Discussion of APOD 15 August 2007: Mysterious Streaks

[Chris Peterson]

I submit: Location Beynam near Ankara, Time: 4:00 - 7:00 local time.
and I receive this in Calsky.com:

4:23:26 Iridium 35, -1,9 mag (in Orion)
4:32:45 Iridium 97, -4,7 mag (in Orion, spare satellite, time and mag can be inaccurate)
4:42:04 Iridium 5, -2,6 mag (in Orion)
4:51:19 Iridium 6, +1,2 mag (in Orion)

Well, it sounds good. But I can't make any of that work. Could you provide more details where you got these numbers? Taking the location as 39°42'N, 32°54'E, I don't see any indication that these satellites were in Orion between 0400 and 0600 on August 12. I checked with Calsky, Heavens Above, and with the satellite propagator in TheSky. What I got from the last was that Iridium 90 passed above Orion at 0455, very close to the uppermost very faint streak (there was no flare). None of the other four streaks correspond with any Iridium satellites at all.

Am I doing something wrong? Are you? Some clarification would be appreciated.

[MaG]

OK

1) Check location. I searched: Turkey, than Beynam.. it gives me:
Beynam, Turkey
WGS84: Lon: +32d53m45.0s Lat: +39d41m21.0s Alt: 1324m

2) Check date and time: Date 12. 8. 2007, time - the best is maybe UTC, so than you must enter 0:15 for beginning and 1 hour span (to 1:15 UTC)..

And then you must see these 4(!) flares. The fifth was very weak and Iridium 7 you can fing in bright satellites section within 9 mag satellites in Orion.


Observer Site Beynam, Turkey
WGS84: Lon: +32d53m45.0s Lat: +39d41m21.0s Alt: 1324m
All times in GMT
0h23m26s Iridium 35Iridium 35 Flare from MMA0 (Front antenna) Magnitude=-1.9mag
Azimuth= 99.9° E altitude= 6.2° in constellation Orion
RA= 5h10.9m Dec= -3°35' distance=2642km
Flare angle=0.63° to flare center: distance=215.4km, azimuth=101.0° E ; →MapIt longitude=35.347° E latitude=+39.294° (WGS84)
Satellite above: longitude=58.419° E latitude=+33.040° height above Earth=781.3km distance to satellite=2642.5km

0h32m45s Iridium 97Iridium 97 Flare from MMA0 (Front antenna) Magnitude=-4.7mag
Azimuth=100.5° E altitude= 8.5° in constellation Orion
RA= 5h11.8m Dec= -2°29' distance=2444km
Flare angle=0.20° to flare center: distance=56.0km, azimuth=101.4° ESE; →MapIt longitude=33.535° E latitude=+39.588° (WGS84)
Satellite above: longitude=56.379° E latitude=+33.625° height above Earth=780.3km distance to satellite=2444.0km
This is a spare satellite or its status is unknown. Brightness estimate may be unreliable and flare time accurate to a few seconds.

0h42m04s Iridium 5Iridium 5 Flare from MMA0 (Front antenna) Magnitude=-2.6mag
Azimuth=101.5° ESE altitude= 11.3° in constellation Orion
RA= 5h10.0m Dec= -1°24' distance=2235km
Flare angle=0.56° to flare center: distance=123.5km, azimuth=282.1° WNW; →MapIt longitude=31.484° E latitude=+39.913° (WGS84)
Satellite above: longitude=54.124° E latitude=+34.123° height above Earth=781.6km distance to satellite=2234.9km

0h51m19s Iridium 6Iridium 6 Flare from MMA0 (Front antenna) Magnitude= 1.2mag
Azimuth=102.9° ESE altitude= 14.7° in constellation Orion
RA= 5h05.3m Dec= -0°13' distance=2014km
Flare angle=1.72° to flare center: distance=299.9km, azimuth=283.0° WNW; →MapIt longitude=29.461° E latitude=+40.248° (WGS84)
Satellite above: longitude=51.666° E latitude=+34.579° height above Earth=781.8km distance to satellite=2013.8km

[MaG]

As I can see now, I resolved one small mystery with second streak (the brightest, 2nd from bottom). As you can see, this flare is cutted in the left edge. Its simple. This flare occurs at 4:32:45 and typical flare last around 1 minute, so when the exposure was ended at 4:33, the flare did not end at this moment, and therefore is some cut in left edge (because this Iridium goes on the sky from right to the left..).

That is other good agreement with Iridium flare "theory" "explanation" or as you can name it 8)

[wildmaven]

In any case, there's no reason to think that there's anything more complicated going on here.

Which is why I posted my lens/filter scratch question. Sometimes the simplest of solutions is probably the most likely. As we are all interested in the search for knowledge, I don't think it would be too embarrassing for the author to say, "oopsy, I just took a look, and there are scratches there! How could I have not thought about that in the first place?"

[Chris Peterson]

1) Check location. I searched: Turkey, than Beynam.. it gives me:
Beynam, Turkey
WGS84: Lon: +32d53m45.0s Lat: +39d41m21.0s Alt: 1324m

2) Check date and time: Date 12. 8. 2007, time - the best is maybe UTC, so than you must enter 0:15 for beginning and 1 hour span (to 1:15 UTC)..

I think you've made a time error. Beynam is on EEST, which is UT+3. The images were collected between 0415 and 0515 local time. So that should be 0115 and 0215 UT. There are no flares reported. And even if you look at the earlier flares, all are well below Orion, while the streaks are all above it.

In the correct time frame, I found three candidate objects in very nearly the same locations as streaks. The top streak (very faint) could either be Iridium 90, or Cosmos 1660 (15821U), at 0456. The second streak from the top could be an SL-8 rocket body (21090U). Notably, neither of those shows much variation in intensity, as you'd expect.

That leaves the lower three streaks, which don't correspond with any cataloged satellites. Of course, not all satellites are cataloged. But three, through the same area, all flaring, seems unlikely in such a short interval. But so are three meteors. There's still some mystery here.

[Chris Peterson]

Which is why I posted my lens/filter scratch question. Sometimes the simplest of solutions is probably the most likely. :) As we are all interested in the search for knowledge, I don't think it would be too embarrassing for the author to say, "oopsy, I just took a look, and there are scratches there! How could I have not thought about that in the first place?" ;)

Unfortunately, these streaks look nothing like what you get on an image when a lens or filter is dirty or scratched. If you saw anything at all (unlikely), it would be parallel streaks around every bright point source in the image. There's no way that scratched optics could produce those three bright streaks (I'm pretty sure the top two are satellites) without there being bright sources in those spots to begin with, and without also producing a streak around the light on the hilltop and on the brighter stars.

[markgaither]

If you look closely you will notice there are more than 5 streaks in the image... they begin near the base of the photo and track toward the upper-left corner... at the point where the three brightest streaks are located they shift direction and begin tracking toward the upper-right corner of the image and fade off... I counted 7 streaks in the enlarged photo... I am not near my home computer and do not have access to Photoshop and cannot enhance the image to see if more streaks appear but I would venture to say that with enhancement more streaks would resolve...

I would have to say this is an aberation in the composite and originates from a reflected source (the lights on the hilltop)... most likely equipment or structure at the camera location... even as simple as a pair of reading glasses, drinking glass, or some other artifact.

[Chris Peterson]

If you look closely you will notice there are more than 5 streaks in the image... they begin near the base of the photo and track toward the upper-left corner... at the point where the three brightest streaks are located they shift direction and begin tracking toward the upper-right corner of the image and fade off... I counted 7 streaks in the enlarged photo... I am not near my home computer and do not have access to Photoshop and cannot enhance the image to see if more streaks appear but I would venture to say that with enhancement more streaks would resolve...

I don't see them. I tried stretching the image in PS, and still can only detect the 5 streaks. Maybe you can post an enhanced image when you get a chance, pointing out what you are seeing.

I would have to say this is an aberation in the composite and originates from a reflected source (the lights on the hilltop)... most likely equipment or structure at the camera location... even as simple as a pair of reading glasses, drinking glass, or some other artifact.

I can't think of any mechanism by which a local reflection could produce focused streaks at the focal plane.

[TheRedCello]

yay, my first post
anyway, those 'mystery streaks' in the August 15 picture look a lot like power lines to me. there is a bright spot on the horizon of the picture that looks like a spot light. if it is a spot light and not just a really bright planet or something like that then it's possible that the light could be hitting the possible powerlines and causing them to show up. i don't really know much about astro-photography and i don't know the area, so don't yell at me if there's some really obvious thing in the picture that i'm missing. just wanted to get my thoughts out there.
~Callie

[iomstargazer]

Hi everyone,
I have used Guide 8 software and NORAD data to confirm that the five streaks are from Iridium satellites. The satelites are moving from right to left, starting with the lowest streak and working upwards. The satellites involved are from bottom to top streak:-
IRIDIUM 8 (#24792) 00:40:38h UT (Lowest streak. Slight flare)
IRIDIUM 51 (#25262) 00:49:55h UT (Flare)
IRIDIUM 7 (#24793) 00:56:05h UT (Small duration flare)
IRIDIUM 6 (#24794) 01:06:56h UT (Faint trail)
IRIDIUM 5 (#24795) 01:08:21h UT (Top most very faint trail)

They show on my software as passing exactly as shown in relation to the star background. Times above are when the satellites where in the area of the image.
I positioned my location as 39degree 55minutes North and 32degree 51minutes east, ie Ankara. Date being August 12th.

Regards
Dave

[Chris Peterson]

IRIDIUM 8 (#24792) 00:40:38h UT (Lowest streak. Slight flare)
IRIDIUM 51 (#25262) 00:49:55h UT (Flare)
IRIDIUM 7 (#24793) 00:56:05h UT (Small duration flare)
IRIDIUM 6 (#24794) 01:06:56h UT (Faint trail)
IRIDIUM 5 (#24795) 01:08:21h UT (Top most very faint trail)

Unfortunately, these times are not the times the images were made. From the imager:

The streaks in the picture you see comes from 5 different pictures I took, at 04:23-04:25, 04:31-04:33, 04:41-04:43, 04:51-04:53 ve 04:59-05:01 GMT+3, in the morning of 12th August (not 13th).

Those correspond to
01:23 UT
01:31 UT
01:41 UT
01:51 UT
01:59 UT

There were no Iridium flares in the field at those times. It's possible that the topmost streak is Iridium 90, although it looks like 15821U is a better match. The second streak down is a good match to 21090U. The others match nothing in the satellite catalog.

[iomstargazer]

Had a review of my last post and I find that my initial search is in error as Chris pointed out
My latest re run with Guide 8 comes in agreement with MaG's research:-
IR35 (#24966) 03.23:24 - 03.23:38 (EEST)
IR97 (#24967) 03.32:40 - 03.32:48 "
IR5 (#24795) 03.41:54 - 03.42:06 "
IR6 (#24794) 03.50:52 - 03.51:25 "
IR7 (#24793) 03.59:54 - 04.00:28 "

The above times are from start of streak and end of streak.
There is still a one hour difference between my results and the quoted image times.
I can only beleive that these are iridium streaks as they follow exactly the predicted tracks. We just need to close the issue with the time the photo's where taken.

Regards

Dave

[bystander]

Would Daylight Savings Time account for the extra hour??

[Chris Peterson]

My latest re run with Guide 8 comes in agreement with MaG's research:-
IR35 (#24966) 03.23:24 - 03.23:38 (EEST)
IR97 (#24967) 03.32:40 - 03.32:48 "
IR5 (#24795) 03.41:54 - 03.42:06 "
IR6 (#24794) 03.50:52 - 03.51:25 "
IR7 (#24793) 03.59:54 - 04.00:28 "

I question these results. I don't use Guide, but I've run this through a couple of other propagators, and don't find any of these satellites to be visible from Beynam at the times given (nor an hour later). Here are the topocentric locations of these objects at the specified times on Aug 12:

Iridium 35 24966 00:23:30 28.2247 N 17.2949 W
Iridium 97 27450 00:32:40 28.2829 N 19.3450 W
Iridium 36 24967 00:32:40 32.8082 N 19.1615 W
Iridium 5 24795 00:42:00 28.8329 N 21.6047 W
Iridium 6 24794 00:51:10 29.0469 N 24.0704 W
Iridium 7 24793 01:00:10 28.7113 N 26.3545 W

I list Iridium 36 since that's the correct designation for 24967, not Iridium 97. I note that five satellites are all quite close together, so might produce similar flares. However, their locations are about 5000 km west of Beynam, which is below the horizon and obviously not anywhere near Orion.

BTW, I think the state of twilight in the image strongly suggests that the later times are correct. I doubt the sky would be quite so bright in a two minute exposure at 4am local. At Beynam, the Sun at 4am is 20° below the horizon, which means astronomical twilight hasn't started. At 5am, the Sun is 11° below the horizon, just into nautical twilight.

[FieryIce]

Does your Iridium list include the five satellites just launched this past February by NASA?

NASA's THEMIS Mission Launches to Study Geomagnetic Substorms

These satellites won't be in their final orbits until mid-September and are expected to be a satellite constellation line up along the sun-Earth line.

[gregg07]

There is a light (spotlight?) on the crest of the hill... this is a time exposure... could these not be birds in flight?

[gregg07]

Oops - sorry, someone else also posted this idea. I believe it most likely. There a quite a few streaks - some very dim. These may have been birds not in the brightest part of the beam.

[FieryIce]

Does your Iridium list include the five satellites just launched this past February by NASA?

NASA's THEMIS Mission Launches to Study Geomagnetic Substorms

These satellites won't be in their final orbits until mid-September and are expected to be a satellite constellation line up along the sun-Earth line.

Actually gregg07 if you check Iridium flare fits better.

[Chris Peterson]

Actually gregg07 if you check Iridium flare fits better.

Nope, there were no flares, nor even more than one Iridium satellite in the field at the times the images were made. Also, there's nothing to suggest that the light on the hill is a spotlight aimed at the sky. And it's no less likely to have five birds all flying perfectly parallel at completely different times than it is to have a pair of satellites and three meteors (or three uncataloged satellites). And don't forget that the imager personally witnessed one of these events as a meteor.

[NoelC]

One would think the lines would show up dark against the sky light if there were power lines there.

In my mind the streaks could be bits of a broken up comet fragment traveling together, and briefly illuminating as they burn up in the atmosphere.

-Noel

[Chris Peterson]

One would think the lines would show up dark against the sky light if there were power lines there.

In my mind the streaks could be bits of a broken up comet fragment traveling together, and briefly illuminating as they burn up in the atmosphere.

I think the 36 minute spread from the first to the last is too long for a small object disrupted by tidal forces from its interaction with Earth. The brightness of these meteors (if they are meteors) doesn't suggest more than a few grams of material at most.

An interesting question would be if the 5 streaks are sequential in position with time, or occurred in arbitrary positions over the 36 minute period.

[wawynkoop]

Can someone explain why the periferial stars are streaked away from the center ant the central stars are not streaked?

Also, if Iridium origin, why a similar location and length? the limb of the earth's shadow moves quickly and the location of the illuminated satallite should change over the 40 minutes, no?

[Chris Peterson]

Can someone explain why the periferial stars are streaked away from the center ant the central stars are not streaked?

Most likely this is caused by a combination of poor tracking (or no tracking) and field rotation. You get field rotation when you don't use a mount that rotates with the sky. It looks to me like the area of minimum distortion is the upper left, not the center. The elongated stars might also be partly caused by the stacking process when the five images were combined.

Also, if Iridium origin, why a similar location and length? the limb of the earth's shadow moves quickly and the location of the illuminated satallite should change over the 40 minutes, no?

These definitely were not caused by Iridium satellites, as there was only one in the general area at the time, and not oriented to cause a flare.