Mystery satellite "UNKNOWN 101208" is PAN!

Those of you following this observing blog and the Satobs list, will be aware of the observations of the past week of what appeared to be an unknown geostationary satellite.

It was first observed on December 8th by me, and next by Greg Roberts as well (see here for the discovery, as well as here, and here for the follow-up).

It was first thought to be perhaps DSCS 3-11, but that turned out to be incorrect. So it was a bit of a mystery, as no recent launch was a candidate either. And geosats just don't "materialize" in the sky. Obviously, this was an older geosat being relocated: but which one?!

The mystery has now been solved, by Greg Roberts. The satellite is PAN (2009-047A), relocating to a position more to the east.

Greg imaged the old position of PAN (close to Paksat 1) on the 12th, but couldn't detect it. So he made the obvious conclusion: PAN was gone and identical to the eastwards drifting satellite we called "Unknown 101208" since December 8th.

I can actually confirm Greg's result of the 12th: I imaged the "old" position as well that same evening and like Greg find no trace of PAN, only Paksat 1 is present.

So how about my "observation" of PAN near the "old" position on December 8th, the same evening that I first spotted "Unknown 101208"?!?

It is very embarasing, but I turn out te have been fooled by an image artefact! With hindsight, I should have been suspicious: the little dot I thought was PAN was quite faint, and visible on only one out of 2 images. This unlike my November 28th observations, when the true PAN clearly showed up in its "old" position on multiple images.

Below image shows the image artefact that fooled me on the 8th (the insets show details of this image, and a second image taken 20 seconds later on the same evening which only shows Paksat 1 - which with hindsight should have warned me).

click image to enlarge

Here is another image, showing PAN and Paksat 1 on November 28, and Paksat 1 with PAN no longer present on December 12th.

click image to enlarge

With the current drift rate of just under 0.5 deg/day, PAN probably started to relocate on or around December 1st.

Recovering SDS 3-3 (USA 179) and following the UNKNOWN 101208 geosat

Our amateur network had lost track recently of the HEO satellite SDS 3-3 (USA 179, 2004-034A), so it had to be recovered. Radio doppler shift data by an amateur remaining anonymous provided enough information to Ted Molczan to issue a search orbit for visual or camera recovery.

Last evening started clear, and I quickly recovered it very close to Ted's predicted search orbit position. It was about 0.3 degrees off from the latter, so a very neat result! See the image below, the first in a series I shot yesterday with the Carl Zeiss Jena Sonnar MC 2.8/180mm:

click image to enlarge

After imaging another HEO too, the ELINT USA 184 (2006-027A), clouds came in. The situation turned very dynamic, with the sky going from clear to clouded to clear in a matter of minutes.

I wanted to see if I could image the 'mystery geostationary satellite' which I discovered on 8 December again, a satellite that has now been temporarily designated as Unknown 101208. With my initial December 8 observations and Greg Robert's December 9 & 10 observations, Mike could fit a reasonably good orbit:

Unknown 101208
1 99991U          10344.69054052 0.00000000  00000-0  00000-0 0    03
2 99991   0.0670  10.3484 0003000 147.2004 212.7996  1.00405600    05

The object is drifting eastward at a rate of about 0.5 degrees/day and is now well east of the Turksat 2A & 3A duo (it was west of them when I discovered it on the 8th). It's identity still remains a mystery. Early ideas about it being a DSCS relocating, can now be dismissed.

Under very dynamic conditions, I managed to take advantage of a clearing that lasted literally only minutes (!) to capture it again last evening, along with a few others in the same image. The latter objects were the Milstar 6 r/b (2003-012B) and Mentor 4 (USA 202, 2009-001A), and in addition the non-classified geostationaries Turksat 2A & 3A, Thuraya 2 and Express AM-1.

While the image quality was bad (quite fogged images), the object clearly showed up. Below is one of the images, showing the mystery satellite with the Turksat duo. Compare to the December 8th picture here, when the mystery satellite was still west of the Turksats:

click image to enlarge