New Planetary Neb found

[astroron]

I read this on amastro:) and thought some of our more adventurous imagers
Might be interested in giving it a go at taking a picture:):thumbsup:

Several weeks ago, during a DSS survey of the outer Milky Way in Sagittarius, I
came across a new and bright (!) obvious planetary nebula candidate in the
vicinity of Barnard's Galaxy NGC 6822 which may be of interest for some of the
PN folks here on amastro.

Coordinates of the candidate are 19 37 43.77 -13 51 20, size is approx.
0.7'x0.45'. The appearance of the nebula on the (blue) DSS-I image suggests a
mild bipolar morphology; the red DSS-II image shows also a central star
candidate immediately N of a superimposed star. Nothing in SIMBAD or NED at this
position. VIZIER shows a double entry of the object in the LEDA catalogue of
Paturel et al. (LEDA 932285 and LEDA 932333) but the object is clearly a line
emitter and not a pair of (interacting) galaxies. There is no IRAS or radio
source present at this position, which is probably one of the reasons why the
object has remained unnoticed until now. The PN candidate is only 1.5 degrees
distant from NGC 6818 (2 degrees from NGC 6822) and easily found 6' N of the 7
mag star SAO 162831.

I managed to observe the object last week with my new 15" under good
transparency (ZLM ~ 6m,8 - 7m,0). Even without filter a very faint glow appeared
at the position of the PN candidate. An OIII filter boosted the visibility of
the object considerably and showed it as a roundish glow with approx. 20" size
that could be held easily with averted vision. I also tried to see the two lobes
individually but failed to do so, probably due the lack of contrast and the
faintness of the object. The total brightness of the object I estimate to be ~15
mag, so it should be possible seeing it with apertures of 12" or even less.

Clear skies!

Matthias

[Merlin66]

Ron,
The easy way to confirm would be to get a spectrum of the object....
that will soon show what it is!
Raise this on the spectroscope thread??

[renormalised]

Very interesting....had a look on various catalogues and couldn't see a thing.

[renormalised]

Just knocked up an image from the Digitised Sky Survey of the StScI consisting of POSS2UKSTU-IR (r), Red (g) and Blue (b) channels. It's FoV is 13.79' x 12.61'. It'll give you an idea of what it will look like. The PN is in the centre of the image.

[Enchilada]

Ron
Here is a close up image of the object. I agree it is not listed anywhere that I can see. It also looks amazingly bright for an unknown object
However I doubt if it is a planetary, as the infrared image (DSS2) shows no evidence of nebulosity at all. Planetary nebula are brightest in most cases in Hydrogen alpha. My own guess it is might be a number of interacting galaxies, in which a star just happens to be placed over the southern portion of the nebula. I have added an image below taken from the SERC/ER/DSS2 and the SERC/J?DSS1. (See http://aladin.u-strasbg.fr/alapre.pl?-c=19+37+24.0-13+51+51&button=RGB )

Else it could be a bipolar planetary nebula, a there are faint nebulosities roughly east-west (PA 60 or 70 degrees), This is easily seen in the negative version as attached below.

Interesting to see what occurs when this is investigated in more depth.

Cheers

[Enchilada]

Ron, these are actually the words of Matthias Kronberger, as it appeared at the amastro site. You should have quoted this as " ", as it reads as if it were your own words. (If it were you should have paraphrased it.) I.e.

"Several weeks ago, during a DSS survey of the outer Milky Way in Sagittarius, I came across a new and bright (!) obvious planetary nebula candidate in the vicinity of Barnard's Galaxy NGC 6822 which may be of interest for some of the PN folks here on amastro.

Coordinates of the candidate are 19 37 43.77 -13 51 20, size is approx.
0.7'x0.45'. The appearance of the nebula on the (blue) DSS-I image suggests a mild bipolar morphology; the red DSS-II image shows also a central star candidate immediately N of a superimposed star. Nothing in SIMBAD or NED at this position. VIZIER shows a double entry of the object in the LEDA catalogue of Paturel et al. (LEDA 932285 and LEDA 932333) but the object is clearly a line emitter and not a pair of (interacting) galaxies. There is no IRAS or radio source present at this position, which is probably one of the reasons why the object has remained unnoticed until now. The PN candidate is only 1.5 degrees distant from NGC 6818 (2 degrees from NGC 6822) and easily found 6' N of the 7 mag star SAO 162831.

I managed to observe the object last week with my new 15" under good
transparency (ZLM ~ 6m,8 - 7m,0). Even without filter a very faint glow appeared at the position of the PN candidate. An OIII filter boosted the visibility of the object considerably and showed it as a roundish glow with approx. 20" size that could be held easily with averted vision. I also tried to see the two lobes individually but failed to do so, probably due the lack of contrast and the faintness of the object. The total brightness of the object I estimate to be ~15 mag, so it should be possible seeing it with apertures of 12" or even less."

For clarity, also the general title here "New Planetary Nebula Found" is slightly incorrect, as no one has determined what it actually is. It would be better if it read some thing like "New Planetary Nebula Candidate Found."

Also Steve Gottlieb has observed this object in a 22-inch on 25th July. He visually finds "The overall size seemed roughly 20"x15". This is much smaller than the object imaged here.*

Again, thanks for the update here.

[renormalised]

The problem with it being a pair or cluster of interacting galaxies is that there's no absorption lines coming from the spectra being taken of the object. It's a pure line emitter, which would say that it's most likely a planetary nebula. Interacting galaxies tend to be both line emitters and have absorption features too. You have to remember that Ha is not in the infrared part of the spectrum, it's in the red (6533A or 656.3nm). Interacting galaxies tend to have a lot of Ha emissions as well as dust (IR), maser emissions from various molecular species and lots of radio emissions. This thing is quite as in the radio and doesn't appear in IRAS.

What would put it beyond doubt would be a determination of its Z number.

Anyone got a spectra from the object??

[Enchilada]

Totally agreed. That is why I said; "Interesting to see what occurs when this is investigated in more depth."

"Looks" certainly can be different from when the eventual "evidence" becomes available.

[renormalised]

Precisely. That's why I'd like to have Z determined so we have a good idea of how far away this thing is.

Needs a much larger scope to have a look at this.

[renormalised]

We may have a problem if this object is at the same distance as NGC6822 in true terms. Given the distance to NGC6822 (1.63 million ly), that would make the object 158 light years across (at 20"). Way too big for a planetary. It would actually be a large nebula...at least 5x the size of Orion. Not only that, it would have absorption lines. If it's a planetary, it's a lot closer. Maybe it's a planetary of a halo star or your normal run of the mill star in the Galaxy, but a long way off.

[DavidU]

Get Anthony Wesley to swing Hubble around again:thumbsup:

[renormalised]

Yeah...Anthony seems to have the ear of the big boys....may pay to slip them a few notes of "encouragement":P:P:D:D

[GrahamL]

well not really if you reads the first bit .. I.e

;)

thanks Ron :thumbsup:

[Enchilada]

I actually didn't read the amastro site before I read this post. So which was the first bit and which one was Ron's? I had to go the amastro to find out! While I am truly grateful for him pointing this out - especially with my own affinity to planetary nebulae - it remains very important to quote sources properly.

Matthias Kronberger has made the discovery here. He justifiably deserves the proper kudos and to accurately report what he has actually written. In the end, it should have been properly and honestly quoted. It was not.

So burn me in oil if you must...

[coldspace]

Thanks Ron for pointing it out, I understood your post clearly :thumbsup: .
Will give me another object to image with my gear.

Regards Matt.

[Rhino1980]

God some people pick on the small things... Jeez. I understood perfectly that it was someone else's words. Thanks Ron for pointing it out.

[seanliddelow]

I think hubble should investigate this:thumbsup:. Can amatuer astronomers submit proposals?

[astroron]

MY post STARTED WITH THESE WORDS,
I read this on amastro and thought some of our more adventurous imagers
Might be interested in giving it a go at taking a picture.

AND At the bottom it is clearly stated by the author

Clear Sky's

Matthias.


Cheers:thumbsup:

[seanliddelow]

Heres an extreme close up in the visible wavelengths......
http://server7.sky-map.org/imgcut?survey=DSS2&img_id=all&angle=0.0146484375&ra=19.628908862145426&de=-13.85563121966891&width=800&height=800&img_borders=&projection=tan&rotation=0.0&reverse=0&interpolation=bicubic&jpeg_quality=0.8&output_type=jpeg

And heres one in Ultra Violet
http://server7.sky-map.org/imgcut?survey=GALEX&img_id=all&angle=0.0146484375&ra=19.628907485724977&de=-13.855668725059932&x_shift=0&y_shift=0&width=800&height=800&projection=tan&rotation=0.0&reverse=0&img_borders&interpolation=bicubic&jpeg_quality=0.8&output_type=jpeg

The stars in the PN have been given designations but not the PN itself?
The nebula appears very prominant in the UV images.
Im searching for more in the DSS and maybe the SDSS sky surveys.

[renormalised]

You used to be able to submit imaging proposals. I don't know if you still can??

[renormalised]

Ah...there you go. In the UV, there appears to be a discreet point source in the centre of the area. If it's a PN then that would be the white dwarf remnant. Being that bright in the UV would also mean it's a fairly young neb and therefore quite small. It's giving off most of it's light in the UV which means it's surface temp could be anywhere upto 250-300000K.

[Rhino1980]

Ron don't worry about people who split fine hairs. They're as bad as people who sit and pick at typos and incorrect gramma where it it is plainly obvious what is meant. They clearly have nothing better to do than try to prove their superior intellect. Your post read fine to everyone else...

[Enchilada]

There is no needless picking here.

If you quote someone, you should give proper attribution. It has absolutely nothing to do with proving intellect nor in picking on errors.

If this original "...post read fine to everyone else..." then there is a serious problem here. Sadly, the originator of this thread actually did not write the majority of the text in the original introduction to this thread.

As said in the ISS Term of Service.

"Do not post copyrighted material. If you are posting something that includes material or images from another source or website, credit the original source and include only an excerpt with a link to the original article."

Sorry. Ron excerpted the whole text!

[Enchilada]

It could be a new planetary nebula that has just brightened up.

Look forward to see some spectra, as you've also said earlier.

Intriguing. Absolutely, no doubt. :thumbsup:

[seanliddelow]

It doesnt appear in uranometria 2000.0.
:)

[Dennis]

Here we go…the mag 4 Brisbane skies really made me work extremely hard for this one!:)

Tak Mewlon 180 F12 with x0.8 Reducer/Flattener operating at F9.6
SBIG ST7 CCD camera.
10 exposures of 15 minutes each, total duration 2 ½ hours.

The cropped inset is an enlarged view of the PN.

Cheers

Dennis

[renormalised]

Nice shot, Dennis:)

[Dennis]

From Sean’s post above (msg #19), I used the colour data from SKY-MAP.org and combined it with my (grossly enlarged) luminance data.

Colour data obtained from http://server7.sky-map.org/?locale=EN

Cheers

Dennis