Star Spectra Gizmo Answers

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Star Spectra is one of the science materials you can find on Gizmo. It talks about the interior of a star that produces a continuous spectrum of light like a rainbow. The cooler gases in the outer layers of the star actually absorb certain wavelengths of light, causing dark lines to appear in the spectrum.

After learning about Star Spectra, you will be able to take the Star Spectra test on Gizmo. Certainly, you may have to answer all the questions correctly. If you are accidentally looking for Star Spectra answers, you can dive into our post since we will show them for you below. Here you go!

Star Spectra Gizmo Answers

There are three sections on Star Spectra test including Warming Up, Activity A and Activity B. In this post, we will show you the correct answers to Star Spectra for Activity A and B that we got from StuDocu. We will show the correct answers to Star Spectra highlighted in bold font.

Prior Knowledge Questions

  1. What happens when light goes through a prism? The white light separates into different wavelengths and colours like red, orange, green, yellow, and other colors.
    This band of colors is called a Spectrum.
  2. A rainbow is an example of a spectrum. What is the sequence of colors in a rainbow?
    The dark line represents the absence of light. The colours go red, green, yellow, orange, purple, blue and black lines are spread throughout.

Here are they:

Warming Up

Star Spectra Gizmo Answers-Gizmo Warm-up

  1. On the Star Spectra Gizmo, turn on Show labels. Select star 1to see its absorption spectrum.
    How many lines do you see in the spectrum? 10 lines
  2. Drag the Hydrogen spectrum next to the Star spectrum so that the edges line up.
    Do some of the lines on the two spectra match up? Yes some of them do, some don’t
  3. Drag the Helium spectrum next to the Star spectrum. Do some lines match? Helium does line up with the star spectrum
  4. Try out the other available spectra. Do any others have lines that match? No, none others do.
  5. Which elements have contributed to the spectrum of star 1? Helium and Hydrogen

Activity A – Classifying Stars

Question: How are stars classified?

Introduction: Late in the 19th century, Harvard astronomer Edward Pickering wanted to sort and catalog the thousands of star spectra that had been collected by the Harvard Observatory. He hired several women to do the work, paying them 25 cents a day. The most prominent of these women was Annie Jump Cannon, who devised a classification system still used today.

Harvard Classification Scheme
Class Color Prominent Spectral Lines Surface Temp. (K)
O Blue Ionized Helium, Hydrogen >25,000
B Blue-White Neutral Helium, Hydrogen 11,000 – 25,000
A White Hydrogen, Ionized sodium, ionized calcium 7,500 – 11,000
F White Hydrogen, ionized sodium and calcium: neutral sodium and calcium 6,000 – 7,500
G Yellow Neutral sodium and calcium, ionized calcium, ionized iron, ionized magnesium 5,000 – 6,000
K Orange Neutral calcium, neutral iron, neutral magnesium 3,500 – 5,000
M Red Neutral iron, neutral magnesium and neutral titanium oxide <3,5000
  1.  Classify: Use the Gizmo to find the elements that are present in the spectra of stars 1 through 4. Remember to check both the Neutral spectra and the Ionic spectra. Then use the table above to classify each star and describe its surface temperature.
Star Color Elements in Spectrum Class Surface Temperature (K)
1 Blue Ionized Hydrogen, Ionized Helium O >25,000
2 Orange Neutral Calcium, Neutral Iron, Neutral Magnesium K 3,500 – 5,000
3 Blue Ionized Hydrogen, Ionized Helium O >25,000
4 White Hydrogen, Ionized sodium, ionized calcium A 7,500 – 11,000
  1. On your own: Look up Annie Jump Cannon on the Internet or in a library and read her story. Share your discoveries with your classmates and teacher.

Annie Jump Cannon was an American astronomer whose cataloging work was instrumental in the development of contemporary stellar classification.

Activity B – Unusual Stars

Question: What else can we learn from stellar spectra?

  1.  Observe: Observe the spectra of stars 5 – 10. Identify the elements in each spectrum, and try to classify each star. If you notice unusual features in these spectra, describe them.
Star Color Elements in Spectrum Class Unusual Features
5 Yellow None of the elements match G Has de double line like in sodium, but they are shifted
6 Red Neutral iron and neutral titanium oxide M Neutral magnesium does not fit, it has certain black lines more run than the original magnesium
7 Blue-White Neutral helium, hydrogen B Normal
8 Yellow Neutral sodium and calcium G Some dark lines in Neutral sodium are stranger and the light flicker, go up and down
9 White Hydrogen, Neutral Sodium, ionized calcium F Calcium did not match neither ionized or neutral, besides moving sometimes
10 Yellow Neutral sodium and calcium G Normal

Match: Write the number of the star or object that matches each description. Then use this information to help you identify the elements and reclassify the stars in the table above.

3 High atmospheric pressures in a star cause spectral lines to be broadened, or “smeared out.” Giant stars, which have relatively low atmospheric pressures, are characterized by narrow spectral lines.
2 If a star is moving away from an observer, spectral lines are redshifted, or shifted toward the red end of the spectrum. An approaching star is blue shifted
8 A star orbited by a large planet will move in a small circle. This will cause its spectrum to be slightly red shifted part of the time and blue shifted at other times.
4 Binary stars are pairs of stars that orbit one another. Their presence is indicated by two spectra that shift in opposite directions.
6 Cepheid variable stars change their brightness in a regular cycle. Gas pressure builds up, causing the stars to expand quickly. When the pressure is released, the star contracts, and the intensity of some spectral lines may decrease.
7 nebula is an enormous cloud of gas and dust in which stars are born. Most nebulae produce an emission spectrum, which is characterized by bright lines of color against a dark background. The bright lines in an emission spectrum correspond to the dark lines in an absorption spectrum.

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