Small Green Anomaly with Blue Trail (Night Sky Photography) [Lens Flare/Reflection]


I took this photo a couple of years ago and just stumbled across it again. I thought I'd post to see if anybody else has ever captured/identified something similar, and also to contribute the image for any potential future discussions of similar photos.

Camera and settings: RX100, at 10mm (28mm full-frame equivalent), 30 second exposure, f2.2, ISO 125.
Date and location: Brisbane, Australia, Feb 4th 2013 at 3:22 AM. Camera was angled toward the Southern Cross (seen to the upper right of the middle of the photo).

I have captured commercial planes at night before and none have looked like this. I'd expect that even a high altitude military jet would streak more than this over such a long exposure? The 30 second star trails can be seen when zoomed. I didn't notice anything with my naked eye at the time, however the stars were also much dimmer to the naked eye. The contrast and brightness were increased by the long exposure, and then boosted even further digitally after noticing the blue/green anomaly.

1) Lucky timing on a faint meteor or space junk burning up? Could the green and blue indicate copper?
2) Plane/afterburner, rocket, or satellite positioning at high altitude?
3) Comet? However, I posted this on an astronomy forum when the photo was taken and any known comets were ruled out by users with astronomy software and greater knowledge than I. The thread then remained as unidentified.
4) Lens flare?

1_Original_ DSC00526.jpg

Increased brightness.

100% crop.

Crude constellation guide to help anybody trying to orientate themselves on star/comet maps.
4_StarGuide_ DSC00526.jpg
Last edited:
Were there any lights near where you were shooting? I could be lens flare.

I did consider that. There were no significant lights that I noticed, I also took a couple of other photos with a tripod from the exact same location (I was attempting to photograph the incoming cloud cover/streaks), sadly thick clouds are covering that section of the sky in my other shots and then I called it a night (I hadn't noticed the anomaly until sorting the files on my computer). The other photos did not show anything "in front" of the clouds, so I had thought lens flare or sensor/lens faults would be unlikely.

However, I think you might be on to something as I just realised I don't recall if the moon was visible at the time (out of shot). Perhaps even one of the stars in the image could cause this? Additionally, if the cloud cover blocked out the moon it would explain why the effect was not persistent in other shots.

I just tried searching for lens flare in the night sky, this is somewhat similar:


It'd be great if somebody has a more similar example or could replicate the results? Additionally if somebody has access to astronomy software they could perhaps kindly see if the moon was up at the time?
Last edited:
Did you take any other photos before or after this one?

The blue and green colors seem very common for a comet.

But comets hardly move in the sky, and rockets move a lot. So two photos would be very helpful.
Did you take any other photos before or after this one?

The blue and green colors seem very common for a comet.

But comets hardly move in the sky, and rockets move a lot. So two photos would be very helpful.

Was just going to say that it looked like a comet... Ive been doing some digging around and I cant find any references anywhere to a comet on Feb 4 2013. Its possible that perhaps you discovered a new one, or it may be a comet thats too small for the average joe to see, so no one really talks about it (which I cant see happening.. star gazers go nuts for these things). I agree with Mick that if you had any concurrent photos taken before and/or after the ones you posted would help a lot. We might be able to determine a speed if its not a comet, or narrow down what comet it IS given the trajectory and how long it takes to cross the sky. Personally (and this is just the star nerd in me) I hope you found a new one.
Did you take any other photos before or after this one?
Unfortunately, not of the subject in question. All my photos before and after had that section of sky covered by thick clouds or were facing in different directions. I didn't notice what I'd accidentally captured until examining the photos later.

I have been exploring a few options, but haven't been able to come to any kind of conclusions.

For the sake of being exhaustive with all currently available astronomical information and any suggested theories, I have detailed some data below. The moon was in fact just out of frame at the time of the photo. Could it have reflected off the other internal side of the barrel?

This satellite is pretty close to the "object zone" and within a few minutes of the time frame. The arrow shows the distance the satellite travelled over the 30 second exposure and also shown are the star trails for the same time frame. Interestingly, the satellite has a perpendicular motion to the star trails exactly as in the photograph. However, there's absolutely no explanation I can fathom for how a satellite could possibly show any of the visual characteristics similar to what's in the photo.

These two comets appear to be the only ones nearby in my (potentially limited/outdated) dataset. I suspect the predictions for their positions are accurate. Hyakutake appears to have a green and blue colouration and a short tail in some photos, but I'm yet to find one stated to be taken with similar camera settings/gear for comparison.

Finally, there's this nearby meteor shower. Again, I have not yet sourced a similar style photo of the event and would generally expect meteors to have much longer trails. Perhaps this meteor was just broke up and then burnt out quickly? Otherwise it's possible it had only just began as the 30 second exposure was ending. There's also still the possibility of it simply being a random meteor or space junk not part of any bigger documented event.

Well that's all the nearby astronomical information I have so far. I'm far too novice at this to make any conclusions, but maybe this data will assist somebody else more experienced to provide some assistance. Also, if anybody has the knowledge to eliminate or elaborate on any rocket/afterburner theories that would be helpful too.
Last edited:
Here is something about a comet around that time.

External Quote:

2013 could turn out to be a comet bonanza. No fewer than three of these long-tailed beauties are expected to brighten to naked eye visibility. Already Comet C/2011 L4 PANSTARRS has cracked that barrier. Sky watchers in Australia have watched it grow from a telescopic smudge to a beautiful binocular sight low above the horizon at both dusk and dawn. A few have even spotted it without optical aid in the past week. Excited reports of a bright, fan-shaped dust tail two full moon diameters long whet our appetite for what’s to come.

Recent brightness estimates indicate that the comet could be experiencing a surge or “second wind” after plateauing in brightness the past few weeks. If the current trend continues, PanSTARRS might reach 1st or 2nd magnitude or a little brighter than the stars of the Big Dipper when it first becomes visible to northern hemisphere sky watchers around March 7.
I do like the idea of a comet, but is it likely to achieve such a prominent vivid image merely with a pocket camera at 28mm full-frame equivalent?

I've messaged a couple of experts seeking further information and perhaps more accurate/recorded data of comet positions and directions at the time. I'll post any relevant correspondence here with their permission.
but is it likely to achieve such a prominent vivid image
maybe it's not vivid at all. the camera maybe did weird weird things to compensate?? when you blow up the original 200%, not only are the colors somewhat ridiculous but the "tail" shape makes no sense.

Hope you find out and can share!
  • Like
Reactions: 386
Below is astronomy blogger, Astro Bob's response to the image. (
External Quote:
The green looks a bit like a comet, but the blue's all wrong. No comet I've ever seen looked like that in shape or color. My first thought was venting from a distant third stage rocket from a recent launch. Perhaps you could look up what rockets may have launched that day or the day before. Otherwise it looks suspiciously like lens flare - especially the colors.
The closest (successful) launches I can find are a few days earlier.

Back to the lens flare theory I guess. It is the right shape for it. Perhaps the moon reflecting off the rim of the opposite side of the lens and then reflecting back into the lens?
did he happen to mention why there is so much color in your stars?

No, but I suspect it has to do with the camera's automatic jpeg profiles and original importing software, combined with the 30 second exposure, conditions on that night, white balance, and the various noise reductions the camera uses for long exposures. This was back when I likely still had a number of the settings on auto. I strictly shoot in RAW and manual now, and have upgraded to Photoshop from Sony's photo management software, hopefully my next anomaly will be captured more scientifically and examined more immediately. The colours on the stars are correct to each star however, it hasn't just randomly fabricated the sky.

I just found this photo on Google image search.

The flare at the bottom of the image is starting to look rather familiar, just imagine what a much fainter and smaller light source but burning in for 30 seconds might look like. However, I've never experienced any lens flare issues at night before or since (with the same lens/camera). if I get a chance, I'll try to replicate the results tonight with the same camera, a torch, and some bits of card.
Last edited:
I would say this is almost certainly lens flare.

For something to appear this big and bright in a full-frame photo, it would surely be noticeable with the naked eye, even if not by you then by plenty of other astronomers.

The shape looks perfect for lens flare, and its axis appears to pass through or very close to the centre of the lens, which is usually the case with lens flare.

Notice also how the brightest part of the sky is in the opposite corner to the mystery object (lower right) suggesting that there may be a bright light source off-camera in that direction.

This screen grab is just a quick one from my phone to show the centre, as I don't have access to a computer right now.

Notice also how the brightest part of the sky is in the opposite corner to the mystery object (lower right) suggesting that there may be a bright light source off-camera in that direction.

I believed that was just cloud cover, it was a dark location and surrounding lights were taken into consideration, but perhaps during the long exposure somebody drove past (there was a perpendicular road about 30m behind me) and maybe their lights reflected off something nearby without me consciously acknowledging it. The brief intense light while not present long enough to overexpose the image could still have this effect on the final image obviously.
I'll try to replicate the results tonight with the same camera, a torch, and some bits of card.
With a bit of messing about I've been able to replicate the results very accurately! You can see where the narrow light source is off to the right. I'm still not sure what the light source was in my original image, but my best guess is it must have been a passing car as described in my previous post.

I could have saved a lot of time if this was the first thing I tried, haha. Oh well, I learned how to track comets and satellites and a bunch of other cool things about stars and such, so time well spent in my opinion :). Also, hopefully this thread comes in handy for somebody else in the future.



Thanks to everybody for their time and effort!
quick question, is that a 30 second exposure. or did it happen with just a regular camera click too?

It wasn't at the same shutter speed because I was compensating to achieve a similar level of exposure to the original flare while using my substituted light source which had an unrelated brightness to the original unknown source. Shutter speed wont effect the flare as long as the brightness of the light source is also equally adjusted. However, aperture alters the flare, and focal length dramatically alters the flare (with some lenses at least).

This is as close as I could replicate the original at 10mm (crop sensor) or "1.0x zoom" - which is the focal length that was used in the original photo.

This is as close as I could replicate the original after merely adjusting the focal length to ~11mm (1.1x zoom). I also had to position the light source more directly into the lens to get the flare to occur at all (at any shutter speed or ISO). The resulting flare is suddenly looking a whole lot less mysterious/astronomical, haha.

This was my best effort to achieve the same flare with the lens at ~12mm (1.2x zoom). Again, I had to position the light even further into the lens to get the flare to occur.

This demonstrates the potentially dramatic effect of focal length when attempting to recreate lens flare anomalies. However, this is merely an example with this specific lens. The exact values used and effects achieved should not be regarded as universal. Different lens designs/coatings/groupings will behave uniquely.
Last edited: