What is this ?

[Frenchgow]

Hi  I was imaging last night and my target was Ic 348 a small cluster with some nebulosity in Perseus

i started imaging at approx 0030  and had to stop due to cloud 30 minutes later ,I managed to get 3 subs of

600 sec ,the first sub showed this anomaly as did the next 2 subs ,but the object had moved,this is a dark site no street lights

,any ideas what this is?

[Pippy]

Internal reflections ?

[iapa]

It's not a neighbour out with a dog for a walk with a torch?

 

I had something similar - there's a field to N & W where a neighbour takes their dog around 23:00hrs and they wave their torch all over the place

[John]

Iridum flare ?

[steppenwolf]

Your two images are not at the same scale but aligning them in Registar confirms that the horizontal artefacts are at the same vertical distance from the brightest star - they have, however, moved horizontally. Because of the difference in scale (which means one or both are cropped), it is not possible to tell exactly where they appear in a full frame.  Can you post un-cropped images for analysis please?

[Frenchgow]

Hi, not too good at this but here is the first and  last sub I took,reduced quality to get the size down to post,

im sure there's a better way,the bottom image is the first 

[steppenwolf]

Thank you for posting the second set of images. Unfortunately this doesn't help answer the question much other than to confirm that the artefact appears to be related to the bright star as it has changed its vertical position in direct proportion to the change in the position of the star.

So you have a reflection from the bright star that changes in horizontal position inversely to the horizontal position of the star! OK, I'm thinking out loud here but not finding a solution. Can you see anything 'foreign' inside your Newtonian's tube? In particular anything 'shiny' (apart from the mirrors that is!)?

[Frenchgow]

Hi ,thanks for looking ,I had thought of this but no,I took some other subs before these and had no issues

,I image a lot and this is the first time,I've had this happen,a bit of a mystery,

regards Gary

[steppenwolf]

Sorry I can't identify the fault for you! If you do find out what it was, I'd love to know ......

[Davey-T]

Spider web inside the scope ?

Dave

[ollypenrice]

How about an internal reflection from a fixed external source, the movement arising from the tracking?

Olly

[Macavity]

Rather like Dave's spider web theory! Looks slightly diffraction-y?
Google Search "Spider web Diffraction" for some fun images...

Thought there was a trace of colour... but about same as image.
Halo-like? Also seems consistently orthogonal to the star spikes...

A portent re. the NEW LED streetlamp that illuminates anything
that protrudes above the level of my own observatory walls?  

[Frenchgow]

Hi ,having gone through Checking for spider webs loose stuff inside the tube,the thing that baffles me is the fact that the artifact moved while tracking,at the time of imaging the scope was at about 60 deg to the horizon,so pointing above anything reflective around the obshed,I'm now wondering if a scratch on the mirror could have caused this,although while imaging last night there was no indication of this,just one of those things I guess,next move will be to remove and check the mirror

regards Gary

[Jessun]

Could it simply be a reflection caused by the star Atik which seems to be in the rough direction of the glare, and is situated off to the left out of frame?

/Jesper

[Steve Ward]

30 minutes ago, Frenchgow said:

The thing that baffles me is the fact that the artifact moved while tracking.

Ergo the source of the light causing the reflection is not in the field of view but terrestrial fixed and off to one side and bouncing off some reflective surface around the top of the tube ... 

Shiny head of a screw/bolt ... ? , unpainted internal end of the focuser tube protruding into the 'scope  ... ?, unpainted edge of the secondary mirror ... ?

[Frenchgow]

Hi,I think that this is the cause and I'll be checking the tube out tomorrow,relieved that it's probably not the mirror,many thanks 

regards Gary

[steppenwolf]

I really don't think it is the mirror itself so you can rest easy there!

[Ruud]

Using a panorama stitcher, I blended both images after making one red and the other cyan. Then I drew a number of lines on top, all either parallel or perpendicular to each other.

The directions of the phantom streaks very accurately follow the directions of the horizontal diffraction spikes. This probably means something.

What exactly I don't know, but it my first suspects would be the spider vanes and anything parallel or perpendicular to them.

 

[Frenchgow]

Hi,thanks for the effort you put into this ,today I had the scope in the house checking anything that looked like it could be reflective ,I'm out tonight and checking the spider vanes by putting tape over them and taking a shot,and it's definitely a reflexion of the star Atik off one of the flat surface of the spider vane,even though the vanes ,I thought had anti reflective paint,so at least that's solved,a bit of flocking or something similar will cure this,many thanks to you all

regards Gary