Unknon nebula in the Large Magellan Cloud

[Adox (Adriano)]

On the 20th September 2015 I took this photo of the Large Magellan Cloud.

Around the nebula NGC1949 in the Large Magellan Cloud I noted a strange structure not present in any other image found on the web.

What could it be? A post processing mistake or something new?

You can find the high resolution image here: http://myaussiesky.com/galaxies.html

The image is the composition of 45 photos with an exposition of 120s and 28 images for the Tarantula Nebula with an exposition of 30 seconds.

Skywatcher 80ED with 0.75x Riccardi Reducer (F.400 f/5.625).

Modified Canon 6D at 3200ISO

Ayers Rock

[billdan (Bill)]

Hi Adriano,

You are correct when you say it is not shown in other images shown here and elsewhere.

Therefore it must some aberration introduced into the imaging sequence.

Maybe check each of the subs and see if it is present, that will eliminate any calibration or stacking error.

If it was a dirty mark on the optics or camera the same effect will be present on other images. Which means you will have to get some flat fields to eliminate it, assuming you can't see it on the optics and clean it off.

Sorry Adriano, you didn't discover something new.

Regards

Bill

[Adox (Adriano)]

Hi Billdan,

Yes I am sure I did not discover a new nebula. However, I checked all the frames and in any of them is visible this nebula but it appear only during the stacking.

The image is calibrate with flat fields, dark frames and bias.

[Shiraz (Ray)]

maybe have a look at your master flat which may have a dust mote in about this location - one that wasn't there when the lights were taken. Flat fielding will then give you a region with extra gain and that region will move in a path if you have any differential flex in your guiding system. The net effect would be an irregular brighter line feature like this. A spec of some type of fibre on your flat could give the same result.

just a guess.

in any case, it is a nice image.