HFG 1 (PK 136+05) Observations

[Dragan]

Hey all,

I'm really curious if anyone in the group has ever observed Heckathorn, Fesen and Gull 1 aka HFG1 (PK 136+05) It's a very old, very faint planetary in Cassiopeia discovered in 1982 near the border of Camelopardalis located at 03 03 48.8 +64 53 28. Pictures of it remind me of a Jellyfish or a Horseshoe Crab. I can't imagine it being very bright in an EP though which may be the reason I found only one observation report. That one report being by Reiner here (http://www.reinervogel.net/index_e.html?/LargePN/LargePN_e.html)

Any other reports out there? Sketches?

This is one of those objects I would love to see appear in the eyepiece as it does in pictures! Sadly, I don't think it will! :(

1783

[Steve Gottlieb]

I don't have any eyepiece sketches of HFG 1, but here are 3 observations of this huge, ancient PN. My first couple of observations were back in 1986, 4 years after discovery (http://cdsads.u-strasbg.fr/full/1982A%26A...114..414H).

17.5" (1/16/02): with a 31 Nagler (64x) and OIII filter an extremely faint, huge glow was visible, perhaps 8' in diameter. Generally the hazy region was just an ill-defined "stain" on the sky, but at moments the view sharpened up into a fairly well-defined disc. Several stars are superimposed. Located 7' NE of mag 9.2 HD 18611. This star lies at the NE end of a string of stars heading to the SW and roughly collinear with HFG 1.

17.5" (11/1/86): at 83x and OIII filter appears very large, very diffuse, requires averted vision, at least 7' diameter. Mag 9 SAO 12574 is off the SW side, ~7' from the center of the planetary.

13" (10/10/86): at 62x and OIII filter appears a very faint, extremely large low surface brightness glow requiring averted vision. Can hold steadily at least 80% of time. Several faint stars are superimposed, and a mag 9 star is off the SW edge.

Steve

[Uwe Glahn]

Only one observation? I have five in my logs with four different aperture. All made under very good transparency. Lots of sketches of PNe you can find here (http://www.deepsky-visuell.de/PN.htm). But one after the other:

4", 56x, [OIII], NELM 6m5+
round glow; easy to hold with averted vision

8", 47x, [OIII], NELM 6m5+
faint glow suspected even without filter; with [OIII] faint, but direct vision object; concentrated to its middle; round, diffuse glow

16", 67x-100x, [OIII], NELM 6m5+
direct vision with [OIII], center 2:3 elongated

27", 113x, [OIII], NELM 6m5+
flashy big glow with [OIII]; bright; slightly elongated center; to the NE and SW two separated plobs, NE plob a little brighter but further away; could not see the [OIII] arc in the SE

1784

[Dragan]

Thanks guys!

Uwe, I'm very impressed that you were able to see it in a 4". My preconceived notions were that this would be much more difficult. This is good news.

Now, were either of you guys able to make out any streamers or a tail of any kind?

[akarsh]

Hi all

I've been interested in trying out some of the old and big planetary nebulae for a while now, and this thread reminded me that I really should. I might give HFG 1 a try if the skies and my body co-operate tonight. For others in the forum that might be looking for a reference, here's Reiner's page: http://www.reinervogel.net/index_e.html?/LargePN/LargePN_e.html

Clear skies!

Regards
Akarsh

[akarsh]

Dear All,

Here's from a few hours ago:

31mm Nagler + 18" f/4.5 + OIII:

Estimated diameter of glow ~ 7' 50"
Glow felt round, but lopsided towards the east. (I did not try looking for the "bow shock" like feature in the east). The rim was more prominent in the eastern half.

31mm Nagler + 18" f/4.5 + UHC:

Structure and diameter seems similar to OIII, but the brightness seems even more lop-sided towards the east.

It was not extremely faint, but by no means was it bright either.


Uwe, I am amazed at the amount of detail you pulled out in this object as reflected in your sketch!

Clear skies
Regards
Akarsh