What is this phenomenon in my token pictutres?!!

Mon, 09/07/2015 - 08:06

Hello.
I am a senior student and my major is gravity. I also interested in astrophysics. about 3 weeks ago I could record transiting of exoplanet HD189733 b for the first time in my country, Iran:
http://var2.astro.cz/EN/tresca/transit-detail.php?id=1440860355
I am so happy for that! but the thing that I want to share with you is something that is recorded in 4 pics of this observation. something like a gamma jet from a neutron star or like that! I really do not know what is it, noise or something relevant to the atmosphere or...?!  I just want to hear from you that what could it be.

this is the 4 pictures in time order (from top to bottom)
http://s3.picofile.com/file/8210729592/1234.jpg

The telescope was: MEADE LX200 16 inch
The CCD: SBIG 11000CM
Exposure time: 2.5 sec
Filter: clear
Bining: 1*1 (so the time between each pictures was about 1 min)

Thanks whom that share their opinions with me!