In a letter to astronomer Barnaba Oriani of Milan he made his suspicions known in writing: I have announced this star as a comet, but since it is not accompanied by any nebulosity and, further, since its movement is so slow and rather uniform, it has occurred to me several times that it might be something better than a comet.
Kirjas Milano astronoomile Barnaba Orianile rääkis ta oma kahtlustustest järgmiste sõnadega: "Ma teatasin sellest tähest kui komeedist, ent kuna teda ei saada mingi udusus ning pealegi kuna tema liikumine on nii aeglane ja üsna ühtlane, tuli mulle mitu korda pähe, et see võib olla midagi paremat kui komeet.