Campbell's Hydrogen Star

[nytecam]

Campbell's Star is a brightish mag 9.6 near stellar PN in Cygnus immediately north of Albireo. Sometimes described as a proto-planetary nebula and variously named HE2-438, PK64+5.1 and PNG 64.7+5.0. The PN is in a crowded Milky Way starfield but if a static scope is centred on globular M56 to the west, Campbell's Star will transit the field 18 minutes later ~20' [2/3 moon diam] to the north of centre. A high magnification needed to see it's nonstellar.

When imaged a long focal length needed [i used my Meade 3000mm f/10 SCT+SX Lodestar-C OSC cam] as the PN disk is only 7.5"arc diam eg twice the diam of planet Uranus! It records, as its name implies, as bright red or pink - a feature shared in my pics of PNe "Bowtie" NGC 40 in Cepheus and IC418 in Lepus as posted on YouTube and via my link below.

Well worth a look as perfectly placed after dusk currently and throughout the autumn. As cloud intervened last night I was going to dump my sole 10s test exposure [below] but glad I didn't! Field stars to mag 13 are recorded and the PN is clearly non-stellar and very pink! I need to return for more

[Nightfly]

This is a real challenge to image. Nice job!

I love the color of this object. I've added it to my list of object to check out next time out. That is if the weather ever clears.

Thanks for reminding us of its existence!

[DirkSteele]

I second that. Great colour in that object.

[todd8137]

Great color

Pat

[Gina]

Interesting

[AlexxxAA]

Great work on this. Great zoom as well. Not anyone dedicates time to these obscure objects.

[nytecam]

Thanks everyone for your interest Dug out an old pic showing why C* is pink via a simple spectrum taken with my homemade spectroscope [barlow+DV-prism+afocal cam] eg the very strong hydrogen-alpha emission @ 656nm in red - the other emission lines are very weak by comparison.

For direct comparison [lower right] is a shot of M57 through the Rainbow Optics grating - clearly the green-blue merge of OIII+H-beta dominate with H-alpha weak. More PN spectra @ http://home.freeuk.c...vin/pnspect.htm Hope post is of interest

[NickK]

Love the whole image spectrogram - was that just from the rainbow gratings?

[nytecam]

Love the whole image spectrogram - was that just from the rainbow gratings?

No Nick - it's from my homemade spectroscope as in pic - unfortunately a prism spectrum has no reference point like the Rainbow Optics grating so difficult to identify the emission lines beyond strong H-alpha line. Will pop the Rainbow grating on the scope soon for a new spectrum of Campbell's Star and compare with Vega spectrum with known absorption [dark] lines

Here's my better field pic from Wednesday night under clear skies - measuring the PN disk = ~8.2"-arc eg close to 7.5" published

[Ransu]

Very intresting target thank's for letting us know, your post made me try this with C14 and ATIK16HR, this is my second colour image i have ever took with b&w astrocamera.

I think i have to try this target again with modded 1000D and h-alfa filter.

Your spectroscopy pages are also very intresting, i think i have to start read more about spectroscopy.

Here is image of same target

[squeaky]

No Nick - it's from my homemade spectroscope as in pic - unfortunately a prism spectrum has no reference point like the Rainbow Optics grating so difficult to identify the emission lines beyond strong H-alpha line. Will pop the Rainbow grating on the scope soon for a new spectrum of Campbell's Star and compare with Vega spectrum with known absorption [dark] lines

Here's my better field pic from Wednesday night under clear skies - measuring the PN disk = ~8.2"-arc eg close to 7.5" published

That's because your collimation, focus and tracking are rubbish. Fancy being a whole 0.7 arc seconds out!

Kidding aside - that's a great shot of a tough target.

[Shibby]

Fascinating planetary and a cracking second image of it!

[squeaky]

I looked it up in Stellarium and it took me a little while to be fairly confident that I have the scale right. There's a difference in the detail - some because Stellarium isn't a hundred percent accurate (I read somewhere) and some because there will be a certain amount of proper motion evident since these are a few years apart...

[nytecam]

Very intresting target thank's for letting us know, your post made me try this with C14 and ATIK16HR, this is my second colour image i have ever took with b&w astrocamera. I think i have to try this target again with modded 1000D and h-alfa filter. Your spectroscopy pages are also very intresting, i think i have to start read more about spectroscopy. Here is image of same target

Great image Ransu and nice to see you know where north is - a rarity on astro fora

[nytecam]

What a buzz Last night slapped Rainbow Optics grating before Lodestar-C OSC for my first field spectrum of this star for awhile but this time in spectacular colour below - data on image Included is spectrum taken during session of M57 for comparison - note red image at 656nm and cyan OIII+H-beta blend ~500nm - these corrolate with Campbell's Star spectrum above which, due to tiny PN's size, are sharper and better resolved in OIII and H-beta lines in green/blue boundary just evident.

The yellow line is probably helium. The faint emission lines [brighter blobs] extend to the extreme blue to right fading ~400nm are probably part of the hydrogen [balmer] series. As the camera is unfiltered [apart from Rainbow grating!] the spectrum extends into the infra-red region eg the colourless part of spectrum to extreme left to ~ 800nm ! More work to extract and 2D profile showing line intensity - good fun