Monday, 18 June 2018

NGC6567: a planetary in full expansion

Young planetary nebulae are not always easy to find because of their tiny size they usually resemble an ordinary star at low telescope power. Yet, with the aid of a nebula filter - UHC or OIII, which blocks all light frequencies apart from those predominantly radiated by these nebulae - they easily stand out as a bright and somewhat fat star against the dark background. If you then increase magnification to as much as your telescope or sky conditions allow, you'll often be surprised. Due to their high surface brightness they let you use extreme high power and not seldom show some extraordinary detail.

Take this little bugger, for example. NGC6567 lies some 4,000 light-years away from us in the direction of the marvelous Sagittarius Stellar Cloud. It gets lost somewhat in the extremely rich star field of the centre of our galaxy, but with the aforementioned method you'll still be able to find it without too many difficulties. At 507x it becomes obvious that this is a planetary nebula and not a star. What's more, its bright inner ring, an enormous bubble of ionised gas that the dying star's expelled some 4,000 years ago, just leapt out at me. This bright bubble's currently expanding at 13km/s, which is not exceptionally high. Yet without any doubt this nebula will become much more spectacular in the course of the following millennia, when it will expand further.

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