Blinking Nebula - How do I get a wink?

[Bart]

Hello all,

Could someone tell me the trick to getting the Blinking Planetary Nebula to blink, please. I thought if you stared at it for a while and averted your vision, it would blink. Nothing tonight. Are they fast or slow blinks? What am I looking for? Any help would be appreciated.

Bart

[Stu]

Hi Bart

Sounds like you are along the right lines. I've only seen it on one night's viewing, through my mak, and also a 15" Obsession! I could see it well in both scopes, but obviously better in the 15".

To me, when you used averted vision, you could clearly see a green planetary nebula, then when you look directly at it, the nebula disappears and you just see a star, or maybe it's just it looks stellar. Anyway, switching between averted and direct vision repeatedly gives the blinking effect. It was quite a strong effect for me, and is one of the few objects which shows clear colour to my eyes.

Hope that helps

Stu

[acey]

Don't use a filter, for a start. The blink happens because of the brightness of the central star: when you look straight at the nebula, the star overwhelms the surrounding light and makes the nebula disappear, you only see the star. With averted vision you see the nebulosity. A filter risks killing this effect, because it dims the central star.

You don't need to stare at it, just flick your eye between direct and averted vision and you should see the effect.

If you can't see the nebula without a filter then you need to view it from a darker site. If you still don't see the blink effect then, it may be down to your eyes: we're all different and not everyone will see things the same way.

The object is bright and should be easily seen in a small scope, though a big one will give a more interesting view of the nebulosity.

[Bart]

thanks for the advice, one last question, what mag should I be at?

Barry

[Stu]

Can't remember what we used but as it is a planetary nebula it is quite small so best to use relatively high magnification. Try x100 to x150

Stu

[RikM]

I find the blinking to be more obvious if you get the magnification right. 120x seems to be the best for my 10" scope. If you spend a while looking at the with averted vision so you see the nebula, then look directly at it, it should'blink' off and you are just left with the central star.

[Double Kick Drum]

I couldn't see it blink either (at 80x magnification). Maybe the nebula was still too condensed at that power as I found it quite bright.

[Stu]

Worth persevering with, it's a very noticeable effect when you see it well.

Stu

[Bart]

thanks Gents

[swamp thing]

I tend to ramp up the power when observing small bright targets like this TBH.

I would look at 150-200x mag for this object in my 10"

Regards Steve