A Planetary Nebula in Vulpecula
|Apparent size:||8.0′ x 5.7′|
|Diameter:||3.2 light years|
|Distance:||1,400 light years|
|Exposure:||51 x 90sec = 76 minutes.|
|Field of View:||38.7 x 25.7 arcmin. Up is 171 degrees E of N.|
One of the nicest looking planetary nebulae, M27 is also known as the Dumbbell Nebula or the Apple Core Nebula. It’s appearance is that of a prolate spheroid, a wonderful sounding term which basically means “shaped like the ball thrown around in sports like rugby or gridiron” – although why those sports refer to their squashed spheroids as a “ball” is a total mystery!
The oblateness is visible as the faint light blue coloured gas which fades away to the right and left of the object in this image.
The nebula is expanding at a rate of 2.3″ per century, so is barely noticable over a human lifetime – despite its expansion velocity of 31 kilometres per second.
The object is estimated to date back 9,800 years, when the gas was ejected from a dying sun-like star, leaving the stellar core remnant (clearly visible at the centre of the nebula) to fade as a white dwarf over trillions of years, until it becomes a black dwarf in the unimaginable far distant future.
|SkyWatcher Esprit 120 mm apochromatic 3-element refractor; 840 mm f/l @ f/7.|
|Field flattener; ZWO Duo-band (H alpha & OIII) filter; 2x Powermate|
|SkyWatcher EQ6-R Pro mount; ZWO ASI120 guide camera.|
|Imaging camera: ZWO ASI 071 MC Pro (CMOS 28.4mm 16 Mpx).|
|Software: EQMOD, Cartes du Ciel, PHD2, SharpCap, Gimp.|
|Cosmic Focus Observatory location: 34° South.|
See annotated image at Astrometry.net