Sunday 29 April 2007

USA 116 flaring

Pierre recovered USA 116 (95-066A) on the 24th. I observed it this morning, making a nice pass high west.

It was bright for much of its track, +2 to +1, and slowly flared to +0.5 at 02:05:45 UTC (29 April) on the Bootes-Corona Borealis border. An image of this flare is below.

Five minutes earlier I observed a nice flare of Iridium 61 (predicted -8 but I think it was a bit fainter), see also below (2nd image).

(click images to enlarge)

Thursday 26 April 2007

Another METOP-A flare, hazy skies and timings again

The skies have turned hazy since yesterday. With the moon and the urban environment, this means serious tracking is very difficult.

I observed another flare of METOP-A (06-044A) yesterday (25 Apr) at 20:08:42 UTC. I watched this pass because the track and time were very close to that of the flare observation of the 20th.

Indeed, it flared at virtually the same spot, in the tail of the Big Dipper. Due to the conditions the brightness was difficult to estimate: certainly mag. 0, possibly -1. With the naked eye I could barely make out the dipper stars itself, but the flare was easily visible.

There are still some strange things going on with my timings. I have chosen to target as many non-classifieds as possible to get some insight into the timing consistency.

Sunday 22 April 2007

4 flares in 15 minutes

This morning and evening of the 22nd, I managed to catch a number of fine flares again, four of which occurred within a time span of 15 minutes:

- two Iridium flares (-2 and -5, by Iridium 61 and 03 resp.);
- two USA 186 flares (-0.5 and 0), 20:44:33 and 20:45:26 UTC;
- a Lacrosse 4 flare (+1, predicted by Phil Masding), 20:41:54 UTC.

Images are below. The evening ended early when cirrus came in.

The Lacrosse flare was predicted by Philip Masding (just like the Lacrosse flare of yesterday) to within 2 seconds of time exactly.

Flares never bore me, they are always exciting to watch, and even more so when they occur at random and are so nice to do so while the camera is open....

(click images to enlarge)

A timing re-calibration and another flare bonanza

Following the discovery of time discrepancies having crept into my results, I have added a -0.35 second correction as of last evening's results. The results now come much more in-line again.

In order to test this I targeted a number of objects last night, including some Iridium passes. Apart from two Iridium flares, I managed to catch some flares of classifieds again.

Here is Keyhole USA 186 (05-042A) flaring to mag. 0 in the east at 20:21:25 UTC:

(click image to enlarge)

Philip Masding notified me ahead of a possible Lacrosse 4 (00-047A) flare at 21:46:15 UTC: I observed it flaring to mag. +0.5 at 21:46:17 UTC:

(click image to enlarge)

USA 129 (96-072A) flared to -1 at 20:34:30 UT in the sickle of Leo, alas inbetween two images, and in general was bright in the first half of its pass:

(click images to enlarge)

ISS made a nice pass close to Procyon in deep twilight. The wisps of cirrus still present at that time would rapidly dissolve:

(click image to enlarge)

Saturday 21 April 2007

Timing errors and a mag. -5 IGS 1B flare

After the unexpected METOP-A flare of yesterday evening, I was surprised by another unexpected flare. And what a flare: it concerned the failed Japanese radar satellite IGS 1B (03-009B) flaring at about 21:06:20 UTC to magnitude -5!

It happened after I had taken a photograph of IGS 1B and was in the process of moving my tripod to another corner of the courtyard. I suddenly saw it flaring so brilliantly with a distinct yellowish colour and my jaw dropped. I didn't get the chance to aim and get a shot of it.

I have never seen IGS 1B do this before. Together with the somewhat irregular brightness behaviour in past evening sightings, I think it underlines that it is tumbling out of control.

On a less positive note, I seem to have developed a time lag in my positions lately. They seem to be about 0.35 seconds too late in general. All positions produced from now on will incorporate a 0.35s correction therefore and we'll see whether things get in line again.

The most likely source of the timing error is in the camera (another much less likely option is in the DCF77 signal). Indeed I recently did access my camera with other software than usual, which seems to have done something to my settings.

The timing accuracy keeps being a head-ache and the bottle-neck of the technique I employ, together with the effects of random noise (and the noise suppression routine) in the image.

Yet for now my current equipment is all I can afford, so I'll just have to do with it.

Below is another image of yesterday, showing Keyhole USA 129 (96-072A) crossing at mag. +1 close to the coma cluster (here shown at reduced resolution, so some of the fainter stars are lost).

(click image to enlarge)

Friday 20 April 2007

Bonus flare of unknown (=Metop-A) with USA 129 (UPDATED)

"Something" just produced a fine mag. -1.5 flare only a few degrees from USA 129. I have not identified the flaring object yet. I could see the two cruise up with each other on roughly parallel tracks, a few degrees apart, USA 129 at +2.5, in Ursa Major. The flarer was leading and produced the flare at 20:12:10 UTC. See image below. The fainter trail is USA 129.

USA 129 itself (I believe) produced a flare of mag. 0 low in the east at about 20:11:00 and remained bright for tens of seconds after that. I catched it still being +1 some 20 seconds later.

More later, including (I hope) the flarer ID after I have measured the image and have dan an ID run with the positions.

Update: the flaring object is identified as Metop-A, 06-044A. With thanks to Russell Eberst and Arnold Barmettler.

(click image to enlarge)

Thursday 19 April 2007

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.

Monday 16 April 2007

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.

Wednesday 11 April 2007

USA 129: 0.6s early and bright

USA 129 (96-072A) flared again to mag. -1 at about 19:56:50 UTC in the bum of Leo. It was some 0.6s early, so it looks like no manoeuvre yet. On the 9th perigee of the satellite coincided with equator crossing, which is usually the moment KH's manoeuvre.

Below image started some 10 seconds after the flare peak and shows USA 129 still bright, fading from +1 to +2, between Leo's bum and the coma cluster.

(click image to enlarge)

Monday 9 April 2007

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)

Friday 6 April 2007

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)

Tuesday 3 April 2007

My first USA 193 (06-057A) observation

I just observed the (reportedly failed) spysat USA 193 (06-057A) for the first time. Usually it stays too faint for me, but this time it was very bright, about mag. +1, just before eclipse entry, crossing Gemini. It was moving fast, a very fine sight. Below is the image I obtained.

Full report on the other observations of this fine evening later.

(click image to enlarge)

Monday 2 April 2007

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).