This online article is a supplement to our manuscript on SGL imaging.

We study the images formed by the extended Solar Gravitational Lens (SGL), by placing a telescope in the SGL image plane and moving the telescope.

In the paper, we first (briefly) discuss approach images, which are frames from this animation:


The animation on the left shows the early stages of the approach, the telescope starting at 1,000,000 km from the optical axis, viewing the host star of an exoplanet through the Solar Gravitational Lens.

At this distance, there is little light amplification. The "secondary" image is faint and in reality, would be obscured by the Sun at first; the "primary" image starts off as the unamplified image of the host star, floating into the image area form the right. By the time the telescope is at 4,000 km, light amplification is strong and the two images are symmetrical in appearance.

The middle frame shows the rest of the approach, modeling a telescope that decelerates as it approaches the optical axis. Image brightness is much reduced to accommodate increased light amplification. We can see that the two images of the host star slowly turn into arcs, which eventually merge into an Einstein ring. The Einstein ring reaches maximum brightness when the telescope is on the optical axis, which connects the center of the host star with the center of the Sun.

The image on the right shows the same final approach phase, but with light amplification presented along the third axis, to be more easily quantifiable.

The rest of the paper is about image formation of a point source in the vicinity of the optical axis, as seen by a telescope moving into various positions.

1. SGL animation, optical telescope at 2 m from optical axis


2. SGL animation, optical telescope at 3 m from optical axis


3. SGL animation, optical telescope at 5 m from optical axis


4. SGL animation, optical telescope at 7 m from optical axis


5. SGL color animation, optical telescope at 3 m from optical axis


6. SGL combined animation, optical telescope at 2-7 m from optical axis