5 - ESS1.A - Observing the Stars - FINAL (WND 1/10/14)

Module: Observing the Stars

DCI: ESS1.A The Universe and its Stars – The sun is a star that appears larger and brighter than other stars because it is closer. Stars range greatly in their distance from Earth.

PE: 5-ESS1-1 Support an argument that differences in the apparent brightness of the sun compared to other stars is de to their relative distances from Earth.

[Assessment Boundary: Assessment is limited to relative distances, not sizes, of stars. Assessment does not include other factors that affect apparent brightness (such as stellar masses, age, stage).]

The ideas we see in this standard are: 

- the sun is a star

- the sun appears larger and brighter than other stars because it is closer 

- stars range greatly in their distance from Earth 

The basic idea here is that stars which are closer will appear brighter (despite their size or brightness).  

Possible Question Starters:

"In comparison to other stars in the sky, the Sun appears brighter because it is - 

correct answer - closer to the earth 

incorrect answer - a much older star

"Aside from the Sun, the next closest star to the Earth is Proxima Centauri.  Proxima Centauri is many times larger than the Sun, yet it appears dimmer from Earth.  Which of the following is the best explanation for this?" 

Correct answer - stars that are closer to Earth appear brighter than those that are further away

incorrect answer - smaller stars are usually brighter than those that are much larger