Diagonal Streaks only on a certain object

[themongoose85]

I am getting some weird diagonal streaks across the frame only when trying to image Sh2-239. I have never gotten this on other objects I have imaged so far. I have imaged other objects the same night and they don't exhibit this issue. I used the same master darks, bias, and flats so I don't think ti is a calibration issue. I did and always have dithered after every frame and the amount is more than sufficient. The only thing I can think of causing it is that Aldebaran is nearby but out of the frame and is very large and bright. The streaks seem to go in the direction it is in. Has anyone else experienced this before when imaging near other very large bright stars? Any tips on dealing with it? They appear to go from the lower left to upper right.

after a rough full process


nothing but a crop, DBE, and auto STF applied

[themongoose85]

The previous images were stacks of 900sec Lum frames. This one is a stack of 300sec Red frames. It seems to confirm my thinking that the streaks are from Aldebaran as they are not all at a consistent angle and seem to be converging to a single point out of the frame.

[pfile]

in the last image it does seem that the streaks are radiating out from a point as you've noticed. this is pretty typical when there is a bright star just outside of the FOV of the sensor and near the edge of the OTA's field of view.

unfortunately i think the only remedy is to reframe such that aldebaran is further out of the FOV...

rob

[themongoose85]

Thanks. I was afraid that was the only option given the amount of data I already have. Luckily it is still early and I have plenty of time to regather what data i will lose reframing. I worked the new framing up in SGP's Framing and Mosaic wizard. If the forecast holds for Wednesday night I should be able to test it out.

[themongoose85]

Well I tried to reframe as much as I could while still keeping the target on my sensor. The streaks are still appearing. I guess I'll have to wait until I get a longer focal length scope or a larger sensor camera so I can move the scope farther away.