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What is this, please?
Posted: Sun Aug 12, 2012 12:30 am
by owlice
This image was sent in by APOD viewer Peter Craven, who took it near Flagstaff on Monday, 7/30/12. The item of interest, shown in detail in the top image, was reported to be a fairly large meteor with a visible bow shock; this determination was made by an observatory scientist.
![527056_450183165021697_58168084_n.jpg](./download/file.php?id=7525&sid=609c1545999e05e990bb85aea6edd98d)
- 527056_450183165021697_58168084_n.jpg (8.39 KiB) Viewed 3257 times
I have reservations, in part because of
this APOD and its
subsequent discussion, the results of which are nicely summarized
here. I should think that there would be other eyewitness reports of such a meteor but haven't found any. The "bow shock" seems not quite right to me, and overall, I think this object looks suspiciously like a dragonfly. But I'm not an astronomer, don't play one on TV, don't know what this is, so ask...
What is this, please?
Re: What is this, please?
Posted: Mon Aug 27, 2012 11:34 am
by starsurfer
It looks a little like an internal lens reflection but then I'm not an expert!
Re: What is this, please?
Posted: Mon Aug 27, 2012 1:29 pm
by Beyond
I would tend to agree with the observatory scientist, although i've never seen a daytime meteor, or one with a bow-shock at night.
I've also never seen a white dragonfly.
Re: What is this, please?
Posted: Mon Aug 27, 2012 2:35 pm
by geckzilla
It's pointed directly at the sun... The sun is in the trees. It could easily be a lens flare that's shaped strangely because the trees are obscuring the sun more than is apparent.
Re: What is this, please?
Posted: Mon Aug 27, 2012 2:56 pm
by Chris Peterson
owlice wrote:This image was sent in by APOD viewer Peter Craven, who took it near Flagstaff on Monday, 7/30/12. The item of interest, shown in detail in the top image, was reported to be a fairly large meteor with a visible bow shock; this determination was made by an observatory scientist.
What is this, please?
I can't rule out it being a meteor, but suspect otherwise. To a non-telescopic camera, a meteor presents optically as a point source, and appears to have a finite width because of diffraction. This image doesn't appear bright enough to produce its apparent width. If it is a meteor, the ring around it is definitely not a bow shock, nor related to it in any way. Meteors are hypersonic, moving at least Mach 5, and typically much faster. You can't have a detached ring like that, or any interaction with the atmosphere so lateral and distant from the meteor head.
This is what a meteor bow shock looks like- very close and swept back. In addition, the shock is composed of incandescent gas and ablated material. At the height a meteor is burning (tens of kilometers) the air is extremely thin; you don't have enough material to show any visible structure except where it is hot enough to glow.
I think the most likely explanation is something other than a meteor- an odd contrail, perhaps (with the ring just being a coincidental bit of cloud structure), a nearby insect, or simply lens flare or some other internal reflection in the optics.
Re: What is this, please?
Posted: Mon Aug 27, 2012 3:56 pm
by Beyond
In other words... a U.P.O. -->Unidentified Pictural Object.
Re: What is this, please?
Posted: Mon Aug 27, 2012 4:09 pm
by neufer
- Hamlet, Prince of Denmark Act 4, Scene 4
HAMLET: Now, whether it be... some Craven scruple
. Of thinking too precisely on the event.. I do not know.
Re: What is this, please?
Posted: Mon Aug 27, 2012 7:20 pm
by Sesa
definitely a lensflare. I know this of hours of computer gaming (see, gaming is education
![Smile :)](./images/smilies/icon_smile.gif)
Re: What is this, please?
Posted: Mon Aug 27, 2012 7:46 pm
by alienrogo
As a proffessional graphic designer I woul say it's a lensflare. They appear on the diagonal line connencting light source and center of the image. In this case flare is exactly on the opposite side of the Sun regarding center of the view.
Re: What is this, please?
Posted: Mon Aug 27, 2012 7:49 pm
by yahchanan
> this determination was made by an observatory scientist.
You need a new scientist. Ask a photographer. We all know it is lens flare.
Yahchanan
Re: What is this, please?
Posted: Mon Aug 27, 2012 8:02 pm
by Chris Peterson
yahchanan.com wrote:You need a new scientist. Ask a photographer. We all know it is lens flare.
I'd be cautious about asserting what we "know". There is good reason to think it is lens flare, based on its appearance, color, and position. That would seem a sufficient assessment given the evidence available.
Re: What is this, please?
Posted: Mon Aug 27, 2012 8:26 pm
by teuben
looks like a lens flare. Compared to the picture center, it's exactly diametrically opposite that center. It's
shaped a bit odd, because of the interference with the trees, the light entering the camera directly from
the sun is being shaped by the trees/leaves.
Re: What is this, please?
Posted: Mon Aug 27, 2012 9:15 pm
by Jason Denbow
Did the photographer also see the object with the naked eye? That would rule out lens flare.
Re: What is this, please?
Posted: Mon Aug 27, 2012 9:24 pm
by manbuck
I'm both a photographer and a designer: the object is a lens flare caused by the photographer's extreme wide-angle lens being aimed towards the setting sun low in the shot; the actual optical flare itself is minimized by diffraction from the background trees and other foliage in the foreground.
Re: What is this, please?
Posted: Mon Aug 27, 2012 10:16 pm
by owlice
Jason Denbow wrote:Did the photographer also see the object with the naked eye? That would rule out lens flare.
No, he did not. He saw this only after he'd uploaded the images from the camera (Canon SX40 HS) to his computer.
Re: What is this, please?
Posted: Mon Aug 27, 2012 10:22 pm
by Jasper Farnsworthy
I'm not convinced it is a lens flare. If you draw a straight line from the tail of the object through its head the line does not intersect the sun, but appears to be above it. However, if the image was taken with a wide angle lens, the photo could be distorted which may account for the discrepancy.
Re: What is this, please?
Posted: Mon Aug 27, 2012 11:08 pm
by Chris Peterson
Jasper Farnsworthy wrote:I'm not convinced it is a lens flare. If you draw a straight line from the tail of the object through its head the line does not intersect the sun, but appears to be above it. However, if the image was taken with a wide angle lens, the photo could be distorted which may account for the discrepancy.
Lens flare from bright sources does not need to be centered around the optical axis of the lens, and doesn't need to point to the source. The object producing the flare doesn't even need to be in the field of view. All sorts of possible internal reflection paths exist.
Re: What is this, please?
Posted: Mon Aug 27, 2012 11:58 pm
by I.H.
Nothing to see here people, it's just a weather balloon.
Re: What is this, please?
Posted: Tue Aug 28, 2012 12:13 am
by herbraab
teuben wrote:looks like a lens flare. Compared to the picture center, it's exactly diametrically opposite that center.
I fully agree - lens flare.
Certainly not a meteor.
Cheers,
Herbert
Re: What is this, please?
Posted: Tue Aug 28, 2012 4:26 am
by peterjohncraven
Thank you all for your input.
To help you I can tell you I was not using a wide angle lens.
Dragonflies do occur around Flagstaff but only near standing water. At this location there is none. There are no white dragonflies here.
I have created lens flares with this camera. They have never looked like this being always larger and colored.
I was merely taking a photo of an after storm sky with no thought of meteors and the like but upon seeing the image on my computer there was something extraordinary here.
I hope this information is of help.