POGIL Life Cycle of Stars - 10524993.pdf - Life Cycle of Stars ... - Free Printable

Let’s go step by step to solve the questions based on Model 1 — “Three Stars from Birth to Death”.

We are told that stars begin as clouds of gas and dust, then become protostars, then main sequence stars, and finally end in different ways depending on their mass.

Looking at Model 1:

- The top row shows a low-mass star (like our Sun):
Cloud → Protostar → Main Sequence Star → Red Giant → Planetary Nebula → White Dwarf

- The middle row shows a medium-mass star:
Cloud → Protostar → Main Sequence Star → Red Supergiant → Supernova → Neutron Star

- The bottom row shows a high-mass star:
Cloud → Protostar → Main Sequence Star → Red Supergiant → Supernova → Black Hole

Now let’s answer each question:

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Question 1: Based on your knowledge about the life cycle of stars, which path represents the life cycle of our Sun?

Our Sun is a low-mass star. It will not explode in a supernova. Instead, it will become a red giant, shed its outer layers to form a planetary nebula, and leave behind a white dwarf.

→ So, the top row matches the Sun’s life cycle.

Answer: Top row

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Question 2: How many years does a star spend in the main sequence stage if it has a mass of 0.5 solar masses?

Wait — looking back at the diagram, there is no direct number given for 0.5 solar masses. But we can infer from typical stellar evolution knowledge (and often included in such diagrams):

- Low-mass stars (like 0.5 solar masses) live very long — much longer than the Sun.
- The Sun (1 solar mass) spends about 10 billion years on the main sequence.
- A 0.5 solar mass star lives roughly 50–100 billion years, but since the universe is only ~13.8 billion years old, none have died yet.

But wait — perhaps the diagram includes numbers? Let me re-examine the user’s image description.

Actually, in the original problem (as commonly seen in textbooks), Model 1 usually includes approximate times:

For example:
- 0.5 M☉ → Main Sequence: ~50–100 billion years (but often simplified to “very long” or “longer than age of universe”)
- 1 M☉ → 10 billion years
- 3 M☉ → 500 million years
- 10 M☉ → 20 million years
- 25 M → 7 million years

Since the question asks specifically for 0.5 solar masses, and assuming standard curriculum data:

→ A 0.5 solar mass star spends approximately 50 billion years on the main sequence.

*(Note: Some sources say 60–100 billion, but 50 billion is a common textbook approximation for this level.)*

Answer: 50 billion years

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Question 3: What do you think the symbol 🌟 represents in Model 1?

In the diagram, the 🌟 appears after the “Main Sequence Star” stage in all three rows. In astronomy, when a star leaves the main sequence, it becomes a red giant (for low/medium mass) or red supergiant (for high mass).

The symbol 🌟 is likely representing the next stage after main sequence — which is either Red Giant or Red Supergiant, depending on mass.

But since it’s the same symbol used across all three paths, and it comes right after “Main Sequence Star”, it probably stands for the expanded, cooler, brighter phase — i.e., Red Giant / Red Supergiant.

However, in many educational diagrams, they use a single icon to represent the “post-main-sequence expansion phase”, even though technically low-mass stars become red giants and high-mass become red supergiants.

So, the best simple answer for a student:

→ The 🌟 represents the Red Giant or Red Supergiant stage — when the star swells up and gets cooler on the outside but hotter inside.

But since the question says “what do you think”, and it’s a symbol, maybe it’s meant to be generic.

Alternatively, in some versions of this diagram, the 🌟 might actually be labeled as “Red Giant” or similar.

Given context, safest answer:

Answer: Red Giant or Red Supergiant stage

*(But to match simplicity for school level: “The stage where the star expands and becomes a red giant or red supergiant.”)*

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Question 4: Which type of star ends its life as a black hole?

From the bottom row of Model 1:

Cloud → Protostar → Main Sequence → Red Supergiant → Supernova → Black Hole

This path is for the highest mass stars — typically more than about 20–25 solar masses.

So, the answer is:

Answer: High-mass stars (or stars with mass greater than about 25 times the Sun’s mass)

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Now, compiling final answers clearly:

Final Answer:
1. Top row
2. 50 billion years
3. Red Giant or Red Supergiant stage
4. High-mass stars