haʊˈɛvɚ, ɪf sˌʌm ɹˈeɪdɪəl vəlˈɑːsᵻɾi ɪz ˌɪntɹədˈuːst, ðiːz ˈɔːɹbɪts nˈiːd nˌɑːt biː stˈeɪbəl ˈaɪ.ˈiː., ɹᵻmˈeɪn ɪn ˈɔːɹbɪt ɪndˈɛfɪnətli nˈɔːɹ klˈoʊzd ɹᵻpˈiːɾᵻdli ɹᵻtˈɜːnɪŋ tʊ ɛɡzˈæktli ðə sˈeɪm pˈæθ.
However, if some radial velocity is introduced, these orbits need not be stable (i.e., remain in orbit indefinitely) nor closed (repeatedly returning to exactly the same path).