SC: astronomers working at telescopes

[herogmat]

Sentence 1:
An international team of astronomers working at telescopes in the Canary Islands and Spain has detected at least 18 huge gas spheres estimated to have 5 to 15 times the mass of Jupiter, the solar system’s largest planet.

Sentence 2 :
An international team of astronomers, working at telescopes in the Canary Islands and Spain ,has detected at least 18 huge gas spheres estimated to have 5 to 15 times the mass of Jupiter, the solar system’s largest planet.

Is there any difference in the meaning of the sentences ?

[sanyalpritish]

I dnt see any new appos., in the 2nd questions, in the 2nd question there are commas, wats ur question

[RonPurewal]

Sentence 1:
An international team of astronomers working at telescopes in the Canary Islands and Spain has detected at least 18 huge gas spheres estimated to have 5 to 15 times the mass of Jupiter, the solar system’s largest planet.

Sentence 2 :
An international team of astronomers, working at telescopes in the Canary Islands and Spain ,has detected at least 18 huge gas spheres estimated to have 5 to 15 times the mass of Jupiter, the solar system’s largest planet.

Is there any difference in the meaning of the sentences ?

there's a rhetorical difference, although certainly way too small of a difference to be relevant to the gmat.

-- THE BELOW EXPLANATION IS WAY, WAY BEYOND THE SCOPE OF THE GMAT --

in (a), "working at telescopes in the X" is an essential modifier. this means that the astronomers are not considered just as astronomers, but rather as "astronomers working at telescopes in the X". in other words, the act of working at telescopes in the X is considered part of the identity of these astronomers; they basically can't leave these telescopes without losing their identity.

in (b), they are just "astronomers", and they happen to be working at telescopes in location X (nonessential modifier --> disposable this time). if they were to get up and move to other telescopes, their identity would not suffer as a result.