M102 To be or not to be...

[Jessun]

I haven't read up an aweful lot on this it must be said, but I gather that M102 doesn't really exist. It may be a duplicate observation, or an observation that got lost and is now in some other catalogue.

So why does the number live on? TheSky puts it on top ov M101. Should it be deleted or is it part of astronomy history?

[rory]

its generally accepted ( i read) that ngc5866 is m102. although some say its a duplicate of 101 as you say.

[Mike73]

Was just reading about the six 'mysterious and missing Messiers'.

M40 and M73 being stars which were mistaken for being faint nebulas but were included in the list anyway.

Then you have M47, M48, M91 and M102 which have all been explained but no one will ever know for sure!

Tut!!! Talk about doing half a job!

[Jessun]

Hmm, there's more! I need to reed up on this, that's clear

[Capricorn]

Lots of arguements about this.

http://messier.seds.org/m/m102d.html

Looks like a reasonable source of information.

In general it is mainly accepted that NGC 5866 is the item, but it is your choice.

Some arguement is about a badly written greek character. Also read somewhere a couple of years back that the idea of it being a duplicate was never put up by Messier but a rival catalogue his that came out of Germany.

SEDS says that there was a deadline of some sort.

Best option is to acept NGC 5866 and go tick it off if you get the chance, then stick an * by the recording.

But the story behind M102 will always cause questions.

[cantab]

What if the reason subsequent astronomers have had trouble locating M102 is that it was actually a comet

[michael.h.f.wilkinson]

I accepted NGC 5866 as M102 when completing my list. Nice side-on galaxy well worth a look-see.

[E621Keith]

After you finished the missing messier list, there is the missing NGC list. I believe they are numbered in the hundreds.

[glowjet]

I have a copy of Roger Sinnotts 1988 re- publication of the NGC 2000.of S.L.E.Dryer`s original catalogue. Just for interest this is what is listed as NGC 5866, Galaxy, RA 15 06.5 Dec +35 46 constellation of Draco, Size 5.2 Mag 10. Description, as originally recorded at the telescope, Very big, considerably large, pretty much extended 146° gradually brighter in the middle. There you have it, but there is no cross reference to M102, in fact there is no NGC No listed for M102 neither M25, M40, and M45.

John.