<p>It's shutter vibration. It begins at one end of the trail (which I'm guessing is the start of the exposure) and quickly damps out. </p>

<p><a href="https://i.sstatic.net/zqo4v.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/zqo4v.png" alt="enter image description here"></a></p>

CC BY-SA 4.0
2019-12-28T07:21:02.220Z
I thought it might have been a spiralling object coming toward me. It is also likely that the electronic shutter was open and still as it was exposed for 25 seconds. It's not a typical DSLR shutter
Michael Beamish
CC BY-SA 4.0
2019-12-28T09:03:33.937Z
@MichaelBeamish how did you trigger the shutter? Did you have to touch the camera or use a remote control (e.g. IR or Bluetoosh)?
uhoh
CC BY-SA 4.0
2019-12-28T09:23:46.903Z
It was on a 2 second delay, which is more than enough time to stabilise. The shaking would have to occur while the 'shooting star' was in motion to have affected it which is only a short amount of time isn't it? Like a split second? Also the stars are not blurry as it would have impacted them also right?
Michael Beamish
CC BY-SA 4.0
2019-12-28T10:22:08.967Z
@MichaelBeamish The vibration is  a very small part of the exposure time (around 1%, if you measure the relative length on the trail) so the blur on the stars would be very hard to notice.
xenoid
CC BY-SA 4.0
2019-12-28T11:05:41.533Z
The shooting star occurred while the shutter was open, which was for about 25 seconds. The shutter closed well after the event. The more I think about it, the less I believe it was vibration from the shutter. It could have occurred from something else, but long exposures mean that nothing is moving for a long time. What else could it be?
Michael Beamish
CC BY-SA 4.0
2019-12-28T13:40:20.370Z
@MichaelBeamish I see what you mean. Are you 100% sure is a meteor and not a satellite? Since they [can move fairly slowly sometimes](https://space.stackexchange.com/a/27101/12102) (1.4 down to 0.2 degrees/sec) if you just glance at intervals a satellite will look just like a non-distinct random star, we only know they are satellites when we watch for a while and notice them slowly creep against the other stars. I still think it's shutter vibration, but the trail is caused by an artificial satellite.
uhoh
CC BY-SA 4.0
2019-12-28T13:42:04.630Z
@MichaelBeamish There are many sites that will predict satellite trails for you. You can type in the approximate time and the date and your lat/lon cooridnates and websites will tell you the satellites that were passing then, even make a map for you.
uhoh
CC BY-SA 4.0
2019-12-28T13:55:19.670Z
@MichaelBeamish (there could have been a shooting star also, but this could still be a satellite in your image) There are many sites that will predict satellite trails for you. You can type in the approximate time and the date and your lat/lon cooridnates and websites will tell you the satellites that were passing then, even make a map for you. I'm still betting this is a satellite and that's shutter vibration.
uhoh
CC BY-SA 4.0
2019-12-28T18:24:18.290Z
From the shot duration and the length of the star trails, I have the math right the first arc would be a 120m wobble for an object in low orbit (100km). That would require some serious acceleration. Also in the shot was taken in the middle of the night, it can't be a satellite (there are in earth shadow). So if the wobble is an object move, it is much closer (plane).
xenoid
CC BY-SA 4.0
2019-12-28T18:32:16.537Z
More math: at 100km, given the length of the trail, the object moves at 1.4km/s, so it is not in orbit (8km/s minimum), to be in orbit it should be 6 times farther, but then the initial wobble is about a kilometer.
xenoid
CC BY-SA 4.0
2019-12-29T02:14:07.650Z
@xenoid I don't see any math yet, but if you have some that applies here then it would be *really great* if you posted it as an answer! The altitude determines how late or early a satellite can be seen. What you are saying is roughly correct for the ISS or other low objects circa 400 km, but an object can be much higher also and therefore be seen much later or earlier. Also assuming 400 to 1000 km altitude the associated velocity would be closer to 7.4 to 7.8 km/s LEO orbital velocity (1000 to 400 km).
uhoh
CC BY-SA 4.0
2019-12-29T02:18:47.813Z
@xenoid Without the elevation above horizon, we can't [convert](https://space.stackexchange.com/a/27101/12102) angular speed to orbital speed. Basically there needs to be more data (lat/lon, time, direction) before we can conclude anything with 100% about the visibility of a satellite in the photo.
uhoh
CC BY-SA 4.0
2019-12-29T03:03:07.007Z
@uhoh I'll get that shortly. Great discussion here, cheers.
Michael Beamish
CC BY-SA 4.0
2019-12-29T03:24:24.920Z
@uhoh the elevation of Warragul our town in Australia is 143m. I was facing approximately 58-60 degrees NE. The time was 920.19pm, on the 26th December. Warragul is 38.1538 S, 145.9298 E. I was on a manfrotto tripod was about 5-6' off the ground and angled approximately 50-60 degrees. Is this enough info?
Michael Beamish
CC BY-SA 4.0
2019-12-29T03:32:29.653Z
@MichaelBeamish That's great, thank you! Do you mean 21:20:19 local time, (which is UTC +11)? I think that's all that is necessary. From the star pattern I think we can reconstruct the exact direction using Astronomy.net ([How (the heck) does Astrometry.net work?](https://astronomy.stackexchange.com/q/33575/7982))
uhoh
CC BY-SA 4.0
2019-12-29T04:22:16.037Z
@uhoh yes 21:20:19 local. Sorry I didn't think to convert it
Michael Beamish
CC BY-SA 4.0
2019-12-30T22:43:02.117Z
Rather than shutter vibration, it might be an artifact of built-in image stabilization algorithms.  I agree it appears to "damp out" but I don't see any intensity variation in the star images (which, moving much more slowly relative to the camera, if damping out would be brighter at the tail-end of the exposure).
Carl Witthoft
CC BY-SA 4.0
2020-01-02T22:36:50.337Z
@CarlWitthoft below is a photo (basketball hoop) on the same night only a few minutes apart. The streak of the object is mostly clean. In this case you can see one end is much dimmer than the remainder. Is that what you mean?

https://imgur.com/fStkccE
https://imgur.com/gsqAUBG
Michael Beamish
CC BY-SA 4.0
2020-01-10T12:09:10.403Z
@uhoh I had a closer look today and if you look at the image hosted at Imgur https://imgur.com/fStkccE you can see that the line is not straight along it's entirety whereby if you look at the shooting star in the other link https://imgur.com/gsqAUBG you can see it quite straight. Taken 2 minutes apart with approximately the same settings. I'm certain that the object has some sort of oscillation along its entire path that must accelerate or become more pronounced if it is coming toward us, but if it is headed away from us then the oscillation continues as it streaks away. What do you think?
Michael Beamish
CC BY-SA 4.0
2020-01-10T13:39:29.760Z
@MichaelBeamish Oh I lost track of this, okay I'll have a closer look this weekend. Thanks!
uhoh
CC BY-SA 4.0
2019-12-28T02:00:27.860Z
2019-12-28T02:00:27.860Z
uhoh
<p>I was taking photos of some stars when I noticed this shooting star was wavy toward the end (start?) of it's trail. My cousin suggesting that it could be the CCD in my camera or as it spiralling as it enters the atmosphere. This is a heavily cropped image </p>

<p><img src="https://i.sstatic.net/sWqOg.jpg" alt="Shooting star"></p>

<p><img src="https://i.sstatic.net/MRyqN.jpg" alt="full picture"></p>

CC BY-SA 4.0
2019-12-27T21:13:57.097Z
Wobbling or spiralling seems much more likely than CCD issues in this image.
Rory Alsop
CC BY-SA 4.0
2019-12-27T23:36:24.977Z
Do you think it is entering atmosphere?
Michael Beamish
CC BY-SA 4.0
2019-12-28T08:04:48.310Z
Of course it had already entered the atmosphere @Michael Beamish else how could we it?
Alchimista
CC BY-SA 4.0
2019-12-30T22:44:59.877Z
The stars have traces, suggesting your camera was not tracking. True?  Does your camera have an internal "image stabilization" algorithm running?  For that matter, we might need to dig into the readout order & FET switching to determine if there are pixel-drain artifacts ("bleeding" into neighbors)
Carl Witthoft
CC BY-SA 4.0
2020-01-04T13:50:35.240Z
@MichaelBeamish What type of camera where you using? Please be specific (i.e. not "mirrorless" but instead "Pentax K1 Mark II.")
Michael C
CC BY-SA 4.0
2020-01-04T13:51:04.863Z
The stars have jitters as well, they're just not as obvious.
Michael C
CC BY-SA 4.0
2020-01-04T13:52:43.037Z
@Michael C I'm using the Sony Mirrorless A7Rii with a SEL1635GM lens
Michael Beamish
CC BY-SA 4.0
2020-01-04T13:54:09.320Z
@Carl Witthoft I don't have tracking and I disable image stabilisation. Can you elaborate what FET switching is?
Michael Beamish
CC BY-SA 4.0
2020-01-04T13:59:01.723Z
@MichaelBeamish That camera has a fully mechanical shutter as well as the option to use electronic first curtain. Which option does the EXIF info indicate was selected for this photograph?
Michael C
CC BY-SA 4.0
2020-01-04T14:01:40.017Z
@Michael C Ill check BRB
Michael Beamish
CC BY-SA 4.0
2020-01-04T14:21:03.477Z
@Michael C I checked and I can't see in the exif data whether it was one or the other. I do know however that I have not got that setting enabled in the camera.
Michael Beamish
CC BY-SA 4.0
2020-01-04T14:21:15.030Z
Let us [continue this discussion in chat](https://chat.stackexchange.com/rooms/102876/discussion-between-michael-beamish-and-michael-c).
Michael Beamish
<amateur-observing><meteor><identify-this-object>
Why is this shooting star wavy or squiggly toward the end of it's visible streak
Michael Beamish
# Why is this shooting star wavy or squiggly toward the end of it's visible streak

(Asked by: username_0 on 2019-12-27)

I was taking photos of some stars when I noticed this shooting star was wavy toward the end (start?) of it's trail. My cousin suggesting that it could be the CCD in my camera or as it spiralling as it enters the atmosphere. This is a heavily cropped image

![Shooting star](https://i.sstatic.net/sWqOg.jpg)

![full picture](https://i.sstatic.net/MRyqN.jpg)

**Tags:** amateur-observing, meteor, identify-this-object
> **Comments:**
> **username_1**: Wobbling or spiralling seems much more likely than CCD issues in this image.  
> **username_0**: Do you think it is entering atmosphere?  
> **username_2**: Of course it had already entered the atmosphere @Michael Beamish else how could we it?  
> **username_3**: The stars have traces, suggesting your camera was not tracking. True?  Does your camera have an internal "image stabilization" algorithm running?  For that matter, we might need to dig into the readout order & FET switching to determine if there are pixel-drain artifacts ("bleeding" into neighbors)  
> **username_4**: @MichaelBeamish What type of camera where you using? Please be specific (i.e. not "mirrorless" but instead "Pentax K1 Mark II.")  
> **username_4**: The stars have jitters as well, they're just not as obvious.  
> **username_0**: @Michael C I'm using the Sony Mirrorless A7Rii with a SEL1635GM lens  
> **username_0**: @Carl Witthoft I don't have tracking and I disable image stabilisation. Can you elaborate what FET switching is?  
> **username_4**: @MichaelBeamish That camera has a fully mechanical shutter as well as the option to use electronic first curtain. Which option does the EXIF info indicate was selected for this photograph?  
> **username_0**: @Michael C Ill check BRB  
> **username_0**: @Michael C I checked and I can't see in the exif data whether it was one or the other. I do know however that I have not got that setting enabled in the camera.  
> **username_0**: Let us [continue this discussion in chat](https://chat.stackexchange.com/rooms/102876/discussion-between-michael-beamish-and-michael-c).  

---

## 1 answers

### Answer by username_5 on 2019-12-28. Score: 3

It's shutter vibration. It begins at one end of the trail (which I'm guessing is the start of the exposure) and quickly damps out.

[![enter image description here](https://i.sstatic.net/zqo4v.png)](https://i.sstatic.net/zqo4v.png)

> **Comments:**
> **username_0**: I thought it might have been a spiralling object coming toward me. It is also likely that the electronic shutter was open and still as it was exposed for 25 seconds. It's not a typical DSLR shutter  
> **username_5**: @MichaelBeamish how did you trigger the shutter? Did you have to touch the camera or use a remote control (e.g. IR or Bluetoosh)?  
> **username_0**: It was on a 2 second delay, which is more than enough time to stabilise. The shaking would have to occur while the 'shooting star' was in motion to have affected it which is only a short amount of time isn't it? Like a split second? Also the stars are not blurry as it would have impacted them also right?  
> **username_6**: @MichaelBeamish The vibration is  a very small part of the exposure time (around 1%, if you measure the relative length on the trail) so the blur on the stars would be very hard to notice.  
> **username_0**: The shooting star occurred while the shutter was open, which was for about 25 seconds. The shutter closed well after the event. The more I think about it, the less I believe it was vibration from the shutter. It could have occurred from something else, but long exposures mean that nothing is moving for a long time. What else could it be?  
> **username_5**: @MichaelBeamish I see what you mean. Are you 100% sure is a meteor and not a satellite? Since they [can move fairly slowly sometimes](https://space.stackexchange.com/a/27101/12102) (1.4 down to 0.2 degrees/sec) if you just glance at intervals a satellite will look just like a non-distinct random star, we only know they are satellites when we watch for a while and notice them slowly creep against the other stars. I still think it's shutter vibration, but the trail is caused by an artificial satellite.  
> **username_5**: @MichaelBeamish There are many sites that will predict satellite trails for you. You can type in the approximate time and the date and your lat/lon cooridnates and websites will tell you the satellites that were passing then, even make a map for you.  
> **username_5**: @MichaelBeamish (there could have been a shooting star also, but this could still be a satellite in your image) There are many sites that will predict satellite trails for you. You can type in the approximate time and the date and your lat/lon cooridnates and websites will tell you the satellites that were passing then, even make a map for you. I'm still betting this is a satellite and that's shutter vibration.  
> **username_6**: From the shot duration and the length of the star trails, I have the math right the first arc would be a 120m wobble for an object in low orbit (100km). That would require some serious acceleration. Also in the shot was taken in the middle of the night, it can't be a satellite (there are in earth shadow). So if the wobble is an object move, it is much closer (plane).  
> **username_6**: More math: at 100km, given the length of the trail, the object moves at 1.4km/s, so it is not in orbit (8km/s minimum), to be in orbit it should be 6 times farther, but then the initial wobble is about a kilometer.  
> **username_5**: @xenoid I don't see any math yet, but if you have some that applies here then it would be *really great* if you posted it as an answer! The altitude determines how late or early a satellite can be seen. What you are saying is roughly correct for the ISS or other low objects circa 400 km, but an object can be much higher also and therefore be seen much later or earlier. Also assuming 400 to 1000 km altitude the associated velocity would be closer to 7.4 to 7.8 km/s LEO orbital velocity (1000 to 400 km).  
> **username_5**: @xenoid Without the elevation above horizon, we can't [convert](https://space.stackexchange.com/a/27101/12102) angular speed to orbital speed. Basically there needs to be more data (lat/lon, time, direction) before we can conclude anything with 100% about the visibility of a satellite in the photo.  
> **username_0**: @uhoh I'll get that shortly. Great discussion here, cheers.  
> **username_0**: @uhoh the elevation of Warragul our town in Australia is 143m. I was facing approximately 58-60 degrees NE. The time was 920.19pm, on the 26th December. Warragul is 38.1538 S, 145.9298 E. I was on a manfrotto tripod was about 5-6' off the ground and angled approximately 50-60 degrees. Is this enough info?  
> **username_5**: @MichaelBeamish That's great, thank you! Do you mean 21:20:19 local time, (which is UTC +11)? I think that's all that is necessary. From the star pattern I think we can reconstruct the exact direction using Astronomy.net ([How (the heck) does Astrometry.net work?](https://astronomy.stackexchange.com/q/33575/7982))  
> **username_0**: @uhoh yes 21:20:19 local. Sorry I didn't think to convert it  
> **username_3**: Rather than shutter vibration, it might be an artifact of built-in image stabilization algorithms.  I agree it appears to "damp out" but I don't see any intensity variation in the star images (which, moving much more slowly relative to the camera, if damping out would be brighter at the tail-end of the exposure).  
> **username_0**: @CarlWitthoft below is a photo (basketball hoop) on the same night only a few minutes apart. The streak of the object is mostly clean. In this case you can see one end is much dimmer than the remainder. Is that what you mean?  https://imgur.com/fStkccE https://imgur.com/gsqAUBG  
> **username_0**: @uhoh I had a closer look today and if you look at the image hosted at Imgur https://imgur.com/fStkccE you can see that the line is not straight along it's entirety whereby if you look at the shooting star in the other link https://imgur.com/gsqAUBG you can see it quite straight. Taken 2 minutes apart with approximately the same settings. I'm certain that the object has some sort of oscillation along its entire path that must accelerate or become more pronounced if it is coming toward us, but if it is headed away from us then the oscillation continues as it streaks away. What do you think?  
> **username_5**: @MichaelBeamish Oh I lost track of this, okay I'll have a closer look this weekend. Thanks!  

---

