All of us know perfectly M 104, the sombrero galaxy.
But I'm not sure everybody knows Abell 70.
The number 70 of the Abell catalogue is a very strange object: the large and faint ring of a planetary nebula AND a little galaxy exactly on line of view of it.
And cherry on the cake (in this case, it's the very right expression), the galaxy is on the top of the ring, slightly leaned on one side, looking as a sombrero on a round head !
If you look at it without filter, the ring is almost rubbed, and if you use an OIII filter the galaxy vanishes.
Here is how I saw it with my 25" dobson: http://www.deepsky-d...l-70/dsdlang/fr
P.S. Oups ! The yellow numbers must be inverted in the first and second view.
Edited by bertandlaville, 19 March 2020 - 03:17 PM.