Object of the Week July 10th, 2016 - CRL 2688, the Cygnus Egg

Object of the Week - July 10th, 2016, CRL 2688, AFGL 2688, RAFGL 2688, PK 080-6.1, V1610 Cyg, UGC 11668, the Egg Nebula - in CYGNUS

R.A. 21h02m18.6s DEC +36°41'35" (2000)

Size: 1.0' Mag: 13.50

CRL 2688 (the Cygnus Egg) has had a bad case of mis-identification over the years, carrying labels denoting it as a variable star, a galaxy, a planetary nebula, an infrared source, and in Simbad it has about 20 designations! Megastar still calls it a planetary nebula.

Currently CRL 2688 is considered to be a bipolar protoplanetary nebula approximately 3,000 light-years away from Earth. It is basically a Sun-like star that is in the very early stages of becoming a planetary nebula, an expanding cloud of dust and ejected by a dying star that has burned most of its fuel. The Hubble has provided amazing pictures...

http://imgsrc.hubblesite.org/hu/db/i...09-a-print.jpg

http://imgsrc.hubblesite.org/hu/db/i...-web_print.jpg

... and there is a lot of information on the internet explaining just what is happening here. Amazing stuff.

http://hubblesite.org/newscenter/arc...11/background/

http://arxiv.org/pdf/astro-ph/0309677v1.pdf

http://authors.library.caltech.edu/53934/1/36446.pdf

The Egg Nebula is a tiny little fellow and is not much to look at, visually, but learning about its true nature is a fascinating adventure. In my 25" dob it initially looked like an uneven double star of about 8" separation, but boosting the power to 300-500 diameters made each component nebulous, but still with a dark lane between them. The nebulosity around the brighter component (just east of north) smeared outwards along a line connecting the 2 lobes, quickly fading away. There is a smaller and dimmer extension from the dimmer lobe (just west of south). I tried every filter I had (OIII, H-beta, LPR, UHC) but there was no response to any of them. I can only assume that this means that CRL 2688 is mostly a reflection nebula.

Cygnus is well-placed this time of year, so give it a go and let us know!

I believe since it is strongly polarised that it might respond to a polarizing filter, certainly I have seen reports that it does.

Owen

Challenging object Paul.

In the past I tried to catch the conical fans on both sides. I had rare but sure success with the 16"-18" range.
16", 600x, NELM 6m5+
Attachment 2196

With 27" the fans aren't the problem any more when seeing is steady enough. I tried to see the ring-like structures but had no success yet. Did any one catch the rings?

I observed the Egg Nebula last night with my 12" Meade Lightbridge. The seeing was uncommonly good, but there was a lot of haze, so things were dimmer than normal. At 85x (18mm ES82), it was clearly nonstellar, though very small. Tiny, very bright, elongated, a hint of being double. At 170x (9mm ES100) it was clearly double, with a large, elongated blob to the N and a small, fainter, round one to the S. This was also well shown at 324x (4.7mm ES82). The surface brightness is high and it takes magnification well. With averted vision, especially at 170x, the nebula grew towards the N and S, hinting at the fan shaped extensions. The S component grew the most, percentage-wise, more than doubling in length. The N component grew less, but showed hints of the two spikes, at the limit of vision.

I've seen the Egg Nebula in my 63mm Zeiss, so this is definitely an object for telescopes of all sizes.


Clear skies!
Thomas, Denmark