Two orbit models for the Gliese 581 system are being considered currently. An orbit model is a scientific model that astronomers create as a hypothesis of how a star's planets go through their orbits. One has four planets with eccentric orbits, and the other has six planets with circular orbits.
t uː WORD_BOUNDARY ɔ ɹ b ɪ t WORD_BOUNDARY m ɑ d ə l z WORD_BOUNDARY f ə ɹ ð ə WORD_BOUNDARY ɡ l iː z ə WORD_BOUNDARY f aɪ v h ʌ n d ɹ ɪ d WORD_BOUNDARY eɪ t i WORD_BOUNDARY w ʌ n WORD_BOUNDARY s ɪ s t ə m WORD_BOUNDARY ɑ ɹ WORD_BOUNDARY b iː ɪ ŋ WORD_BOUNDARY k ə n s ɪ d ə ɹ d WORD_BOUNDARY k ɜː ɹ ə n t l i WORD_BOUNDARY ʌ n WORD_BOUNDARY ɔ ɹ b ɪ t WORD_BOUNDARY m ɑ d ə l WORD_BOUNDARY ɪ z WORD_BOUNDARY ʌ WORD_BOUNDARY s aɪ ə n t ɪ f ɪ k WORD_BOUNDARY m ɑ d ə l WORD_BOUNDARY ð æ t WORD_BOUNDARY ʌ s t ɹ ɑ n ə m ə ɹ z WORD_BOUNDARY k ɹ iː eɪ t WORD_BOUNDARY æ z WORD_BOUNDARY ʌ WORD_BOUNDARY h aɪ p ɑ θ ə s ɪ s WORD_BOUNDARY ʌ v WORD_BOUNDARY h aʊ WORD_BOUNDARY ʌ WORD_BOUNDARY s t ɑ ɹ z WORD_BOUNDARY p l æ n ɪ t s WORD_BOUNDARY ɡ oʊ WORD_BOUNDARY θ ɹ uː WORD_BOUNDARY ð ɛ ɹ WORD_BOUNDARY ɔ ɹ b ɪ t s WORD_BOUNDARY w ʌ n WORD_BOUNDARY h ʌ z WORD_BOUNDARY f ɔ ɹ WORD_BOUNDARY p l æ n ɪ t s WORD_BOUNDARY w ɪ ð WORD_BOUNDARY ɛ k s ɛ n t ɹ ɪ k WORD_BOUNDARY ɔ ɹ b ɪ t s WORD_BOUNDARY æ n d WORD_BOUNDARY ð ɪ WORD_BOUNDARY ʌ ð ə ɹ WORD_BOUNDARY h ʌ z WORD_BOUNDARY s ɪ k s WORD_BOUNDARY p l æ n ɪ t s WORD_BOUNDARY w ɪ ð WORD_BOUNDARY s ɜː k j ʊ l ə ɹ ɹ WORD_BOUNDARY ɔ ɹ b ɪ t s WORD_BOUNDARY