M102 – the mysterious Messier object

About the Object

M102, also sometimes referred to as the spindle galaxy,  is one of the less frequently imaged Messier objects. Astrobin list some 300 images at the time of this writing - compare this to 1000 for M109, 4500 for M106 or 9000 for M101. For a Messier galaxy, M102  is also comparably small in size. Also the history of M102 and its common association with NGC5866 is somewhat convoluted - it is unclear whether Messier (or better Pierre Méchain) actually meant this object or whether it was a double identification of M101. Others argue that whatever they observed was rather NGC5879 or NGC5928.

But M102 is an interesting object on its own right. It could be seen as the poster child of a S0 galaxy. It has a nice dust band at its center with some interesting faint substructures, while the box-shaped outskirts is highly indicative of a more active, accretion dominated formation history with stars being on box-like orbits.

Observation Notes

Taking and processing the image took some efforts. The nights are very short at 52N (actually we don't reach astronomical darkness), whether conditions were quite unstable and fluctuating (had to rescue my scope a couple of times from incoming rain showers) in  the past couple of weeks and the high latitude also meant lots of satellite trails to be cleaned (thank you, Elon). But at the end, a IMO pretty pleasing image emerged, also thanks to other objects in the apparent neighborhood such as NGC 5862 and NGC 5870.

Revision A is the full field taken, revision B is a zoom onto M102

Data were taken on 2024 May 28 and June 7, 8, 9, and 11.

Technical Details

View the full-resolution image together with complete acquisition and processing details on AstroBin.