Big Flash observed near big dipper @18:58CET

I was looking at the sky, few clouds and a skinny moon, as I do often and I happend to catch this big flash. It lasted maybe half a second, or a second, I'm not quite sure when it started and when I spotted it. But what I do remember is, it was big. Well, big for the regular flashes I observe. And it happend right next to Dubhe of the big dipper. I looked the name of the star up, but I'm 100% confident it was there. I'm also pretty confident about the time. It was a few minutes to 19:00, best guess somewhere between minute 57-59. My location is near Heerlen in the south of the Netherlands.

I looked for a good two minutes to see a repeat, possibly on the move. But observed nothing, other then a satellite going east to west about 10-15 degrees below Dubhe. Big dipper was in the north east, with Dubhe being the highest up to the right and the handle pointing down to the left. The flash was just to the right of Dubhe, like right next to it. Thats why I got such a good sense of the size.
Dubhe is a pretty bright star in my light polluted sky, and while this flash was not very bright, it was big in size, like 20-30 times the diameter of Dubhe. It was a warm almost fuzzy light. Did not last long, 1 sec max. It looked almost like a square with round of edges, but thats just how it felt. The light was not bright or sharp or flashy. It was, well, fuzzy. Not blue, more white and a little yellow. I just got the distinct feeling this light was comming from far away.

Is it even possible to observe things from space like a supernova with the naked eye? Or is this propably something much closer to earth?

Sounds like the flash when a small meteor comes into the atmosphere....straight at you. Of course, it isn't probably going to hit you, that is way up, but gravity will cause the remnants of the meteor to be pulled straight down or in the case of dust left, float all over. I do not know if this is what you saw, but I have seen a flash like that many times and know what they are.

You can check to see if it was an iridium flare.

I keep seeing threads about mystery flashes and wonder if its anything to do with the Cygnus rubbish bin.

But on investigation its not, it's coming down later in the month after doing a couple of other bits and bobs.

Still, something to look out for.

There was one but it may have been earlier based on your time. close to 17:45.

Check flares info here

Ive seen the impressive lightshow an irridiumflare produces but you can clearly see it is moving as it flares, this flash was static.

Likely as not, RoadGravel pegged it. Iridium Flares have produced flashes in excess of -8 magnitude and that is BRIGHT!

Sadly, they will no longer be visible, as they are being phased out.

As a skywatcher, I'm quite sad this is the case, however human progress moves forward. I hope it does represent "progress'.

Iridium 5 was passing right near there but seems like a couple minutes later than you say:
www.heavens-above.com...

Other possibility is Envisat: www.heavens-above.com...

originally posted by: argentus
Likely as not, RoadGravel pegged it. Iridium Flares have produced flashes in excess of -8 magnitude and that is BRIGHT!

Sadly, they will no longer be visible, as they are being phased out.

As a skywatcher, I'm quite sad this is the case, however human progress moves forward. I hope it does represent "progress'.

RoadGravels' explanation is a good possible explanation, but so is Rickey Mouse's explanation another possible one.

There is such a thing as a meteor that is moving in a direction generally toward an observer, in which case the observer would not see the long streak of a tail, but rather that streak would be foreshortened.

If it's moving "just in the right direction", that foreshortening could be extreme, and all the observer would sees is a stationary flash.

You called it a flash.....I see em all the time and have cataloged em

Now Harvard scientists are modifying the weather right now....Try In to freeze the North a little....

True story, Also I have a pvs 14 and an Armasight thingy triple snooper

And below the Big Ripper is a spot of renown for flashes and the location of the home planet of some purported travelers, I forget

That's what caught my attention ........special watched area....4 to 7 degrees below.....somthin like that

You guys his gotta get a pvs 14.....with a Pinnacle tube......see your first triangle craft at night in two outings....2 hours each....

I have witnessed a flashing object near the big dipper for the last five nights (Sep-11-2019 through Sep-15-2019), between approximately 20:15 and 20:30 hrs PDT (UTC 8:00), at a position approximate to an intersection of one line through stars Alkaid and Mizar and the other line through Phecda and Megraz.

They occur in sets of two flashes. Each flash nearly instantaneous (you blink and you miss it), then the next flash maybe 3 to 5 seconds later, same location.

Not a plane, not an Iridium Flare. Very intense, bright white. These were also witnessed by my brother on the first night. We are both baffled.

I am north of Lake Tahoe in a relatively dark sky area. I have been staring at the night sky for over forty years and this is only the second thing I've seen that I can't explain (the first was a UFO when I was about 8, but that is a different story...)

Any thoughts?

originally posted by: burntdogg
Any thoughts?

Yes.

I have been observing these flashes for many years now, and in most cases they are caused by fast spinning space-junk, although there are likely also flashes from operational satellites.

Space-junk has been building up at an almost exponential rate in recent years, and it does not take a huge piece to reflect enough sun light for the object to be visible from the ground. Major contributions to SJ population have been from the Anti-Satellite weapon tests and from the collision of IRIDIUM 33 and COSMOS 2251 a few years back now.

There is also a near constant stream of satellites being launched into orbit now, so spent rocket boosters etc can also be observed, although I don't think they have the super-reflective surfaces which cause the brightest flashes (I could be wrong).

Tracking and identification is fairly straight forward...

However, you will need a camera + appropriate lens + tripod ($50 for a basic, but better to spend double and get a good solid pod if you think you want to do more photography - eg. google "055PROB tripod" or "055XPROB tripod") and a few other accessories (memory card, remote release with "running shutter" lock - $10 for both new - buy a Chinese release from ebay). It can be done on a fairly budget if you buy used gear. The lens is more important than the camera, and a good one to choose is the Samyang/Rokinon 24mm F1.4 ($200 used aprox.), although QC on these is not great and the stars may not be perfect in the corners of the frame when @ max. aperture, so if you want pretty pics of stars, you may be better of looking for another 24/1.4. It would still work for this project though.

If on a tight budget, something as old (and cheap) as a Canon 20D (less that $50 used for a low use body I would think by now), will do the job, but I wouldn't go older than that. A Canon 70D is a great choice if you want to spend a bit more ($350-400 I think) and you can use it to record HD footage, although this feature works best in good light and is near useless for footage of stars. It is a great camera though, and very good value for money.

If money is not a huge issue, and you want a camera that will record UHD footage of the stars, and satellites too (although it might not work well for this project as the footage is quite noisy and flashes would likely be lost/hard to spot, but you can still use still images which are much less noisy), then a Sony A7S would be good bang for your buck, used @ around $500 or $600 I would guess currently.

You might be able to get away without the camera if you are close to your PC or laptop, but getting an image of the object will create a permanent record, and give you a more positive confirmation of the identity. There can be multiple objects in the same part of sky, some or all below the threshold of naked eye visibility, so you can only be truly sure of an identification if you catch at least one glint from the object, but preferably some of the trail which it leaves as well, if any is visible to the camera.

Here is what you do:

1/ Set up camera indoors (RAW image quality, manual mode, daylight white balance, continuous shooting mode, set the time as accurate as you can get it using your PC's clock - turn off ALL noise reduction), and focus using the stars (it's a bit of an art, and you should read up on it) once you get outdoors. Take test exposures using max. aperture on the lens and using ISO 800 (20D) or ISO 1600 or 32000 on more recent bodies. Keep them short, between 6-10 seconds ideally, but you might need less than that to keep the sky from washing out if you are somewhere light polluted, otherwise it will be hard to see any trails left by objects. You may need to experiment a little to get it right.

2/ Observe, and wait... you might want to cover your camera, to keep it warm and dew free till you need it, but be careful not touch the focusing ring!

3/ When you see a flash, uncover/turn on, and point the camera as close to the flash as you can, without any delay (practice beforehand). Set the running lock to the on position and the camera will take exposures till you disengage the lock (this works for Canons, not sure about others). Give it a minute or two, and hopefully you have imaged some flashes or a trail of the object.

4/ Once you get back in and you've off loaded the images to your hard drive, zoom into each image and check for trails, ideally with software which will let you flick between the images without delays to load them - this makes it easier to spot small changes between images. You may need to process/convert the images from RAW format to something like jpeg first.

5/ If you found a trail/glint in an image, start up Sellarium, and load the Satellite plugin in the solar system editor.

6/ Stellarium should load up a bunch of satellites, but make sure the data has been updated, if not, ask it to do so. Then check the appropriate part of sky during the time of the exposures you took to see if any objects pass through. You'll find the correct timing of the exposure in the image file's EXIF data.

7/ Assuming the last step did not reveal any candidates, go to celestrak TLE data and download all the data you can from the "Special-Interest Satellites" section. You'll have to cut and paste the "debris" sets into separate .TXT files, and load them one at a time, manually into Stellarium. Go easy, especially if have an older PC, and make sure you remove one lot of debris before loading up another, unless you have a very fast PC, or Stellarium can slow down (and possibly crash).

That's basically it. Just make sure you always have up to date TLEs. I did used to have a thread with actual examples (using different software though), but the images have since been lost.

I no longer bother to identify satellites/junk (unless I have a good reason) as I am usually trying to image natural phenomena such as meteors, and satellites/junk in an image is a PITA as there is so much of it, and even a small trail detracts from an image, but I do still catch plenty of junk flashes and trails.

You can get a good idea of the type of things you will capture with a 24/1.4 lens with this UHD timelapse I've uploaded, although it was made using a full frame camera, so a little wider FOV than when using a crop sensor DSLR like the 20D or 70D: vimeo.com

Please feel free to ask if you get stuck anywhere, and let us know how you (or anyone else who want to give it a try) get on.

a reply to: FireballStorm
Thank you for the response Fireball - very in-depth and practical.
One of my first assumptions was a rotating satellite, but I found that the recurrence of the flash over a five day period to be beyond chance of catching sight of a wayward junk satellite.

My wife happens to be a professional portrait photographer, so I may just have all the equipment you mentioned - I will need to verify the lens (and my permission to borrow).

If and when and I give your process a go I will dutifully report my findings.

Thanks again.

a reply to: FireballStorm
Your time-lapse video is rather breathtaking by the way. Thanks for sharing that.

Nano sail D satellite. I have seen this one before. It can light up a large area depending on the sun's reflection.

originally posted by: burntdogg
a reply to: FireballStorm
Thank you for the response Fireball - very in-depth and practical.
One of my first assumptions was a rotating satellite, but I found that the recurrence of the flash over a five day period to be beyond chance of catching sight of a wayward junk satellite.

It may well be that you were seeing different objects. There is a lot of stuff whizzing around up there!

originally posted by: burntdogg
My wife happens to be a professional portrait photographer, so I may just have all the equipment you mentioned - I will need to verify the lens (and my permission to borrow).

It sounds like you may be all set. Most modern pro-level camera bodies will be suitable. It's possible the lens may be the only sticking point, since many photographers use zooms, and they would be too slow for a project like this. You should be OK if your wife has a 35/1.4 lens or even 50/1.8, but these will leave more margin for error if you are trying to find the flash in the sky due to the narrower FOV, unless used on a full frame sensor camera - however they do gather more light, and so should pick up fainter objects than the 24/1.4. Exposures will need to be kept shorter though, especially if light pollution is a problem where you are. This project may be a non-starter if light pollution is significant where you are - you may need to find a site away from lights. Even the moon will hinder your efforts, so check when the moon is in the sky (Stellarium) before you plan anything.

If your wife does not have a fast wide/normal prime lens, consider renting one.

One last point: If your camera does get cold after a significant time under the stars, once you are done, remove the memory card, and wipe down the camera if there is any dew. Then put the camera/lens in an airtight plastic bag before you bring it indoors, and leave it for an hour or two to warm up before removing. If you do not do this, the camera will attract condensation which may damage it.

Also, if you prefer, rather than just covering the camera and leaving it turned off while you wait, you could leave it running (hoping it is pointed the right way if a flash materializes) and point in another direction if you see a flash elsewhere in the sky. It's quite easy to make a timelapse like mine this way, unless you move the camera, which would spoil it somewhat. The trouble is that batteries drain quickly in the cold, and your lens may dew up. There are ways around these problems however - eg. spare battery, although AC adapter is better (no need to stop), and a chemical hand-warmer pack taped under the front element of the lens to ward off dew. Higher capacity memory card is a good idea too - 32gb should do in most cases.

This is basically the same technique which I use to image meteor showers/fireballs, apart from using slightly longer exposures (when possible), so you might like to give that a try at some point, if the astro-photography bug bites you. Be warned - photographing the stars/night sky can become quite addictive!

originally posted by: burntdogg
a reply to: FireballStorm
Your time-lapse video is rather breathtaking by the way. Thanks for sharing that.

Thank you. You're welcome!

If you liked that one, another (from the same night, using another camera) can be found here.

I think timelapses made with a fast lens are great illustration of just what most people are missing up there - at times it looks like an exchange of fire during a battle! Unfortunately most people stop down their lenses in order to get better stars in the corners, so most timelapses don't catch the fainter stuff, but lenses are getting/have gotten better, and these type of timelapses are starting to become more common now.

originally posted by: mugger
Nano sail D satellite. I have seen this one before. It can light up a large area depending on the sun's reflection.

I did catch an unusually large and seemingly "greenish" flash high in the sky a week or two back, so that might explain it - or perhaps a point-fireball. I'll be keeping an eye out for it in future either way. Thanks for the tip!

I wonder how many of these flashes need to happen before normies take it seriously.