The images from STEREO's COR1 and COR2 White Light cameras
suffer from lens
The ones that we are seeing your images are explained here:
There are also some permanent artifacts in the instrumental backgrounds of the COR1 telescopes. Since these artifacts are always there, in a
perfect world they would be removed in the background subtraction process. However, they are sensitive to small moment-by-moment changes in the
spacecraft pointing, and thus cannot be completely removed. The artifacts are demonstrated in the images below. (Only a few representative artifacts
have been circled.) They are caused by small defects in the field lens of each COR1 telescope, though some have also appeared since launch due to the
migration of individual dust particles onto the surface of the field lens. Although they can appear anywhere within the image, they are most visible
near the edge of the occulter. These artifacts appear as bright rings with a dark center, reflecting the shape of the input aperture with the occulter
in the center. Generally, only one side or edge of the ring is visible, giving the artifact a "fingernail" appearance.
source for text and above images
The white circle in the above images is were the physical location of the sun and it's actual diameter is in each image.
As you can see, it does not extend past the Coronagraph
blocking the sun light).
Satellite based Coronagraphs can suffer from issues along with the camera equipment and lenses:
While space-based coronagraphs such as LASCO avoid the sky brightness problem, they face design challenges in stray light management under the
stringent size and weight requirements of space flight. Any sharp edge (such as the edge of an occulting disk or optical aperture) causes Fresnel
diffraction of incoming light around the edge, which means that the smaller instruments that one would want on a satellite unavoidably leak more light
than larger ones would. The LASCO C-3 coronagraph uses both an external occulter (which casts shadow on the instrument) and an internal occulter
(which blocks stray light that is Fresnel-diffracted around the external occulter) to reduce this "leakage", and a complicated system of baffles to
eliminate stray light scattering off the internal surfaces of the instrument itself.
In your gifs where you have the image rotating, you can see that the strands of the sun's actual corona are rotating too, indication motion in the
STEREO satellite, where as the lens artifacts (the "cloudy" area around the coronagraph and your "object" do not seem to rotate, indicating that
they are actually in the camera system and not external to it).
Another thing we can do is:
Look at other images of the sun at the same times or near same times that your "objects" are being shown:
Here is your image with your "objects" in it. The image was taken by STEREO B COR1 White Light on 17 June 2013 at 16:45
Here is a image from STEREO A COR1 White Light same date as above, but only 5 minutes later:
We see the "cloudy" lens artifacts......but your "object" is not there.
Let's look at other solar observatories taking pictures at that time too:
Here is a image from SOHO using the LASCO C2 White Light detector, only 9 minutes before your image:
No objects in sight.......
Again from SOHO, LASCO C3 White Light taken only 3 minutes before your image:
Stars....planet......corona whisps.....but I again am not seeing your "objects"........
That's because they don't actually exist, and are camera and lens artifacts.
While I understand that it can be easy to get excited over things that do not look right to you, in the future, you might want to research more about
the equipment that actually takes these images, their flaws, defects and artifacts that can appear in the images.
Also, as I showed, never depend on just one camera. If something is really there, it helps to have independent confirmation from a different
camera.....that way you can actually prove that something is there, as it's showing up in other images and can not be written off as a camera or lens