Messier's Missing Object

I just wanted to share some fascinating images and information which I received too late to include in a video.

The video was this one about Messier 102 on Deep Sky Videos.

Professor Mike Merrifield mentions that M102 was a late inclusion on Charles Messier’s famous list of objects - contributed by his colleague Pierre Méchain.

Its exact co-ordinates on the sky were not included, just a description of where it could be found.

As our video mentions, Messier later mentioned some co-ordinates, but it seems this has only added to the confusion for astronomers and historians.

I read more on the excellent SEDS database (an amazing Messier resource) and learned of Messier hand-wrote co-ordinates in a personal copy of the list.

This “personal copy” was tantalizing, so I contacted the people at SEDS and asked to see it.

Alas I did not receive a response in time - but eventually I did receive a response.

I was kindly supplied with multiple copies of the document in question - and it turns out Messier’s annotation was not very clear.

First here’s a standard photocopy, and I’ve highlighted Messier’s co-ordinates, which are on a facing page from the actual M102 entry.

Second, a deeper scan to show up more detail of the writing.

And finally a copy annotated by Dan Greely (who supplied the copy to SEDS in 1995) and Audouin Dolfuss. It’s fascinating to see these “astro detectives” at work.

My thanks to Hartmut Frommert from SEDS - the SEDS database is a treasure.

See his detailed article on the matter here.