Multiple choice general knowledge science & technology The first planet detected outside the solar system was orbiting what star? 51 Pegasi Supernova 1987A Jupiter Gliese 581 Reveal answer Fill a bubble to check yourself A Correct answer Explanation 51 Pegasi b was discovered in 1995 by Mayor and Queloz, the first exoplanet found orbiting a main-sequence star. Supernova 1987A is a stellar explosion, Jupiter is within our solar system, and Gliese 581's planets were discovered later.