines you see against the Sun’s spectrum (rainbow). Draw them in on your diagram.
Draw me a picture of your observations of six light sources. Make it look like a long bar, with sections showing the different colors. One bar for each spectrum/light source observed. Use colored pencils. Label the parts of the spectrum indicating colors and brightnesses. Send me a photo or scan of your picture.
Make comments on what you’ve seen. You will need them for your report in the next project. For example, “I was surprised how little yellow light I saw in the spectrum of a candle flame. There definitely wasn’t much blue, but there was a lot of RED.”
I expect you to draw me at least SIX SPECTRA (rainbows). Be a careful observer and recorder. Don’t just make a kindergarten mess with your crayons. I know what these spectra are supposed to look like, so pay attention. This is easy points if you follow instructions the first time. Many of your predecessors did not and brought great pain upon themselves.

A large part of astronomy is making observations, even with the naked eye. To that end, you will be keeping an observation log throughout the term. To that end, you will be keeping an “observing log” where you will take weekly observations using online resources and hopefully the clear sky! You will be recording a log of the sky and making observations of what you see. Below I will attach a link with complete directions and the whole format and template you will be using. You will need to fill out week #4. It is from the perspective of someone living in Salem Oregon on the days between January 29-feb 4, 2024. I will also post a screenshot to show you how it should look.
https://docs.google.com/document/d/1vvEOG2cTk6YGpvQ_fObDjsllD9ZoZBUmPNclREi-ceE/edit

sing the HR diagram provided in this module (download the JPG file), find the absolute magnitudes for seven Main Sequence stars of temperatures 25000 K, 10000 K, 8000 K, 6000 K, 5000 K, 4000 K, 3000 K.
As explained in the video, find the Kelvin temperature, for a given star, on the horizontal upper axis, then move down from that point to the Main Sequence, then move right to the vertical absolute magnitude axis and read off the absolute magnitude.
Make a table with two columns. Kelvin temperature on the left and absolute magnitude on the right. Seven stars.
You will use these temperatures and absolute magnitudes in the next project, to find the distances to stars of certain apparent magnitudes that I will assign. Apparent magnitude is a measure of the amount of a star’s light that enters the telescope. The absolute magnitude is a measure of the total power radiated by a star in all directions.

Recall that a spectroscope spreads out light into its component colors, or WAVELENGTHS. A laser pointer emits light at just one wavelength. A light bulb emits a mix of countless wavelengths. A spectroscope spreads them out so you can see the colors, or wavelengths, separately.
Let the light from the source shine in through the vertical slit in the spectroscope. Concentrate on seeing the light come through the vertical slit first, then move your eyes to the left or right to see the colorful spectrum. It takes some practice to produce a nice rainbow, or spectrum. For example, the Sun delivers way more light than you need, but the Moon’s spectrum is tough to see because the Moon is much fainter than the Sun and only a narrow slit allows the light through. You will be able to see rainbows on the left and right, and even on top of the wavelength scale, depending on how you hold the spectroscope.
Sources with a small angular size in your field of view (like a pen light, candle flame, the Sun,) produce the best spectra. Big sources like a TV screen or your roof on fire will be difficult: There will be fat, overlapping spectra.
Try observing the Sun, an incandescent light bulb, an LED light, a fluorescent light, a candle flame, gas flame from stove or propane torch, streetlight, red light from electric stove coil. When you observe the Sun, do not put the slit directly on the Sun. It is too bright. Protect your eyes by putting the slit near the Sun, but not directly on it. Keep the Sun just out of the slit. You will still get plenty of light and a bright spectrum. Pay attention to the dark absorption lines you see against the Sun’s spectrum (rainbow). Draw them in on your diagram.
Draw me a picture of your observations of six light sources. Make it look like a long bar, with sections showing the different colors. One bar for each spectrum/light source observed. Use colored pencils. Label the parts of the spectrum indicating colors and brightnesses. Send me a photo or scan of your picture.
Make comments on what you’ve seen. You will need them for your report in the next project. For example, “I was surprised how little yellow light I saw in the spectrum of a candle flame. There definitely wasn’t much blue, but there was a lot of RED.”
I expect you to draw me at least SIX SPECTRA (rainbows). Be a careful observer and recorder. Don’t just make a kindergarten mess with your crayons. I know what these spectra are supposed to look like, so pay attention. This is easy points if you follow instructions the first time. Many of your predecessors did not and brought great pain upon themselves.

To view and identify the main features of the Moon, including craters and maria AND DRAW THEM
NO MORE THAN 1 PAGE!

Instructions: Watch the videos & fill in the blanks.
Some videos will be watched in class and some will need completed at home on your own time.