[mental4astro (Alexander)]

Thought I'd add one more object to the list as an exercise on using the blinking technique.

I've been raving for some time about M7 being my favourite deep sky object. This colossus of a cluster is at least 1.3 degrees in diameter. At this size, it is no surprise that there lie some other DSOs in the same line of view. M7 boasts no less than three planetary nebulae, three open clusters and one globular cluster within its line of view.

The GC I use as a quick guide to gauge to seeing conditions. It is just visible with an 8" scope from Sydney. The open clusters' stars appear ruby like against the diamonds of M7. The PNs are invisible without the aid of an OIII filter, and blinking is really the only way to spot them from against their background as they are tiny.

The chart below was forwarded to me by the observational guru NGCles. I spotted one of the PNs noted on my very first go at them using the blinking technique from home. Tip: use some decent magnification in order to bring up the size of the disks, otherwise it'll be too difficult. Something in the order of 120X will help. Aperture too helps, but we do what we can with what we've got.

You may also attempt to track down the other PNs noted in the chart too.

M7 is also a fantastic binocular target from a dark site as dark lanes and nebulae run through it. Just beautiful.

Mental.

PS, I'm hoping Suzy will add her challenge to this one. Please do. Mine's a bit light on targets this month.