Sunday, June 25, 2017

NGC5866, Lenticular Galaxy in Draco

Even though there is a set location for M102 in most charts, books and software like Stellarium, there will always be an eternal discussion about where it should have been located. All this story started back in Spring of 1781 when Monsieur Mechain claimed to discover it, share the information with Charles Messier and then 2 years later retracted his discovery (Here is the whole story).

Long story short, later there was theories about it: some of them would say that it was a false-positive, but others that there was a typo in  describing the coordinates. My favorite and the one I found more reasonable is that the typo was writing the Greek letter : Ο (Omicron) instead Θ (Theta). Both stars in Bootes, but they are 35 arc degrees separated from each other. A fundamental error if describing the location with numbers, but a simple trace in the letter that mislead the location.  

Anyways, if the right description is a nebulous object between the stars Theta Bootes (Asellus Primus) and Iota Draconis (Edasich), then I was in the right spot. There is a group of 4 galaxies that would fit in the description, but the brightest is NGC5866 so that is the one I saw and that most material agreed to be M102.

Taking my eyepiece to that spot wasn’t difficult. I started on Edasich and hopped only three arc degrees towards Asellus Primus and then looked around 1 arc degree to the east for the smudge.  At the time of the observation, I only had my 40mm eyepiece so I used it adding a generic 2x barlow and the results were as you can see in the sketch: an obvious scratch of light with a buldge in the middle.

Some time later, in the morning of May 28/2016 I saw it again and this time using my eyepiece Luminos 15mm (100x). I described as a small and fairly bright oval. I guess it isn’t difficult to see under suburban skies so all I have to say is why not to go out and try?

Clear skies,


Edited by: Jennifer Steinberg (editor in chief). 


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