GMAT Sentence Correction (SC) | Re: Although the first pulsar, or rapidly spinning collapsed

They can't be redundant. The sentence focuses on the time of the observation of the first special star that was sighted. "To be sighted" means the first one was sighted from the Earth. "was observed" is simply the main verb in that sentence.

Also, if you combine them: "The first pulsar was observed in the summer of 1967",
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