NGC 2976, NGC 2633, M102 Sketch with 21"

[Mathias]

Hello Folks,

here are my sketches from NGC 2976, NGC 2633 an M 102 that i just finished. I observe this galaxies with my 21" Telescope in March 2021, during very good transparency and good seeing on a very dark place in Germany (Schwarzes Moor, Rhön).


Sketch NGC 2976 with 21"



Sketch NGC 2633 with 21"



Sketch M 102 with 21"




Kind Regards
Mathias
https://www.freunde-der-nacht.net/

[Don Pensack]

Has it been settled that M102 is NGC5866 and not a duplicate observation of M101?

[deepskywim]

In Europe, we consider NGC 5866 as M102. I think that in the US, there are only 109 messier objects.

[Don Pensack]

M 102 was discovered by Pierre Méchain on March 27, 1781 and added to his catalog by Charles Messier. Since the deadline for publication in the «Connoissance» was close to 1784, he had no time to verify the observation as usual. Messier attributed. No. 102: «Nebula between the stars ? in the boat and ? of the dragon: it is very faint, next to it is a star of the sixth magnitude.»

However, the position recorded for M 102 does not correspond to any object that Messier or Méchain could have seen. In a letter dated May 6, 1783, Méchain rejected the discovery and assumed it was merely a renewed observation of M 101. For this reason it was generally assumed for more than 200 years that M 101 and M 102 were the same object, namely the galaxy NGC 5457. The stars ? Boötis and ? Draconis mentioned in the description are 42° apart and therefore not suitable for a position determination. If one assumes that ? Boötis was a misprint should actually be called ? Boötis, this is only 11° away from ? Draconis. In between there are a number of galaxies, only NGC 5866 with 9.8 mag is bright enough that it could have been seen with the telescopes of Méchain and Messier. This was suggested by Camille Flammarion in 1917.

Physical Properties
On Simbad, M 102 is assigned to the galaxy NGC 5866, at NED you land at M 101. M 102 is a lenticular galaxy classified as SA0^+ according to de Vaucouleur. We see them directly from the edge on the central dust band. Heliocentric velocities measurements over the past 20 years range from 672 km/s to 728 km/s and distances from 13 Mpc to 15 Mpc (42 to 49 million light years). The diameter is estimated to be about 70'000 light years and the mass to one trillion solar masses.

Whether NGC5866 is a Messier object or not, it is certainly bright enough to be.

[Don Pensack]

One last post from me about NGC5866.
I thought you all might enjoy this spectacular long exposure of the galaxy:
https://www.adamblockphotos.com/ngc-5866.html