Observing the Stars

Using a telescope allows us to see stars and objects in the sky that are very far away. Some objects appear larger or brighter than others. In comparison to other stars in the sky, the Sun appears larger and brighter because it is–

• Much larger

• Much closer

• Much brighter

• Much smaller

Based on the information provided, which of the stars will appear the brightest to observers on Earth?

• Star A

• Star B

• Star C

• Star D

One of the closest stars to Earth is Alpha Centauri A. It is larger than the Sun, yet it appears much less bright. Which of the following is the best explanation for why Alpha Centauri A appears less bright than the Sun?

• The smaller a star is, the more concentrated its energy is, so it appears brighter.

• The difference in brightness is due to the difference in relative distance.

• Dust in Earth's atmosphere absorbs the light of all the stars we see.

• As stars get older, the amount of light they give off decreases.

Harper’s class was studying stars in science and was making comparisons between stars in the sky and the world around them. For Harper’s project, which of the following observations would provide evidence to support the explanation for why some stars that are larger than the Sun appear to be less bright? Select two correct answers.

• A) A large campfire seen at a distance of 1 mile is not as bright as a candle that is 50 inches away.

• B) A 100-watt light bulb is more bright than a 25-watt bulb, even if both bulbs are exactly the same size.

• C) A flashlight appears dimmer if it is covered with different-colored lenses that change the color of the light it gives off.

• D) The brightness of a streetlamp is reduced when viewed from a far distance compared to when it is up close.

• E) The light produced by a firefly is brighter when observed from a distance compared to when it is viewed up close.

Tags

NGSS.MS-PS4-1

On a camping trip, John David noticed that as the Sun went down, he began to see more and more stars in the sky the darker the sky got. How many of the stars that John David observed on his camping trip are closer to Earth than the Sun?

• All of them

• None of them

• About half

• Only one

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NGSS.MS-ESS1-3

With the use of the Hubble Space Telescope, scientist recently discovered a giant runaway star.  It is 90 times larger than the sun and is very hot and blue-white in color.  Why does the sun appear to be brighter than this runaway star when viewed from Earth?

• The sun is a different color than the runaway star.
• The sun is older than the runaway star. 
• The sun is closer to Earth than the runaway star. 
• The sun is made of different elements than the runaway star.