De-Coding Starlight: From Pixels to Images - Middle School

Student Handout

The Scenario

You and your partner have just discovered a brilliant new supernova remnant using the Chandra X-ray Observatory. The Director of NASA Deep Space Research has heard of your discovery and wants a report of your results in her office in 45 minutes. Unfortunately, your computer crashed fatally while you were creating an awesome image of the supernova remnant from the numerical data. Because the NASA director always wants to see cool images (not numbers) of newly discovered objects, you and your partner will have to create, by hand, an image of the supernova remnant.

To create the image, you and your partner will have to use "raw" data processed from the Chandra satellite. You have tables of the data, but during the excitement of the computer crash, you spilled soda over some of the information and will have to recalculate some values.

In addition to the graph, you and your partner will have to prepare a written explanation of your discovery and answer a few of the Director's questions.

Your Tasks

Before you are ready to present your findings to the NASA director, you will need to complete the following three tasks.

Task A: Calculations

1. Your mission is to turn "boring" numbers into a super-cool picture. Before you can make the image, you will need to make some calculations.
2. The raw data for the destroyed "pixels" (grid squares containing a value and color) are listed in Table 1. Before making the image, you will need to fill in the last column of Table 1 by calculating average X-ray intensity for each pixel.
3. After you have determined average pixel values for the destroyed pixels, write the numerical values in the proper box (pixel) of the attached grid. Many of the pixel values are already on the grid, but you have to fill in the blank pixels. This is the grid in which you and your partner will draw the image.

Task B: Coloring the Image

You and your partner will need to complete the following steps in coloring the image. Important Note: Read all the instructions carefully before you start coloring!

1. You are allowed to use five and only five colors in drawing your image.
2. Using colored pencils, shade in the grid using the color legend. Match the value in the grid to the color range shown on the legend and color the grid squares according to the legend.

Task C: Preparing the Presentation

1. Draw an picture of what the actual supernova remnant would "look" like. In your drawing, include and label the neutron star, a fast outer shock wave, and a slower inner shock wave.
2. The NASA director has the following specific questions about your findings. Answer these questions on the back of the image.
   1. In the table, some of the data were missing. In 2-3 sentences, describe how you "handled" these missing data in making your calculations and coloring your image.
   2. Because your computer crashed, you had to draw the image by hand. In 2-3 sentences, explain why would it have been easier to use a computer? (In your answer, consider that the Chandra satellite actually sends millions of data from each observation and how long it would take to process millions of data by hand.)

Table 1. "Raw" data of the newly discovered supernova remnant collected from the Chandra X-ray Observatory.

Missing Grid Coordinate	Number of X-ray Photons Detected					Average Number of Photons
	Observation 1	Observation 2	Observation 3	Observation 4	Observation 5
C3	50	54	52	50	54
E8	214	210	210	210	214
F6	148	135	missing	missing	130
H10	73	83	missing	80	81
I5	58	69	54	missing	65

Supernova Remnant Image Grid

	A	B	C	D	E	F	G	H	I	J	K
1	0	1	1	1	1	1	1	1	1	1	1
2	2	5	35	42	48	48	50	51	46	18	7
3	23	36		35	30	27	21	31	38	13	0
4	41	43	24	8	216	155	126	120	54	21	3
5	36	58	37	44	36	20	33	105		23	4
6	32	60	34	106	12		18	96	24	50	17
7	24	65	32	141	41	17	12	126	64	67	21
8	18	69	36	237		146	155	114	22	74	6
9	16	75	38	34	26	12	14	21	77	37	4
10	8	71	63	54	42	23	64		31	16	2
11	3	3	2	1	0	0	2	0	1	0	0

Legend

Average number of photons	< 40	40-80	81-120	121-160	>160
Color