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IGCSE · Cambridge (CIE) · 0973

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 P6.2.2 · Stars

Stars · Cambridge IGCSE 0973 · P6.2.2
Exam scope and assessment notes

Mapped to the named 0973 section using teaching from the corresponding single-science course. A 0973-specific review of every Core and Supplement objective is still in progress. Written practice is self-checked; it does not demonstrate supervised laboratory competence or award an official Cambridge grade. This qualification reports two grades on the 9–1 scale; confirm the entry route for your zone and exam series.

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.
The two products are an expelled nebula and an alternative compact remnant, not an obligatory chain through both remnants.Massive-star supernova productsMore-massive branchSupernova eventNebulaHydrogen andnew heavierelementsCentralremnantNeutron starOR black holeCloud and remnant are separateSchematic · no time or mass scale
The two products are an expelled nebula and an alternative compact remnant, not an obligatory chain through both 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.

Sources for this lesson

Pause and explain

What can remain at the centre after a massive-star supernova?

Put the idea to work

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
  1. Name the event as supernova.
  2. Identify a nebula containing hydrogen and heavier elements.
  3. 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.

1 · Guided

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
  1. Stable star expands to a red supergiant.
  2. A supernova expels an enriched nebula.
  3. 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.
2 · Independent

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
  1. The nebula includes hydrogen.
  2. It also contains new heavier elements.
  3. 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.
3 · Transfer

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
  1. A supernova is an event.
  2. Its central remnant can have different outcomes.
  3. 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.
Recall without your notes

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.

Your review choice appears on Today. Sign in to sync it across devices.

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.

Keep learning Sciences — Co-ordinated (9-1)

Course scope and assessment

This 9–1 pathway maps all 152 detailed subject-content sections in the published 0973 syllabus for exams in 2028 and 2029. The course map follows the same 2028–2029 section codes as Cambridge's A*–G 0654 syllabus, while keeping 0973's grading and entry rules separate. It adapts lessons from the related single-science courses and excludes clear single-science-only topics. A 0973-specific objective-by-objective review, Core/Supplement audit, human subject-teacher review, supervised laboratory experience and cumulative assessment remain in progress. Written practice is self-checked and does not predict an official grade. The separate 2025–2027 syllabus has not been reconciled here. Cambridge lists 0973 only in a limited number of administrative zones: June in zone 3 and centres in Oman and the UAE; November in zone 3 only. Confirm entry with your centre.

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