Tenmon misso was not performed for all the unusual astronomical phenomena but only for phenomena which had been divined by tenmon hakase or those who had received the imperial decree constituting the mission as the medium of tenmon misso as an omen of a great calamity -- the phenomena which tenmon hakase and those who had received the imperial decree constituting the mission as the medium of tenmon misso had failed to observe were not reported as tenmon misso either.
なお、全ての異常な天文現象が天文密奏の対象になったわけではなく、天文博士・天文密奏宣旨授与者が占った結果、重大な変事の前兆と判断された出来事に限定され、天文博士・天文密奏宣旨授与者が異常の発生に気付かなかった場合も密奏は行われなかった。