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7/27/2012

Campbell's Hydrogen Star










Well, I came across another object that I put on the list for August to observe.  I got it from the Deep Sky Forum and the link for that is down below.  Be careful.  If you like faint fuzzies for large scopes or challenges for intermediate scopes you may get hooked on that forum!  Dark Sky Apparel brings you that site and I honestly do encourage you to check it out.  You may not be able to tell from all my posts, but planetary nebula are by far, my favorite objects to observe.  I've said it before, and I'll probably say that again.  Galaxies are also wonderful, but for me, a planetary nebula reminds me that the fate of our own solar system is finite, there will be an end.  There are all kinds of reasons why I find that both intriguing and interesting but I won't touch on that here.

Anyway, Campbell's Hydrogen Star is a Planetary Nebula in the constellation of Cygnus.  Yet it is a different planetary nebula.  It doesn't respond to the OIII filter but responds best to the Hydrogen Beta Filter (another use besides the Horsehead Nebula for one of these filters (see my post of David Knisely's HB Filter list i.e. the objects listed here that he has come up with):


1. IC 434 (HORSEHEAD NEBULA)
2. NGC 1499 (CALIFORNIA NEBULA, naked eye and RFT)
3. M43 (part of the Great Orion Nebula)
4. IC 5146 (COCOON NEBULA in Cygnus)
5. M20 (TRIFID NEBULA, main section)
6. NGC 2327 (diffuse nebula in Monoceros)
7. IC 405 (the FLAMING STAR NEBULA in Auriga)
8. IC 417 (diffuse Nebula in Auriga)
9. IC 1283 (diffuse Nebula in Sagittarius)
10. IC 1318 GAMMA CYGNI NEBULA (diffuse nebula in Cygnus)
11. IC 2177: (Diffuse Nebula, Monoceros)
12. IC 5076 (diffuse nebula, Cygnus)
13. PK64+5.1 "CAMPBELL'S HYDROGEN STAR" Cygnus (PNG 64.7+5.0)
14. Sh2-157a (small round nebula inside larger Sh2-157, Cassiopeia)
15. Sh2-235 (diffuse nebula in Auriga).
16. Sh2-276 "BARNARD'S LOOP" (diffuse nebula in Orion, naked eye)
17. IC 2162 (diffuse nebula in northern Orion)
18 Sh2-254 (diffuse nebula in northern Orion near IC 2162)
19. Sh2-256-7 (diffuse nebula in northern Orion near IC 2162)
20. vdB93 (Gum-1) (diffuse nebula in Monoceros near IC 2177)
21. Lambda Orionis nebular complex (very large, naked-eye)

Please note that IC 5146 is the Cocoon Nebula also in Cygnus and it does make a difference in viewing that faint target.  Another target in Cygnus that is perhaps well known but often overlooked is Campbell's Hydrogen Star.  Located not far from Alberio this is a planetary nebula with some weird spectrograph and emission lines coming out of it.  In truth it is a Wolf Rayet Star that is a carbon star that is very hot and its outer layer is just been thrown off.  Herschel never saw this objects so its not in his catalog, nor is it included in the NGC catalog by Dryer.  It took American astronomer William Campbell to find it in 1899 using the Lick telescope and to determine that it is an actual planetary nebula, though it is small in size.  From Night Sky Info comes this comment: 5" across, an 8-inch reflector at 200x reveals just a small, 9th-magnitude grayish disk. Larger telescopes equipped with an OIII filter will also show the nebula's 11.3-magnitude central star."  Here is a link to their finderchart.

Coming from the Deep Sky Browsing Forum is  this comment and here is the link to it (warning, if you want faint fuzzies for larger scopes this site can be addictive as some of the best visual observers in the world are on this list and actively posting):



The halo itself can be seen with telescopes from the 12”-14” range. Under good to very good seeing the halo could be resolved as a very small ring with better defined and brighter SE and NW ring parts. Hß filters help to resolve the halo from bright and disturbing CS (10,3mag). UHC and [OIII] doesn’t help.
Also very interesting and exciting is the color of the PN. It is one of the few Deep-Sky-Objects from what we can observe visually its red characteristic. Most people with mid range telescopes reported a red or orange CS. But the color itself is formed from the halo. My own experience with 27” showed a white CS and a red to orange halo/ring. There are other reports and observations which confirm this.


So, as they ask there, I will ask here, what did you see when you looked at it?  I'll let you know in about 2 weeks or so.  Here are my finder charts from Starry Night Pro for the object. Please remember, these are faint objects, the color is worth chasing down I believe and thus why I shared it, but this is not a Messier object.  It is a fun challenge object to go after.  The fun is in finding and in observing and seeing what details you can pull out of it as an observer.  You may have Lockwood or Zambuto or top notch optics, but the mirror is only as good as conditions and more importantly, what the observer can discern through their scope and mirror.  I guess in my evolution as an observer, I am learning that it takes an outstanding mirror, an outstanding, experience observer who can handle faint objects and see details there, with the right conditions to make for an outstanding evening.  Just my opinion and thus why I share some of the funner objects to take a peek at.  If your interested perhaps in some further reading I recommend this link which is an essay by Stephen Waldee out of the SF Bay Area on his observations of some well known and not so well known PN's.  The one for PK 64+5.1 is about half way down the page.

Here is a link to the Deep Sky Browser page for PK 64+5.1 and you can also print a finder chart from there if you want.


 Here is the view that includes Alberio, 9Cygni.




Below is the view from 9Cygni.




Last is the view as you approach Campbell's Hydrogen Star.