Flare Galore! And IGS 1B tumbling?

Flare Galore this evening! Three objects were observed flaring: keyholes USA 186 (05-042A), USA 129 (96-072A), and Lacrosse 4 (00-047A).

The USA 186 flare was spectacular, see the image below. It was a complex double flare. First it very slowly flared to mag. -1.5, peaking round about 20:53:00 UTC. When it was still fading from that flare, a second very short flare was seen at about 20:53:11 UTC. This flare terminated very suddenly, the sat becoming faint in an instance.

Below image shows it all. The peak of the first -1.5 flare coincides more or less with start of the exposure and is at down left (movement is from down left to upper right). The second flare can be seen at upper right. It ended very abruptly with the sat going to naked eye near-invisibility almost at an instance. update (19/04/07): the faint trail extension I thought was real, turns out to be an image artifact.

(click images to enlarge)

Shortly after this, USA 129 flared as well, albeit more modest than USA 186 ten minutes earlier. It reached about mag. +1 at 21:03:30 UTC. The image below shows it fading directly after the flare peak.

(click image to enlarge)

The third flare of this night was produced by Lacrosse 4, and predicted to me by Philip Masding. His prediction was for 21:37:34 UTC: it flared at 21:37:37 UTC. It was a modest flare only. The image is below, the brightness modestly peaks in the second part of the trail.

(click image to enlarge)

This evening I finally successfully observed and captured IGS 1B (03-009B), the Japanese radar satellite that recently reportedly failed. It made a shadow exit at 23:52:50 UTC and was of mag. +2 immediately following that. In the next minute it slowly, irregularly but clearly varied in brightness with an amplitude of about 0.5 to 1 magnitude.

This is quite unlike its steady brighness in past years, so it appears that after the power failure its attitude is now out of control and it is tumbling.

In the image below it is fading, shortly after the end of the exposure it shortly gained brightness again.

(click image to enlarge)

In addition to this all I also watched and photographed a fine pass of the International Space Station around 20:32 UTC, and spotted and photographed a bright stray object near 20:51 UTC while waiting for USA 186: I still have to identify this object as I have not measured that image yet.

Flares of Iridium 14, ISS (!), USA 186 and Lacrosse 4

This evening (the 16th) and the evening of the 14th I observed two nice flares of the same Iridium satellite, Iridium 14 (99-032A). On the 14th it flared to mag. -5, and this evening to -6 (top foto), in twilight. Less than a minute earlier Iridium 70 flared at virtually the same position, but less brightly.

(click images to enlarge)

The International Space Station (ISS) made a number of fine bright passes as well the past days. below are two images of April 14 and 15, including a fine mag. -3.5 twilight pass (top image).

(click images to enlarge)

My new neighbours were on the courtyard enjoying the mid-summer like temperatures (+28 C daytime this weekend, very unusual for mid-April) when I was targetting the twilight pass on the 15th. Seeing me put up my tripod, they asked me what I was doing. I explained, and then pointed out the rising ISS to them. At first they didn't believe me, thinking it was an aircraft, but then they realized I had predicted it to appear, so I probably was right. Still, I could see a look in their face that probably meant something like: "A nutter, but not a dangerous one...".

ISS did something unusual during the 2nd evening pass on the 15th. It was low in the west crossing into Gemini at mag. -2 or so, when suddenly (as if a switch was turned) it flared up by at least 1.5 to 2 extra magnitudes, for maybe a second or 2-3, and then back to its previous brightness again. Very conspicuous. I also had the impression of an orange colour but that could be due to the low elevation. Never seen this before with ISS. Time was approximately 21:07:15 UTC (Apr 15).

Lacrosse 4 (00-047A) flared as well that evening, briefly to mag. +0.5. This was either at 23:09:53 or 23:10:03 UTC (there is some confuson with me about the correct time).

05-042A (USA 186) shortly flared to mag. 0 at 19:45:58 UTC on Apr 15. I catched this flare on photograph but it is so short it is almost stellar. I saw it flare again on the 16th at 20:08:27, to mag. -1 and again very short (maybe a second duration).

Strangely enough I again failed to spot IGS 1B (03-009B), the Japanese radar satellite that recently had a power failure, on the 15th. This although this was a zenith pass, with the sat emerging out of eclipse in the zenith. But I could see no trace of it visually and on the photographs. This while previously this satellite would easily be visible, attaining magnitude +1.5 to +2 during high passes.

Especially the 15th resulted in a nice batch of positions on various objects.

Chasing Keyholes

The past two evenings where very clear again. I spent them chasing Keyholes and Lacrosses.

USA 129 (96-072A) and USA 186 (05-042A) provided some nice flares again. On Saturday the 7th, USA 129 displayed a slow -1 flare at 20:01:00 UTC, and a +2 flare very low in the west during the second pass at 21:38:40. The next evening, its cousin USA 186 flared to mag. 0 at 20:22:30 UTC in pretty much the same local sky area as USA 129 did the previous evening. In both cases they peaked in brightness before my first exposure started, and I catched them fading again (see image below).

I also obtained my first point on the Japanese radar sat IGS 1B (03-009B) since its reported failure. It came out of eclipse just above the rooftops, the trail on the image is still faint and hence I am not too confident in the single position I obtained.

In the next few weeks, moving away from spring equinox, the IGS-es will come higher and higher in the sky. There is a new set of recently launched IGS objects I hope to start tracking besides IGS 1B.

As usual the Lacrosses were covered again too. Lacrosse 5 (05-016A) did its "disappearance trick" again on the 7th at 19:30:17 UTC. The other Lacrosse target was Lacrosse 2 (91-017A).

For yesterday evening, I had USA 129 less than 0.1 s "late", but clearly off-track by 0.08 degree. USA 186 was as much as 0.9s late but on-track. Lacrosse 2 was less than 0.1s "early" and on-track.

The image below shows USA 129 (96-072A) some 15 seconds after a flare peak, still being mag. +2, crossing near the Coma cluster on the 7th.

(click image to enlarge)

Flaring USA 193 and USA 186

The past 3 nights were very clear and transparent, and with the moon gone, this meant good opportunities for observations in the evening.

Yesterday evening I was treated to some nice flares, and observed USA 193 (06-057A) being very bright for the second time.

The bright appearance of USA 193 was again on a west-southwest pass, just like two days ago. In other parts of the local sky, it remains too faint to observe for me. But like my observation of two days ago, it now again reached magnitude +1.5, easily visible to the naked eye (and camera eye).

The bonus was in a sudden bright flare it produced at 19:37:50 UTC. It was a short but bright flare (about 1 second duration) reaching magnitude -1.5 and with a conspicuous yellow-orange colour. This alas happened some 10 seconds after the end of my exposure.

Now I do know it is so bright when appearing in this part of the sky, I'll start to monitor these south-western passes of USA 193 (earlier I had given up after trying to observe several passes in the northern sky in vain).

Keyhole USA 186 (05-016A) was another target of last evening, and it produced two flares, a slow one to mag. -2 at 20:53:40 UTC and a fast one to mag. 0 at 20:54:10 UTC. Again, not while the camera was opene: I did catch the last fading part of the first flare though, the sat still being mag. +2.5 when my camera opened some 5 seconds after the peak of the first flare.

I had USA 193 some 0.6 to 0.7 seconds late and on-track with regard to Ted's latest elset 07094.84492728, and USA 186 some 3.1 to 3.3 seconds early with regard to Mike's elset 07090.85107920 and notably off-track by 0.05 to 0.08 degree.

During the two nights previous to this I obtained a rich haul of positions on USA 129 (96-072A), USA 193 (06-057A), and Lacrosse 2 & 5 (91-017A & 05-016A). Especially the evening of the 3rd was a bounty, with 15 positions gathered.

Below images from last evening show USA 193 traversing Gemini at mag. +1.5, and USA 186 fading from it's first flare.

(click images to enlarge)

More KH flare fun

Observing a flare as a bonus to position determinations keeps being the icing on the cake for me. Last night Keyhole USA 186 (05-042A), the real one this time ;-) , did it again. I flared to magnitude -1 in the zenith at 21:01:10 UTC.

My camera opened about 10 seconds later, when the satellite was already well past the flare maximum. It is still of about mag. +2 at the start of the trail on the image, but fades to invisibility during the exposure.

Other targets imaged last night were the SAR satellites Lacrosse 5 (during two passes) and Lacrosse 2.

Lacrosse 2 (91-017A) was 2.3s early. Lacrosse 5 (05-016A) 0.4s late. USA 186 was on-time.

I am eagerly awaiting the opening of the springtime visibility window of the Japanese radar satellite IGS 1B (03-009B). After several years of operation this satellite recently reportedly failed in orbit. While operational its orbit was tightly controlled by almost daily small orbit manoeuvres keeping it very steady. It is interesting to see whether that level of control is now dropped (early results by other trackers indeed suggest such).

Another case of identity confusement

It must be in the air or something, but yesterday evening I again mixed up two satellites, and again it involved USA 186.

This time, I observed a magnitude zero flare in the zenith at 20:35:10 UTC and mistakenly reported it to the Seesat list as being a flare of USA 186 (05-042A).

In reality, it was another Keyhole, USA 129 (96-072A). USA 186 would pass 10 minutes later along a similar track...

It shows up on two images (both taken after the flare) and yielded 4 positions, the last of which is probably in error.

I also covered two passes of Lacrosse 5 (05-016A). The first pass was a twilight pass and Lacrosse 5 remained "hidden" most of that pass, except for a brief period of maybe 30 seconds after 19:14:10 UTC, when it suddenly appeared just east of Polaris at about mag. +2.5. Lutz reported it was gone again by 19:14:47 UTC.

The second pass saw no disappearance event. Lacrosse 5 was bright and steady, and four photographs yielded 8 positions.

With regard to the night previous to this, I can add a few things. First the confusion between Keyhole USA 186 and the weathersatellite NOAA 14 when the latter was producing a brilliant flare. As can be seen from the following diagram, the two were indeed cruising up very closely at that time, hence why they were so easily confused. At the time of the bright flare which I captured on photograph, they were only 8 degrees apart in azimuth and 0.2 degrees in elevation.

(click diagram to enlarge)

In addition, I can also report that I obtained positions on USA 129 and Lacrosse 5 that night.

Of brilliant flares, and confusion... (UPDATED & CORRECTED)

UPDATED & CORRECTED

In the original version of this post, I wrote:

A quick post about the two nice flares by Keyhole USA 186 (05-042A)I just observed. The first occurred in the zenith at 20:23:25 UTC just after the end of my first exposure. It reached mag. 0. A second bright slow flare reaching magnitude -1 happened at 20:24:15 UTC and this time the camera was open. The very fine result can be seen below.

Well, forget that. And shamefaced here. When measuring the images, the delta T came out several seconds errative, and the cross-track error in position some 3-4 degrees.....and I don't make such mistakes, so the only option was that it must be another object...

Hence it was not USA 186 flaring. In fact, an ID run with IDSat and a full satellite catalogue identified the flaring object as NOAA 14 (94-089A, #23455), a weather satellite.

They were cruising up together only a few degrees apart, hence the misidentification. USA 186 is known to produce flares, so when I saw a satellite flaring up near the USA 186 position I assumed it was USA 186....in error.

More results on this night will be posted later in a second post.

(click image to enlarge)