Thanks Paul for flagging this unusual asteroid and the S&T article, which is nicely written.
This object is stable around L4 for a few thousand years at least but looks to be moved around by interactions with Venus. The observational arc is still rather short whilst it is now heading for low solar elongation and has not been observed for over 3 weeks so at almost 22nd magnitude it looks to have moved out of range for a while. Somebody commented on FaceBook about the ‘XL5’ part of its designation – it shows their age or their interest in ‘Fireballs’ !