ASTRO: SH2-80 and newly discovered planetary nebula Li1 part 1

I'll get to the new planetary in a bit first SH2-80.

This is a retake of SH2-80 aka Merrill's star. It is a Wolf Rayet star
and bubble rather than a planetary nebula as it is often cataloged.
Much of the red likely comes from nitrogen rather than hydrogen as it is
a WN 7 or WN 8 object. The N signifies strong nitrogen emission. Those
with 3 micron Ha and NII filters can test this.

This time I took it at my full resolution of 0.5" per pixel though the
night wasn't quite up to that. Still the result is much superior to the
first image. The nebula contains virtually no OIII emission. When I
took it in 2010 I was using my old Astrodon 1 filters. The green came
up empty of any hint of green emission though most other images of the
nebula show green. This puzzled me and others. Now that I have
generation 2 Astrodon filters I wanted to see if that changed anything.
It did slightly. Now I see a very very faint hint of green emission
but it is super weak. The blue of H beta came through in both but is
weak compared to the red. Likely because the red is mostly nitrogen
rather than hydrogen emission as it is a nitrogen class Wolf-Rayet star.
Still why did most images of this nebula show green when you looked at
the color channels. I found out that it was the way the saturation of
the image was done. If it was done after combining with the initial
color data then pushed to normal levels it showed green that wasn't
really there. If the saturation was done totally in the RGB combine and
not changed once combined the green vanished -- too much, it turned
black rather than staying at background levels. This time I did some
push in RGB and some after the combine. Thus there is some green if you
look at the posted image but that wasn't there in the original color
data. It's an artifact of how the color was combined. I'm going to
have to somehow download a copy of Pix Insight (takes hours on my slow
internet) and see if it handles this more correctly than I and
apparently others handle it in Photoshop. It will be an interesting test.

Now for the other reason for retaking this one. After I posted my image
Stefan Lilge, who often posts here, took the same field in narrow band
and discovered a small uncatalogued planetary image. He checked my
first image and it was there though I'd not noticed it. Not nearly as
nicely seen as it was in his image but it did confirm he found something
real. I then contacted Sakib Rasool who got a pro to image it with the
2.1 meter KPNO telescope. It was released at a conference last week so
I'm now free to cover it. The object is at 19h 12m 10.3s +16d 46'
35.6". That is in the lower left part of my image above and left of a
bright (not the brightest) pair of blue stars. There's a field star
that blocked much of the planetary in my LRGB image. Stefan's
narrowband image dims the star making the nebula more visible. I tried
to tone it down in this image but wasn't all that successful. Stefan's
discovery image can be seen at
http://ccd-astronomy.de/temp8/Sh2-80...ourcropgut.jpg .
Orientation is about the same as mine so it too is to the lower left.
Only his field is smaller so it by the only bright pair of blue stars.
The offending star on the right edge of the ring is quite faint in
narrow band images. Somehow the Kitt Peak image doesn't even show it
and severely dims the other stars in the field, completely hiding many
in my image making a comparison hard. The planetary is now known as
Li1. Li for Lilge of course. That's his only planetary so I've now
completed my first catalog! Small as it is. When I took the second
image I'd hoped to pick up the central star but failed. Nor is it seen
in the Kitt Peak image though it has greatly suppressed stars so that
isn't surprising I suppose. Odd they left in their hot pixels.

Ironically I am always harping on "Know what's in your image". I failed
in this case, fortunately Stefan didn't and it is Li1 rather than Jo1.
I've attached the poster from the conference showing all 37 candidates
(greatly reduced to meet size limits) and a full size crop of Li1 from
the poster. Note his discovery was made through the severe light
pollution of his central Berlin balcony! That shows his great skills as
a astrophotographer!

14" LX200R @ f/10, L=8x20' RGB=2x10'x2, STL-11000XM, Paramount ME

My image has been cropped from 4008x2672 to 3500x2500 as the news server
won't accept larger images. Posted in two parts as the news server
refused it with all 4 attachments.

Rick
--
Prefix is correct. Domain is arvig dot net

Mighty image Rick. Might be the best image of Lilge1 for some time :-)

First of all a big "thank you" for the confirmation image and your help in
getting in touch with the "right" people as I didn't really know what to do
with my discovery.
In case anyone wonders why this nebula was not discovered earlier here is a
link to the DSS II:
http://stdatu.stsci.edu/cgi-bin/dss_search?v=poss2ukstu_red&r=19+12+10.365&d=%2B16 +46+36.47&e=J2000&h=4&w=4&f=gif&c=none&fov=NONE&v3 =
It looks like a star there, so it escaped the eyes of those who are skimming
the DSS for new objects.

I have done a reprocessed version of my original data with more pleasing
stars and a different crop:
http://ccd-astronomy.de/temp8/Sh2-80/Lilge1neugut.jpg

Big thanks also to Matthias Kronberger of "Deep Sky Hunters" fame, who was
contacted by Sakib Rasool and made it possible to get an image of this
object through the 2.1m KPNO telescope.
Here is the KPNO image (I have removed some hot pixels):
http://ccd-astronomy.de/temp8/Sh2-80..._OIII_KPNO.jpg
Credit: copyright NOAO/AURA/NSF
R = 1200s Ha
G,B: 1200s [OIII]
Observer: Dianner Harmer

I'll have to do a proper webpage, but till then some (now slightly outdated)
info can be found at
http://ccd-astronomy.de/temp8/Sh2-80/Lilge1.htm

The new nebula was presented (along with others) by Matthias Kronberger at
the ASYMMETRICAL PLANETARY NEBULAE VI meeting in Mexico last week.

Stefan


"Rick Johnson" schrieb im Newsbeitrag
...

I'll get to the new planetary in a bit first SH2-80.

This is a retake of SH2-80 aka Merrill's star. It is a Wolf Rayet star
and bubble rather than a planetary nebula as it is often cataloged.
Much of the red likely comes from nitrogen rather than hydrogen as it is
a WN 7 or WN 8 object. The N signifies strong nitrogen emission. Those
with 3 micron Ha and NII filters can test this.

This time I took it at my full resolution of 0.5" per pixel though the
night wasn't quite up to that. Still the result is much superior to the
first image. The nebula contains virtually no OIII emission. When I
took it in 2010 I was using my old Astrodon 1 filters. The green came
up empty of any hint of green emission though most other images of the
nebula show green. This puzzled me and others. Now that I have
generation 2 Astrodon filters I wanted to see if that changed anything.
It did slightly. Now I see a very very faint hint of green emission
but it is super weak. The blue of H beta came through in both but is
weak compared to the red. Likely because the red is mostly nitrogen
rather than hydrogen emission as it is a nitrogen class Wolf-Rayet star.
Still why did most images of this nebula show green when you looked at
the color channels. I found out that it was the way the saturation of
the image was done. If it was done after combining with the initial
color data then pushed to normal levels it showed green that wasn't
really there. If the saturation was done totally in the RGB combine and
not changed once combined the green vanished -- too much, it turned
black rather than staying at background levels. This time I did some
push in RGB and some after the combine. Thus there is some green if you
look at the posted image but that wasn't there in the original color
data. It's an artifact of how the color was combined. I'm going to
have to somehow download a copy of Pix Insight (takes hours on my slow
internet) and see if it handles this more correctly than I and
apparently others handle it in Photoshop. It will be an interesting test.

Now for the other reason for retaking this one. After I posted my image
Stefan Lilge, who often posts here, took the same field in narrow band
and discovered a small uncatalogued planetary image. He checked my
first image and it was there though I'd not noticed it. Not nearly as
nicely seen as it was in his image but it did confirm he found something
real. I then contacted Sakib Rasool who got a pro to image it with the
2.1 meter KPNO telescope. It was released at a conference last week so
I'm now free to cover it. The object is at 19h 12m 10.3s +16d 46'
35.6". That is in the lower left part of my image above and left of a
bright (not the brightest) pair of blue stars. There's a field star
that blocked much of the planetary in my LRGB image. Stefan's
narrowband image dims the star making the nebula more visible. I tried
to tone it down in this image but wasn't all that successful. Stefan's
discovery image can be seen at
http://ccd-astronomy.de/temp8/Sh2-80...ourcropgut.jpg .
Orientation is about the same as mine so it too is to the lower left.
Only his field is smaller so it by the only bright pair of blue stars.
The offending star on the right edge of the ring is quite faint in
narrow band images. Somehow the Kitt Peak image doesn't even show it
and severely dims the other stars in the field, completely hiding many
in my image making a comparison hard. The planetary is now known as
Li1. Li for Lilge of course. That's his only planetary so I've now
completed my first catalog! Small as it is. When I took the second
image I'd hoped to pick up the central star but failed. Nor is it seen
in the Kitt Peak image though it has greatly suppressed stars so that
isn't surprising I suppose. Odd they left in their hot pixels.

Ironically I am always harping on "Know what's in your image". I failed
in this case, fortunately Stefan didn't and it is Li1 rather than Jo1.
I've attached the poster from the conference showing all 37 candidates
(greatly reduced to meet size limits) and a full size crop of Li1 from
the poster. Note his discovery was made through the severe light
pollution of his central Berlin balcony! That shows his great skills as
a astrophotographer!

14" LX200R @ f/10, L=8x20' RGB=2x10'x2, STL-11000XM, Paramount ME

My image has been cropped from 4008x2672 to 3500x2500 as the news server
won't accept larger images. Posted in two parts as the news server
refused it with all 4 attachments.

Rick
--
Prefix is correct. Domain is arvig dot net