ɪt wʌz dɪskˈʌvɚd ˌɔn twˈɛnti fˈoːɹ fˈɛbɹuːˌɛɹi nˈaɪntiːnhˈʌndɹɪd θˈɜːɾi ˈeɪt, baɪ fˈɪnɪʃ ɐstɹˈɑːnəmɚɹ ˈɪəjˌɜː vˈɛɪsˌɛlɛ æt tˈɜːkuː əbzˈɜːvətˌoːɹi ɪn saʊθwˈɛst fˈɪnlənd, ænd nˈeɪmd ˈæftɚ dʒˈɜːmən ɐstɹˈɑːnəmɚ fɹˈiːdɹɪtʃ bˈɛsəl.
It was discovered on 24 February 1938, by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland, and named after German astronomer Friedrich Bessel.