SPACETRC / OPEN LEARNING LAB
Astronomy Foundations
Investigate a scientific question through light, spectra, transits and observation records.
A lesson is recorded as practised when its answer is correct and you have written a reflection of at least 20 characters. This checks participation and basic understanding; it is not a qualification or accredited certificate.
Before you begin 3 questions
LEARNING OBJECTIVE
Use light as a measure
Distinguish distance from light-travel time.
An image reaches us after light has travelled. Distance and travel time are different quantities; compare them only after keeping the units consistent.
This exercise assumes a constant distance and the speed of light in vacuum. The actual distance between Earth and a spacecraft may change.
t = d / cModel example: a 300,000 km distance / 300,000 km/s speed = 1 s. These rounded inputs illustrate the relationship only.
LEARNING OBJECTIVE
Measure a spectral shift
Calculate a dimensionless shift from wavelengths.
Compare a spectral line’s laboratory and observed wavelengths. Interpreting the shift depends on its physical context.
Here we calculate only z. It is not automatically a distance or a velocity valid in every regime. The line must first be identified correctly.
z = (λobs − λrest) / λrestTeaching inputs: 500 nm → 505 nm. z = (505 − 500)/500 = 0.01. Both wavelengths use the same unit.
LEARNING OBJECTIVE
Read a transit light curve
Separate a measured dip from a simple radius model.
A transit may cause a dip as an object passes between the observer and a star. Other effects can also produce a single decrease.
For a uniformly bright stellar disc and a small dark planet, depth is approximately the square of the radius ratio. Limb darkening and noise affect real analysis.
δ = 1 − Fin/Fout; Rp/Rs ≈ √δIf normalized flux falls from 1.00 to 0.99, the model depth is 0.01. In the simple model, Rp/Rs ≈ √0.01 = 0.10.
LEARNING OBJECTIVE
Preserve observation provenance
Record a dataset’s time, instrument and processing.
A graph becomes interpretable with its source and processing steps. Observation and download dates may differ.
Recording product identifier, time system, unit, quality flag and processing version lets another person inspect the same selection.
Gözlem ≠ erişim ≠ işleme / Observation ≠ retrieval ≠ processingKeep observation time, retrieval time and product identifier in separate fields instead of reporting only “downloaded on 24 October”.
Check your learning 3 questions
The same short self-check before and after practice helps you review what changed. It does not measure expertise independently.
Turn practice into a research report.
Write a question, record your inputs, compare results and discuss uncertainty.
Start this projectYOUR WORK / YOUR COPY
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Study pack: release 4.0.0 · content dated 24 October 2026 · self-contained lessons, exercises, project templates and source-labelled sample data. Unzip and open index.html. No external API is required.