The Nighttime Sky

 Introduction to Scientific Inquiry

Big Idea: The night sky can present many patterns and rhythms to the astronomer. In pre-technological times, everyone was aware of the nighttime sky. We can share the beauty of the star-filled night sky with family and friends.

Use Uncle Al’s Star Wheel with RA and Dec noted on sky map with equitorial grid

Goal: Students will conduct a series of inquiries about the night sky using a “Star Wheel” constructed in Lab. We will use “Scientific Inquiry” to consider the times and positions of rising and setting stars, as well as learn constellations and the equatorial co-ordinate system.


Phase I: Star Wheel Construction                                                             (25 points)

Use the template and file folders to construct your own Star Wheel. Carefully follow instructions. Cut on bold solid lines, fold on the dashed lines. Put your name on your Star Wheel and have you instructor check it. Neatness counts. Exactness counts.

Use your Star Wheel to complete this lab report.

Phase II: Exploration and Writing a Conclusion      (20 points)

With your Star Wheel neatly and correctly constructed, insert the wheel into the pocket so you see the unlined sky and the wheel turns smoothly.

Align the date August 25 on the disk with the time 8 pm on the pocket.

The sizes and shapes of the marks on the star wheel represent the brightness of the stars. Dimmer stars are represented by a small dot, and the brightest stars by larger marks with points. An object rises if it is below the horizon, then moves above the horizon. Setting objects begin above the horizon and then move to below the horizon.

Find Spica, the brightest star in the constellation Virgo, and note its location. Smoothly and carefully turn the wheel in the pocket so August 25 is lined-up with 9 pm. This models the movement of the stars during one hour.

  1. From 8 pm to 9 pm on August 25, Spica…            (circle all that apply)
  2. rises in the east    b. arcs across the sky             c. sets in the west


Reset your Star Wheel to 8 pm August 25. Find Altair, the brightest star in Aquila. Turn the wheel and observe Altair’s movement

  1. From 8 pm to 5 pm Altair…                 (circle all that are true.)
  2. rises in the east           b. stays n the same location   c. sets in the west




Reset your Star Wheel to 8 pm August 25. Find Deneb, the brightest star in Cygnus. Turn the wheel and observe Cygnus’s movement.

  1. From 8 pm to 5 am the next day, Deneb…          (circle all that are true.)
  2. rises in the east    b. stays in the same location     c. sets in the west

Question: What is the pattern on movement of stars in our sky?

Write a paragraph (5-7 sentences) that answers this question.

  1. Write 1-2 complete and developed sentences that clearly answer the question.




  1. Write 2-3 complete and developed sentences that give observable facts from your Star Wheel supporting your answer. Be specific.

EX: Altair sets further north along the eastern horizon than does Spica.




  1. Write 1-2 complete and sentences that describe weakness in this research.

EX: We don’t know how far away these stars are from Earth.




  1. Write 1-2 complete and developed sentences that pose a deeper question.

EX: Do these brighter stars just appear brighter because they’re closer?



PHASE III – Analyzing Data and Writing a Conclusion (20 points)

The equatorial co-ordinate system describes the position of an object relative to the celestial equator, the great circle on the celestial sphere that lies directly above the Earth’s equator. An object on the celestial equator would have a declination of 0o 00’

Right Ascension, sometimes called the hour angle, is the equivelant of longitude on Earth but measured in hours and minutes. The point in the sky where the path of the ascending Sun crosses the celestial equator is 0hr 00 min.

Table 1 describes the position of the Sun using the equatorial co-ordinate system. of the Sun. Use the side of the wheel with the concentric circles printed.

With a pencil, lightly draw a dot on the wheel where the Sun is located in the sky each date. The still with pencil, lightly draw in a best-fit curve that will connect the dots in order. This path of connected dots is the ecliptic, the apparent path of the Sun against the background stars.

  1. Write in the name of the constellation for each date.
TABLE 1:   Position of the Sun in the sky
Date (2017-8) Number of days from previous Right Ascension

(Hour Angle)

Declination Constellation
Mar 20   0 hr 00 min + 0o 04’  
Apr 19 30 1 hr 50 min + 11o 22’  
May 20 31 3 hr 50 min + 20o 06’  
Jun 19 30 5 hr 53 min + 23o 26’  
Jul 20 31 8 hr 00 min + 20o 33’  
Aug 19 30 9 hr 56 min + 12o 35’  
Sep 19 31 11 hr 48 min + 1o 15’  
Oct 19 30 13 hr 37min – 10o 11’  
Nov 19 31 15 hr 41min – 19o 36’  
Dec 19 30 17 hr 51min – 23o 25’  
Jan 19 31 20 hr 07 min – 20o 15’  
Feb 18 30 22 hr 05 min – 11o 30’  
Mar 20 31 24 hr 01 min – 0o 01’  


  1. What is your astrological “sign”?                           ___________________________________

Calculate where on the ecliptic you will find the Sun on your birthday and make a special light pencil mark there on the wheel.

  1. The Sun will be in what constellation on your birthday? _____________________________



Find two classmates and their birthdays, Research to find their sign, their sun-sign for horoscope purposes. Then use your Star Wheel to determine the constellation the Sun is actually in on their birthdays.

Classmate’s name               Birth date           ‘Sun-sign”                 actual location


  1. Write an evidence-based conclusion following the format in Phase III to the Question:

Is the horoscope “sun-sign” accurate?





























PHASE IV: Collecting Data and Writing a Conclusion    (25 points)

TABLE 2:   Movement of the Sun through the constellations
Date (2017-8) Right Ascension

(Hour Angle)


Deg, min

Distance from the last position

(straight iine, in mm)

Mar 20 0 hr 00 min + 0o 04’  
Apr 19 1 hr 50 min + 11o 22’  
May 20 3 hr 50 min + 20o 06’  
Jun 19 5 hr 53 min + 23o 26’  
Jul 20 8 hr 00 min + 20o 33’  
Aug 19 9 hr 56 min + 12o 35’  
Sep 19 11 hr 48 min + 1o 15’  
Oct 19 13 hr 37min – 10o 11’  
Nov 19 15 hr 41min – 19o 36’  
Dec 19 17 hr 51min – 23o 25’  
Jan 19 20 hr 07 min – 20o 15’  
Feb 18 22 hr 05 min – 11o 30’  
Mar 20 24 hr 01 min – 0o 01’  


  1. Measure the distances between your pencil dots indicating solar position. Complete the last column of Table 2.










Does the Sun appear to move at a steady pace through the constellations?

  1. Write an evidence-based conclusion.
















PHASE V: EXTRA CREDIT: Collecting Data   (up to 10 points)

The planets generally follow the path of the Sun, never too far above or below the ecliptic. Constellations that include the ecliptic are called zodiac constellations, and they often contain planets. If you see a bright star in a zodiac constellation that doesn’t belong, you’ve found a planet!

Safely observe the night sky. (Be with someone in a familiar place.) Using your star wheel, face the southern sky and find the constellations both on your Sky Wheel and in the sky.


  1. Date: _________________ Time: __________________


  1. One bright object found in sky not on Star Wheel: RA ________ Dec _________


  1. Date: _________________ Time: __________________


  1. One bright object found in sky not on Star Wheel: RA ________ Dec _________


  1. If you have binoculars, take a look at one or both. What do you see?
















Phase VI – Summary and Reflection            (10 points)

Create a summary in your own words (at least 75 words, but not much more than 150 words) that describes the movement of celestial objects in the sky. Describe the main concepts you learned in this lab. Feel free to create and label sketches to illustrate your response. Describe what you learned in this Lab.


Successful Inquiry

  1. Specific Research Question: One question clearly stated.
    1. This should be an imaginative question that requires the measurement of something to discover a pattern.
    2. Evidence in the form of numbers is needed to analyze, synthesize or compare. The best questions are not such that you could look up the answer, but an inquiry of depth, about an interesting topic.
  • GOOD EXAMPLE: ”How does the time of sunset change over the course of a year at this location?”
  • POOR EXAMPLE: “When does the Sun set on September 25?”


  1. Step-by-Step Procedure to Collect Evidence: Create a plausible method for collecting and organizing data.
    1. The data collected should be numbers, measuring different aspects of the situation described in the question.
    2. Procedure should be clearly described so another scientist could repeat the observations.
    3. Plan the structure you will impose on the data. Usually this begins with a table. Be ready and willing to add to and adjust your plans as you collect data.   You might have to retrace your steps.


  1. Results and Data Table: A table that organizes the numbers is one simple, traditional way to present data collected.
    1. Data should be specific and exact. Don’t be afraid of decimals.
    2. Measurements (numbers) might describe changes to important factors or present a way of seeing similarities or differences in various factors. Numbers can be used for comparisons and analysis.
    3. Neatly organize the numbers in the table you planned in 2. above. Include a title for the table and titles for each column.
    4. Having more than one variable suggests that a graph might be useful. Your graph would compare and contrast the data collected.   Choose a scale for the graph that gives a clearer picture of the comparison.


  1. Evidence-based Conclusion Statement: This is a multi-sentence conclusion that includes facts and numbers from the collected data, and uses logic to explain the pattern of those numbers.
    1. Be explicit about the data, using at least one example to illustrate how the logical process was carried out. Your reasoning should make some sense of the numbers, telling what they mean.
    2. Be careful stating what the data supports and doesn’t support. Use your words wisely. Defend your interpretation of the data.
    3. Acknowledge weaknesses. All research has weaknesses because all models are wrong. Clearly describe any problems or uncertainties.
    4. Raise a “deeper question” that might warrant more research. A deeper question may be one that is not readily found answered elsewhere, one that makes one wonder if one or some of their preconceptions are wrong, or gives a profound insight into understanding the universe.   (This is possibly the most difficult expectation.)

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