Sh2-311 a treasure trove of a lesser known object

[Marko]

In the process last week of tracking down my last 20 or so objects in the Herschel 400 list II (5 left as of now!) I was very taken with a re-observation of the field all about Sh2-311 which sits on top of the Ngc2467 cluster in Puppis. The main object itself and cluster is quite apparent even unfiltered but with a filter this area becomes both a real treasure of an observation as well as an observing challenge. Viewed in my 18" f/3.7 dob with the NPB filter mostly at 216x I discoverd more and more of this varied area the longer I looked. In some ways the main section caused me to think of this as 'the Pup's Eagle' with dimmer wings from the outline of the SW section drawn in MegaStar. This object is on Steve's list from DeepMap as well but my earlier observations were 'weak' and lacked sky conditions so not suitable for the project I was doing.

On this much more careful observation I found the nebulous area to be extending in most directions from the central obvious area just discussed and all together covered close to a degree of sky. We first notice the main cluster with very obvious nebula and next focus on the nice small and round nebulous area of Lbn1066 all about cluster Haffner 19 that is NE of the main cluster. Slipping into deep sky mode I could then go farther on to find assorted huge sections of much fainter nebulous glow attached and going off in most directions from the main cluster specifically off to the NE and off to the SE in a HUGE area that dwarfs the size of the main glow. I'll now keep this on my 'favorites list' to be revisited. I left off the details of my observation as it is not written up from tape yet. I am certain several of you have enjoyed this in the past and may want to discuss this treasure trove of an observation.

[reiner]

Hi Mark,

Great that you are bringing up this object. This is one of my favorites in the Sharpless Catalog and it is one of those real hidden treasures.

My observation from my Sharpless Observing Guide:
22" f/4.5
Already visible w/o filter. OIII> UHC. Central part around star, slightly offset to S. Further parts separated and extending to N and NE. Another extremely large part to E, forming an approximately 30' long crescent open toward NE.

In particular this large area in the E that you mention, forming a large crescent, is just fascinating. It is almost exclusively OIII light coming from it.

There is a good image in OIII by Dean Salman here
http://www.sharplesscatalog.com/sharpless/SH2-311.aspx

edit: Note that the image is rotated with S up

[Marko]

Ahh-Ha! Sue has this covered this object nicely in the March issue of S&T and as such we can say this object is 'officially' a 'Deep-Sky Wonder'. Thanks Sue. A very interesting area to be sure.