Longmore 16

[Raul Leon]

Hi everyone,
This past weekend I ran upon Longmore 16 , planetary nebula in Scorpius. I was surprised at how easy it was in my 15 in Dob, with an OIII filter. I made a sketch, but couldn't find any information only, the basics. Does this planetary nebula have other monikers or catalogue numbers beside the PK and PN catalogue? I only have seen one photo., a crappy DSS photo which you can barely detect it at all. Any observation notes, photos or sketches are appreciated. Thank you, Here is my sketch.longmore 16.jpg I used an 8mm Ethos 198x magnification

[Mark SW]

NAME PK PN G RA DEC SIZE MAG Con

Lo 16 349-04.1 349.3-04.2 17,35.7 -40,12 83 13.4 Sco
https://web.archive.org/web/20130817...s/secgpnv7.xls
Hope this helps a little

[Steve Gottlieb]

This is a good one! I observed Lo 16 back in July 2002 with an 18-inch. Unfortunately it's pretty far south for U.S. observers north of +35° latitude. My observation was from rural Australia with the planetary nearly overhead.

Immediately picked up at 171x using an UHC filter. I was pleasantly surprised to find a relatively prominent non-NGC/IC planetary. It appeared as a fairly faint, well-defined disc, ~80" diameter. A mag 12 star is just off the north edge.


Here are descriptions by a few other observers. The last one is also from Australia.

Kent Wallace (20"): at 79x, a large diffuse, round, relatively bright disc. Could see with averted vision alone, but the OIII filter was used to find the PN. The image is better at 134x. Good response to OIII filter, fair response to UHC, no response to H-B. At 254x, no central star was visible.

Kent Wallace (8"): On 8/9/96 I was able to see Lo 16 in Larry's C-8 at Mt Emigdio. This brings my total sightings with a 8" to 306.

Eric Honeycutt (22"): 74x/118x/216x and O-III: A dim to obvious PNe that is highly elongated. An interesting granular texture is evident over the entire surface of the object. This is a direct vision object. Averted vision and 216x reveals internal mottling. 118x shows less details but it is more noticeable. A nice surprise.

Les Dalrymple (12"): Obvious. Brightens somewhat with the UHC, found on the S side of an isosceles triangle of mags 10 + 11 *s. Profusely littered field. Diffuse edged, sizable, just over 1' dia rising in brightness slightly to centre without zones. No nucleus. No central *. No colour.

[Raul Leon]

Thanks Mark and Steve

[oliva]

Hi Raúl,

I observed Longmore 16 from Namibia in 2018:”This planetary nebula is easy to spot at 100x. However, a diffuse spindle is initially visible, which lies in the middle of a star field. With Increasing brightness towards the center and with a diffuse center itself. When patiently observed, a slightly oval, almost round, diffuse fog finally appears, which has the described bar in the middle. Bar is almost N-S oriented. Responds to OIII so that you can exclude a galaxy. Still better without a filter. 454x magnification. Seeing 3-4.”

Telescope was a 25” Obsession Dobson and magnification was 454x. No filter was used. Below my sketch.

DE275E05-C537-4781-B479-E38D087D7A3F.jpeg

Rarely observed object.

Oliver

[Raul Leon]

Thanks Oliver, excellent sketch and narrative!

[Bill Weir]

Possibly a bit too low to the horizon from my location of 48°28’N, and especially this year since that area of Scorpius dipping lower as the days go by. I certainly will try to remember it next year as I do my annual observation of NGC 6302. It will be a good challenge and all depends on clarity of the sky looking over the ocean towards Washington State. If I can see the peaks of the Olympic Mountains I’m good to go.

Bill