Trace massive stars through supernova and compact remnants
Follow a red supergiant through supernova into enriched material and a neutron star or black hole.
Section 6.2.2 · Stars
Exam scope and assessment notes
Extended only (Supplement) · Physics 0972, 2026–2028. Use supplied distances, periods and stated orbital models. Drawings are not to scale. Written practice is self-checked. Human subject-teacher review, supervised practical competence and cumulative assessment remain pending. Cambridge states that IGCSE 0972 has the same subject content as IGCSE 0625, with 9–1 grading. This StudyForA pathway maps the 2026–2028 syllabus only. This 9–1 graded qualification is available only in a limited number of administrative zones. Confirm that your centre can enter you for this code and exam series with Cambridge International. Cambridge has published a separate syllabus for 2029. StudyForA has not reconciled that version yet; this page supports exams in 2026, 2027 and 2028 only.
Before you begin
- Recall the more-massive branch.
- Distinguish an event from a resulting object.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
Which giant belongs to the more-massive syllabus branch?
What you will learn
- Follow a red supergiant through supernova into enriched material and a neutron star or black hole.
- Separate the explosion, expelled nebula and alternative central remnants.
Track two products of the event
The syllabus’s more-massive branch follows a red supergiant into a supernova explosion. Expelled material forms a nebula containing hydrogen and newly produced heavier elements. A compact remnant remains at the centre: a neutron star or a black hole, depending on the evolved core and its outcome.
The supernova is the event, not a permanent star class that subsequently must turn into both remnants. The expelled cloud and compact centre must be labelled separately. A branch ending neutron star OR black hole describes alternatives, not a compulsory neutron-star-then-black-hole sequence for every example.
Avoid unsupported endpoint claims
Initial stellar mass is relevant to evolution, but a picture’s apparent brightness does not supply all the information required to predict a remnant. This course uses the broad syllabus branches; it does not prescribe one universal sharp mass threshold from a supplied uncalibrated image.
The expelled material enriches later interstellar clouds. It contains hydrogen as well as heavier elements; it is not only solid iron and not all swallowed by the central remnant. Some later clouds may form new stars and planets, which the next lesson follows.
Pause and explain
What can remain at the centre after a massive-star supernova?
Worked example
A massive star’s supernova diagram has an extended cloud and a compact centre. Give the labels and alternatives.
Show the worked solution
- Name the event as supernova.
- Identify a nebula containing hydrogen and heavier elements.
- Allow neutron star or black hole as the central remnant.
Answer Enriched nebula; central neutron star or black hole.
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
Write the more-massive route from stable star through the endpoint.
Give me a hint
Include the event, cloud and alternative compact centre.
Compare my reasoning
- Stable star expands to a red supergiant.
- A supernova expels an enriched nebula.
- The centre retains a neutron star or black hole.
Stable massive star → red supergiant → supernova, enriched nebula and neutron star or black hole.
Look for these in your work
- Name the explosion.
- Separate cloud from remnant.
Correct “all expelled supernova material is only helium and the centre is always a neutron star”.
Give me a hint
Both material composition and the remnant alternatives need correction.
Compare my reasoning
- The nebula includes hydrogen.
- It also contains new heavier elements.
- A black hole is another allowed central outcome.
Hydrogen and new heavier elements; centre may be a neutron star or black hole.
Look for these in your work
- Include the enriched composition.
- Retain both endpoint alternatives.
A bright distant event is labelled a black hole without any remnant evidence. Evaluate the inference.
Give me a hint
An event’s apparent brightness does not by itself identify its compact aftermath.
Compare my reasoning
- A supernova is an event.
- Its central remnant can have different outcomes.
- Further remnant information is needed.
The brightness alone does not establish a black-hole remnant.
Look for these in your work
- Distinguish event and remnant.
- State the missing evidence.
Common mistakes
- Supernova is an event, not the cloud’s name.
- Neutron star OR black hole gives alternatives.
- Brightness alone cannot identify the remnant.
What can you explain now?
What can remain at the centre after a massive-star supernova?
Compare with the explanation
A neutron star or a black hole
These are alternative compact remnants in the required evolutionary model.
After trying it yourself, choose your next review. This is your self-assessment.
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Make it stick
Separate the explosion, expelled nebula and alternative central remnants.
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.