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Alessandro Ravagnin

Location of Photo:

Rio Hurtado Chile

Date/Time of photo:

10th april 2023


ASA RC1000 f/6.8


During data processing of last ShaRA#4 project, the team noticed the presence of a small object in the periphery of the GUM14/15 complex (main target of the project): this has the typical shape of a planetary nebula, with bright red and green/cyan colors. We immediately searched the "amateur catalogs" for this item but found absolutely nothing. Therefore, we consulted the main astronomical databases, concluding our searches with the SDSS (Sloan Digital Sky Survey) archive. Finally, we had the code name of the object and a page of an old paper catalog describing its main characteristics: He 2-11, planetary nebula with an estimated magnitude of 13.9. Surprisingly, we could not find any amateur narrow-field image of this planetary nebula, and this is the first one! It has been taken with ASA RC1000 from Chilescope service and it is a HOORGB composition. The Spin Nebula, due to its conformation and its origin, is a bipolar planetary nebula about 2,300 light-years away, at the center of which resides an eclipse binary system with a variability of about 3 magnitudes injust over 14 hours. The morphological, photometric, spectroscopic investigations and the mathematical models in the scientific literature delineate a model of He 2-11 as a structure featured by a uniform central core of ionized Oxygen and by two external filamentous protuberances of low-ionized H-alpha. Moreover, these two protuberances intersect perpendicularly two further jets of ionized hydrogen which would confirm the expulsion/exchange of mass and energy typical of a "post common-envelope" central binary system. This very complex term indicates two stars that shared a common shell of plasma for a certain period of their life, continuing to rotate around each other within this shell. About 7000 years ago, this shell was ejected into space generating the He 2-11 nebula, currently expanding at a speed of about 40 km/s.