Plot the light curve
See this course’s project requirements
A small exoplanet-signal investigation with a graph, depth and period calculations, a NASA archive comparison and an evidence-based report.
Keep your working files in your own notebook or software. Save a private description, checklist, and work link in My Proof.
What to include
- A provenance note that clearly labels the synthetic fixture.
- A 20-point XY chart with correct time and relative-flux labels.
- Checked baseline, depth, radius-ratio approximation and period calculations.
- A comparison of detected signals, candidates and archive records.
- Input CSV, working calculations, graph and short report with limits.
Review and revise
Use these criteria to check your work and choose what to improve.
- The plotted values and units agree with the fixture.
- The calculations can be reproduced from stated inputs.
- Synthetic, observed and predicted information are distinguished.
- The conclusion stays within the supplied evidence.
Want more background?
The idea in everyday life
Open the supplied CSV in LibreOffice Calc using comma separation. Row 1 is the header; rows 2–21 are 20 measurements. If starting without the file, paste the same table at A1.
An XY plot positions points by their numeric times; a category chart can hide uneven sampling.
Plot the light curve — guided practice
Use numeric time spacing to display the pattern accurately.
Open the supplied CSV in LibreOffice Calc using comma separation. Row 1 is the header; rows 2–21 are 20 measurements. If starting without the file, paste the same table at A1.
Original synthetic light curve
Paste at A1.
| Atime_days | Brelative_flux |
|---|---|
| 0 | 1.001 |
| 0.25 | 0.999 |
| 0.5 | 1 |
| 0.75 | 0.995 |
| 1 | 0.99 |
| 1.25 | 0.995 |
| 1.5 | 1 |
| 2 | 1.001 |
| 3 | 0.999 |
| 3.75 | 0.995 |
| 4 | 0.99 |
| 4.25 | 0.995 |
| 4.5 | 1 |
| 5 | 1.001 |
| 6 | 0.999 |
| 6.75 | 0.995 |
| 7 | 0.99 |
| 7.25 | 0.995 |
| 7.5 | 1 |
| 8 | 1 |
Copy as plain text
1. Import and preserve
Open transit-practice.csv and choose comma as separator. Confirm two numeric columns. Save As transit-investigation.ods so charts and formulas can be preserved.
You should see: A1:B21 contains labeled numeric time and flux data.
Native spreadsheet saving keeps more than a CSV’s plain values.
2. Insert a numeric-time chart
Select A1:B21. Choose Insert > Chart, then XY(Scatter) and Points Only or Points and Lines. Use data series in columns and first row as label. Confirm column A supplies X and column B supplies Y.
You should see: The plot uses the unequal time gaps correctly.
A standard category line chart can place unequally spaced observations at equal distances.
3. Label the evidence
Set title: Synthetic transit practice. X-axis: Time(days). Y-axis: Relative flux. If needed, double-click the Y-axis and set its Scale minimum 0.985 and maximum 1.005 to inspect the small dips.
You should see: Three low groups near days 1, 4, 7 are visible on a clearly labeled zoomed axis.
A zoomed axis helps inspection but must remain labeled so the dip size is not exaggerated silently.
4. Read the pattern
Record the lowest plotted value 0.990 and the three approximate centers 1, 4, 7. Note that connecting lines would only guide the eye between samples; they are not extra observations. Save.
You should see: The chart suggests a recurring pattern with gaps in sampling.
A graph should not imply measurement at times that were never sampled.
What to finish
A labeled XY chart in an ODS workbook.
Watch for this
Using equally spaced category positions for uneven times.
How can I tell I understand it?
Explain the result, reproduce the procedure, and complete the changed-input check.
Quick knowledge check
Answer all 3 questions. Get at least 2 right and the lesson completes automatically.
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Pass the check. We’ll save the progress.
Answer all 3 questions above and get at least 2 right. You can review the explanations and try again.
Go to the knowledge checkOptional course overview video · same video as Lesson 1
NASA | Alien Atmospheres
From NASA Goddard. Watch here or open it on YouTube .
Optional course overview. Follow the written steps below at your own pace.Tools, templates, and lesson sources
Tools and templates
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Sources and further reading
Explore the references behind this lesson.
Source & access notes · checked 2026-09-12
Read transit, radial-velocity and spectroscopy explanations; course makes no current planet-count claim.
Access: Public reading without a paid account; reviewed September 12, 2026.
Reuse: Link only. Lessons and practice assets are original; free access does not grant permission to copy the provider's material.
Source & access notes · checked 2026-09-12
Read primary visualization description of planetary transit and brightness changes; animations linked, not copied.
Access: Public reading without a paid account; reviewed September 12, 2026.
Reuse: Link only. Lessons and practice assets are original; free access does not grant permission to copy the provider's material.
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