The Witch Head Nebula (11 Dec 2006)

[cjet]

Hello!

Can anybody explain what the red spot on the image ic2118_dss_big.jpg at approximate coordinates 2880,970 is?

regards,
cjet

[Andy Wade]

Hello!

Can anybody explain what the red spot on the image ic2118_dss_big.jpg at approximate coordinates 2880,970 is?

regards,
cjet

http://antwrp.gsfc.nasa.gov/apod/ap061211.html

I'd say it was a digital artefact.
There's a similar one, slightly less bright and slightly lower, the same distance from the side of the image, but on the opposite side.
When any image is digitised you can get things like this appearing. Pixels are assigned colours and sometimes they appear to make a pattern, or something that isn't really there.
There's also what looks like a bit of orange thread at about 7.30 (on a clock face) from the first red dot (there are two bluish galaxies, one with spiral arms, just to the left of this 'orange thread') I'm sure that isn't really floating about in space.

Hey I just realised that the 'Witch' is looking at all these 'anomalies', maybe she's puzzled about them too...

[BMAONE23]

there is also a string thing at about 7:30 with respect to the red spot that the witch is looking at

[Andy Wade]

there is also a string thing at about 7:30 with respect to the red spot that the witch is looking at

LOL. I said that, didn't I? That's the bit of 'orange thread' I was referring to. This must be an artefact of the digital process.
Actually when you look closely, there are loads of 'little blips' in this picture. I'm not on broadband, so I don't generally download the bigger pictures, so I don't usually see them in such great detail.
There are so many galaxies in it too. And we wonder if there's intelligent life elsewhere? Silly question really, of course there is, we'll just never get to meet them as they're so far away.

[astro_uk]

Its from the Digitized sky survey, which is based on photographic plates, so the things you are describing
are most likely bits of dust or hair or scratches on the plate.

The plates have to be digitized by a a machine that essentially scans them, anything on the plate at the time that happens also ends up in the image.

Thank heaven for CCDs now.

[BMAONE23]

Its from the Digitized sky survey, which is based on photographic plates, so the things you are describing
are most likely bits of dust or hair or scratches on the plate.

The plates have to be digitized by a a machine that essentially scans them, anything on the plate at the time that happens also ends up in the image.

Thank heaven for CCDs now.

Gee,
And I thought maybe it was proof of String Theory, A galactic superstring

[cjet]

Thanks for all the replies! Thought I've found something that was not only dirt on the lens but it seems I was wrong

[NoelC]

Bear in mind I made this Witch Head image from IR, Red, and Blue exposures.

Looking at the original plate data, I'd say it is unlikely the spot at (2880,970) was dust or a plate defect, as its shape is round with a bright center, and its sharpness seems to resemble that of the other objects in the image. Notably it appears only in the infrared plate exposure, and so is colored deep red in the final image. It is possible it is an IR-only source, or it may be a phenomenon that showed up only when the IR plate was being exposed. Notably it's got a bit more of a halo around it than the surrounding objects. It does not appear on sky charts going down to magnitude 15 stars.

Keep in mind these DSS plates were exposed many years apart!

I actually removed most of the obvious plate defects during processing, including the shadow of a small thread or two. I missed a few, including that orange thread. Some of the dust/defects were on the plate when exposed (these show up as dark spots), and some during the scanning process (light spots).

Here are the IR, red, and blue exposures of the area containing this object, at full resolution from the plates, and without defects removed from the plate data. The object in question is at dead center. Judge for yourself.

IR exposure, November 12, 1987, UK Schmidt telescope:


Red exposure, October 21, 1993, UK Schmidt telescope:


Blue exposure, November 17, 1984, UK Schmidt telescope:


Portion of sky chart showing stars as dim as magnitude 15:


So... I'm thinking this [infra]red spot could be a true discovery. Good eye, cjet!

-Noel

[Doum]

Quote from NoelC:

"So... I'm thinking this [infra]red spot could be a true discovery. Good eye, cjet! "

Now if it is real, can it be a brown dwarf star. Hmm, it might be interesting to take more picture to see if it is. And if it is, then to us seeing it from here might mean it is in our solar system but far away (Few weeks light years distance!). Just having fun speculating.

[cjet]

Wow, since I'm studying physics at the university -yet without any clue about our universe- this is now getting more and more interesting to me.

Since I think this is sometimes a crazy planet we're living on, I don't think I can keep myself up-to-date if this spot will be investigated any further - Can I?

Special thanks for your answers, NoelC and Doum, they somehow keep me studying as I already thought I'd quit studies.

regards, the student

[Doum]

Hey cjet,

I was doing wild speculation. It can also be a new star being born and it didnt have time to blow away the cloud gas surounding it. But the gas being heated by it we can see the infrared of the gas. May be it can be a far galaxy (The redshift measurement could tell if it is something far.). As you can see there are many possibility and to say what it is, it will need to be study. Having it being a brown dwarf star would be more fun . Having it in our solar system might bring chaos with time . Here i stop doing wild speculation. Time will tell. Or another member.