M97 is a planetary nebula in Ursa Major constellation: it is also know as “Owl Nebula”, due to the two black spots on its surface which resemble the head of a owl.
M97 has an apparent extension of 3’ and is one of the largest known planetary nebula, due to its real extension of 3 light years: the central star is a white dwarf with magnitude 14 and surface temperature of 85000 Kelvin. The distance of the nebula is around 2600 light years.
The total mass of the nebula is 0.15 solar masses and its density is extremely low, about a tenth of the average of the other planetaries; this would indicate the high age of the nebula, given that over time it has expanded considerably and its gases have become rarefied. The age would therefore be about 6000 years.
Its particular appearance would instead be due to its toric or toroidal cylinder shape, seen from an oblique perspective.
[text adapted from Wikipedia]
Optic GSO RC12 Truss - Aperture 304mm, focal lenght 2432mm, f/8
Mount 10Micron GM2000 HPSII
Camera ZWO ASI 2600 MM Pro with filter wheel 7 positions
Filters Astrodon Ha 5nm, Astrodon OIII 5nm, Astrodon Gen2 E-Serie Tru-Balance 50mm unmounted RGB
Guiding system ZWO OAG-L with guide camera ASI 174MM
Exposure details Ha 16x900" bin3 -20C + 7x900" bin3 -25C, gain 100
OIII 14x900" bin3 -20C + 10x900" bin3 -25C, gain 100
R 5x300" bin3 -20C, gain 100
G 5x300" bin3 -20C, gain 100
B 5x300" bin3 -20C, gain 100
Total integration 13h
Acquisition Voyager, PHD2
Processing Pixinsight 1.8, Photoshop CS5, StarXTerminator, DxO Photolab 3
Location Promiod (Aosta Valley, Italy), own remote observatory
Date 23/24 January, 23/26 March 2022