# 5th Grade Science : Differing Brightnesses of Stars

## Example Questions

### Example Question #1 : Differing Brightnesses Of Stars

Mrs. Johnson's class is investigating the brightness of stars. Mrs. Johnson sets up the investigation, and the students begin working. The first two student volunteers held identical flashlights at an equal distance from the whiteboard. The class decides after noting the lights on the board look the same that when two stars are at an equal distance, they have the same actual brightness. For the second part of the investigation, two student volunteers held the identical flashlights at two different distances. Students observed than the flashlight that is closer to the whiteboard appears to be brighter than the flashlight that is further away from the whiteboard. Their observations are recorded in the data table below.

What inference can the students draw from this demonstration?

The further a star is to Earth, the brighter it will appear.

There is no inference that students can draw from this demonstration.

The closer a star is to Earth, the dimmer it will appear.

The closer a star is to Earth, the brighter it will appear.

The closer a star is to Earth, the brighter it will appear.

Explanation:

The flashlights in this demonstration are placeholders for stars. There is no way that a class can investigate a real star close up, so an alternative light source must be used. The Victoria Department of Education and Training gives some background information on stars (or a flashlight in this case), "There are more stars in the sky than anyone can easily count, but they are not scattered evenly, and they are not all the same in brightness or color." The closer a source of light is to our line of vision, the larger it will appear and the brighter. The flashlight that is only 2 feet from the board will appear brighter and more massive than the flashlight held at 4 feet.

### Example Question #2 : Argue And Support That Brightness In Stars Is Due To Distance

Four students are making claims about stars and their apparent brightness.

• Ursula: "The star that appears brightest to us is the Sun because it is the largest in the galaxy."
• Gretel: "The Sun appears to be the brightest star because it is the closest to Earth."
• Hansel: "The Sun is the brightest star when looking from Earth because it is the hottest."
• Phoebe: "I have seen brighter stars than the Sun; it isn't that great."

Their teacher shares the following information from NASA, "Of course, the star that appears the brightest to all of us on Earth is the Sun. Although it is a rather typical star, not all that different from many of the ones you see at night, we live so close to it that it outshines everything else. Even the next closest star is more than a quarter of a million times farther from Earth, so it is not surprising that the light from the Sun overwhelms that from other stars."

Which student's argument is supported by the teacher's research?

Phoebe

Ursula

Hansel

Gretel

Gretel

Explanation:

Gretel's claim is supported by the research from NASA that her teacher presented. The Sun appears to be the brightest star because it is closest to Earth. It does not appear brightest because its the hottest, largest, or the brightest in the galaxy. "We live so close to it that it outshines everything else." This is the reason the Sun looks so bright.

### Example Question #1 : Argue And Support That Brightness In Stars Is Due To Distance

NASA gives background information on the brightness of stars, "To find out the true brightness of a star; scientists need to know how far it is. Although there are some very clever ways of gauging the distances to stars, they generally work well only for stars that are in the Sun's neighborhood of the Milky Way galaxy. The more distant stars are just so fantastically far from us that measuring their distances accurately is too difficult. Making it still harder to know how bright a star is, there is a kind of patchy fog between the stars - space is not truly empty. Although it is not the same as the fog on Earth, gas and dust in space can dim the light of stars. Without a good way to know how much of this interstellar fog is blocking the light, there is no reliable way to discover the true brightness of a star."

Which piece of text evidence supports the claim that it is possible to measure the actual brightness of stars?

"To find out the true brightness of a star; scientists need to know how far it is."

"The more distant stars are just so fantastically far from us that measuring their distances accurately is too difficult."

None of the answer choices are correct

"Without a good way to know how much of this interstellar fog is blocking the light, there is no reliable way to discover the true brightness of a star."

None of the answer choices are correct

Explanation:

There is no piece of text evidence that supporters the claim that it is possible to measure the actual brightness of stars. There are two lines from NASA that dispute the claim, "To find out the true brightness of a star; scientists need to know how far it is. Without a good way to know how much of this interstellar fog is blocking the light, there is no reliable way to discover the true brightness of a star.". This evidence makes it clear that it is not possible to measure the distance or the brightness of a star.

### Example Question #1 : Differing Brightnesses Of Stars

Dot makes a statement to her teacher. "The Sun is the brightest star in the galaxy and no other star can compare." She provides this evidence from NASA to support her argument, "Although we don't know which star truly is the brightest, we know some are remarkably bright. You can see one of them any clear night this summer. Deneb is northeastern of the three stars that form a large and easily seen grouping called the Summer Triangle. While Deneb shines the brightest in the constellation Cygnus, 17 other stars glow brighter in our night skies. But Deneb is much farther from Earth than most of the other stars you see, and this giant is around 100,000 times brighter than the Sun. If Deneb were the same distance from Earth as Vega, another star in the Summer Triangle, not only would it outshine all the stars and planets visible at night, but it would even be bright enough to see in the daytime!"

Dot's argument and evidence are in sync.

False

True

False

Explanation:

Dot's argument is in complete contradiction with the evidence she provided! The statement from NASA says that there is a star 100,000 times brighter than the Sun, and if it were closer, it would be bright enough to see in the daytime. This is the opposite of her claim and argument. The Sun appears brightest because it is closest to us and is the only star in our Solar System, but there are other stars in the galaxy that are much brighter.

### Example Question #5 : Argue And Support That Brightness In Stars Is Due To Distance

"To find out the true brightness of a star, scientists need to know how far it is. Although there are some very clever ways of gauging the distances to stars, they generally work well only for stars that are in the Sun's neighborhood of the Milky Way galaxy. The more distant stars are just so fantastically far from us that measuring their distances accurately is too difficult. Making it still harder to know how bright a star is, there is a kind of patchy fog between the stars - space is not truly empty. Although it is not the same as the fog on Earth, gas and dust in space can dim the light of stars. Without a good way to know how much of this interstellar fog is blocking the light, there is no reliable way to discover the true brightness of a star." - NASA

Which piece of evidence from NASA's passage describes a complication with measuring a star's actual brightness?

"Without a good way to know how much of this interstellar fog is blocking the light, there is no reliable way to discover the true brightness of a star."

"The more distant stars are just so fantastically far from us that measuring their distances accurately is too difficult."

"Although there are some very clever ways of gauging the distances to stars, they generally work well only for stars that are in the Sun's neighborhood of the Milky Way galaxy."

"To find out the true brightness of a star, scientists need to know how far it is."

"Without a good way to know how much of this interstellar fog is blocking the light, there is no reliable way to discover the true brightness of a star."

Explanation:

NASA's passage explains that space dust is a complication with measuring a star's actual brightness. Stars are extremely far from Earth, and the interference of space dust can cause scientists to be unable to measure the distance accurately. The dust is much like a fog is on Earth adn clouds the view.

### Example Question #6 : Argue And Support That Brightness In Stars Is Due To Distance

Besides the Sun, all other stars appear to be pin-pricks of light. Why do the other stars appear so small?

The other stars are not as large as the Sun.

The other stars are not as close as the Sun.

The other stars are not as hot as the Sun.

The other stars are not the same color as the Sun.

The other stars are not as close as the Sun.

Explanation:

NASA provides some background on the Sun compared to other stars, "Of course, the star that appears the brightest to all of us on Earth is the Sun. Although it is a rather typical star, not all that different from many of the ones you see at night, we live so close to it that it outshines everything else. Even the next closest star is more than a quarter of a million times farther from Earth, so it is not surprising that the light from the Sun overwhelms that from other stars." Due to the Earth's close (in relative terms) proximity to the Sun, it appears brightest to use because it is closer than all other stars in the galaxy.

### Example Question #1 : Argue And Support That Brightness In Stars Is Due To Distance

Which statement about the Sun is correct?

The Sun is the farthest star to Earth.

The Sun has the same surface temperature as Neptune.

The Sun is the closest star to Earth.

The Sun is made of rocks, ice, and minerals.

The Sun is the closest star to Earth.

Explanation:

NASA provides some background on the Sun compared to other stars, "Of course, the star that appears the brightest to all of us on Earth is the Sun. Although it is a rather typical star, not all that different from many of the ones you see at night, we live so close to it that it outshines everything else. Even the next closest star is more than a quarter of a million times farther from Earth, so it is not surprising that the light from the Sun overwhelms that from other stars." Due to the Earth's close (in relative terms) proximity to the Sun, it appears brightest to use because it is closer than all other stars in the galaxy.

### Example Question #8 : Argue And Support That Brightness In Stars Is Due To Distance

True or False: All of the stars we see in the night sky are part of our solar system.

False

True

False

Explanation:

NASA provides some background on the Sun compared to other stars, "Of course, the star that appears the brightest to all of us on Earth is the Sun. Although it is a rather typical star, not all that different from many of the ones you see at night, we live so close to it that it outshines everything else. Even the next closest star is more than a quarter of a million times farther from Earth, so it is not surprising that the light from the Sun overwhelms that from other stars." Due to the Earth's close (in relative terms) proximity to the Sun, it appears brightest to use because it is closer than all other stars in the galaxy.

The stars that we see in the night sky are part of our Milky Way Galaxy, but they are not part of our solar system. Our solar system only has one star, the Sun. Galaxies contain millions to billions of stars, and depending on their proximity to Earth, some appear brighter than others. They are extremely far from us and not a part of our solar system.

### Example Question #9 : Argue And Support That Brightness In Stars Is Due To Distance

True or False: The Sun is the largest, hottest, and brightest star in our solar system.

True

False

True

Explanation:

NASA provides some background on the Sun compared to other stars, "Of course, the star that appears the brightest to all of us on Earth is the Sun. Although it is a rather typical star, not all that different from many of the ones you see at night, we live so close to it that it outshines everything else. Even the next closest star is more than a quarter of a million times farther from Earth, so it is not surprising that the light from the Sun overwhelms that from other stars." Due to the Earth's close (in relative terms) proximity to the Sun, it appears brightest to use because it is closer than all other stars in the galaxy.

The Sun is the only star in our solar system, so that fact makes the statement true. The Sun is the most massive, hottest, and brightest star in our solar system. There are millions if not billions of stars in our galaxy, and the Sun is not the hottest or largest in comparison, but in our solar system, it is!

### Example Question #10 : Argue And Support That Brightness In Stars Is Due To Distance

Why do many students believe that the Sun is the largest or brightest star?

It appears to be the brightest star we see.

They have measured all of the stars and compared the data.

It can be seen with just our eyes, while all other stars need telescopes to be seen.

It is in our solar system; other stars are not.