LSAT Explanation PT 32, S1, Q24: Science journalist: Brown dwarfs are celestial

LSAT Question Stem

Which one of the following is most strongly supported by the science journalist's statements? 

Logical Reasoning Question Type

This is a Most Strongly supported question. 

Correct Answer

The correct answer to this question is C. 

LSAT Question Complete Explanation

Let's first analyze the passage and break down the information given. The passage is discussing brown dwarfs, which are celestial objects with more mass than planets but less mass than stars. They are identified by their mass and whether or not lithium is present in their atmospheres. The passage then explains that stars at least as massive as the Sun have lithium remaining in their atmospheres, while stars with less mass than the Sun have no lithium because it has been consumed in their nuclear furnaces. Finally, the passage states that a brown dwarf does not have a fully functional nuclear furnace, so its lithium cannot be consumed.

The question type is a Must Be True (MSS) question, which means we need to find the answer choice most strongly supported by the information provided in the passage.

Now, let's go through each answer choice:

a) Any celestial object without lithium in its atmosphere is a star with less mass than the Sun.

While it is true that stars with less mass than the Sun have no lithium, this answer choice is too broad by saying "any celestial object." The passage only provides information about stars and brown dwarfs, so we cannot assume this statement is true for all celestial objects.

b) Any celestial object with lithium in its atmosphere has a nuclear furnace that has incompletely mixed the object's elements.

This answer choice is incorrect because it assumes that all celestial objects with lithium in their atmospheres have nuclear furnaces. The passage only discusses stars and brown dwarfs, so we cannot make this assumption for all celestial objects.

c) No celestial object that has no lithium in its atmosphere is a brown dwarf.

This answer choice is correct because the passage states that a brown dwarf does not have a fully functional nuclear furnace, so its lithium cannot be consumed. This means that brown dwarfs must have lithium in their atmospheres. Therefore, if a celestial object has no lithium in its atmosphere, it cannot be a brown dwarf.

d) No celestial object with lithium in its atmosphere has less mass than the Sun.

This answer choice is incorrect because it is too broad. The passage only provides information about stars and brown dwarfs, but this statement refers to all celestial objects. We cannot make this assumption based on the information provided.

e) No celestial object less massive than a brown dwarf has lithium in its atmosphere.

This answer choice is incorrect because the passage does not provide information about celestial objects less massive than brown dwarfs. We cannot make this assumption based on the information given.

In conclusion, the correct answer is choice (c), as it is most strongly supported by the information provided in the passage.