ENVISAT and other satellites flaring over the Italian Dolomites

During the second half of July, I travelled through northern Italy, including an 8-day mountain hike from mountain hut to mountain hut through the high Alpine parts (up to 2770 m) of the Rosengarten Dolomites. The latter mountains are truely marvelous, and perhaps the most beautiful mountains I have ever seen.

During two clear evenings I did some limited astrophotography: limited, as because of weight considerations I had only two lenses with me  (a Canon EF 100mm Macro and a Tamron 17-50mm zoom) . After all, we already had to carry 16 kg on our backs every day while scaling the mountain.

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The image above was shot at 2238m altitude from Rifugio Vajolet on July 23rd. It shows ENVISAT (02-009A) flaring. Since contact with this legendary Europe remote sensing satellite was lost on 8 April 2012, it appears to have started to tumble. Two brightness maxima (one brighter and one fainter preceding it) are visible on the original of the above 30 second exposure, and other (faint) maxima are visible on an earlier and on subsequent images.

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A 45 image series (30s exposure each) from the same location was used to create the above image of startrails circling the celestial pole. The mountain at right is the 3004m high Kesselkügel.

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A few days earlier (16 July), while at lower altitude (1188m) in Aldein (Aldino) where we visited the nearby Bletterbachschlucht, I shot this image of a double Iridium flare. The brighter of the two is Iridium 63, the other one is Iridium 14. The classified Japanese satellite IGS 7A (11-075A) can be seen as well as a fainter steady trail near the center of the image (the original image has 3 more very faint satellite trails as well). The bright star top right is Arcturus.

All images were made with a Canon EOS 60D at 2000 ISO (and part of image series driven by a programmable timer) using a Tamron 2.8/17-50mm set at 17mm.

The Lacrosse 5 "disappearance trick", and a BWGS meeting

On Saturday 26 September, a small number of BWGS satellite observers gathered at the house-boat of Leo Barhorst (Cospar 4253) at Almere. Present were, besides Leo Barhorst, BWGS president Bram Dorreman and me. A number of active BWGS observers alas could not come, hence the rather small group this time.

In the afternoon we exchanged some information, looked at some software, my collection of "black space program" mission, launch and unit patches, and Leo's collection of space-related postal stamps. I demonstrated how I astrometrically measure my satellite photographs for positions, and how I get brightness curves from an image.

The plan was to try some joint observations that evening (we could stay for the night at Leo's boat), and as it was sunny, we started preparations in the early evening. I took below photograph of Leo (seen frontal) and Bram (seen on the back) while they were making their preparations

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The sky was not perfect (and would progressively deteriorate later that evening). From a small green a few tens of yards from Leo's boat, we started by watching Iridium 80 flare to mag. -3.5 close to epsilon Cyg in the eastern wingtip of Cygnus. I took the picture below, a 10-second exposure with the EF 100/2.8 Macro USM:

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Immediately after that I rushed to re-aim the camera and capture the USA 144 decoy (99-028C) passing close to vega in the next minute. Predictions had put the track just west of Vega, and while Bram and Leo were watching there with binoculars I made a series of images. Strangely enough, Bram and leo did not pick it up: and the reason was, after a look at my photographs, that it passed east of Vega, not west! After a puzzled "huh?!?" it dawned upon me: the coordinates of my prediction software were still set on my Leiden locality!

Next up were the objects related to the recent launch of a Russian Meteor weather satellite. Bram and Leo indeed picked one up with their binoculars.

Shortly after that, we watched a nice pass of the SAR Lacrosse 5 (05-016A) with the naked eye. As we watched it, it did it's infamous "disappearance trick" again. It did so during an exposure, that captured the quick loss of brightness very well. It was the first time I imaged the phenomena with my Canon EOS 450 DSLR. It yielded this very nice diagram of the brightness variation (constructed from two images):

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Note how quick the brightness drop is (it takes a mere 4 seconds) and how sharp the turnpoints in the diagram are.

Next up were passes of the KH-12 optical reconnaisance Keyhole USA 186 (05-042A), which briefly attained naked eye visibility and was of course photographed; and the NOSS 3-3 duo (05-004A & C) which were faintly visible to the naked eye as they crossed Cygnus, and yielded two very fine pictures, one of which is below:

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Note the difference in brightness between the A and C components. (note: I mistakenly labelled the C component as 'B' in the image...)

After this, Leo and Bram observed the NOSS 3-3 rocket, which is a flasher. As the sky quality rapidly deteriorated, we called it quits after that and went inside to reduce the observational data.

It was nice to meet and observe together. Leo was a perfect host, and his cat Bankie kept my feet warm later that night.

Aftermath of a space collision

Over 200 fragments of the Feb 10th collision between Kosmos 2251 and Iridium 33 have now been catalogued. Together, they form two impressive orbital planes filled with debris. The amount of Kosmos 2251 debris catalogued so far is about twice as large as that for Iridium 33 - it seems the Kosmos took the most serious blow.

Most of this debris will stay up for tens of years. About 6% of the Kosmos and 3% of the Iridium debris will decay in the next 2.7 years.

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In Memoriam: Iridium 33

On 10 February 2009 at 16:56:00 UTC, Iridium 33 (97-051C) collided in orbit with the defunct Russian Kosmos 2251 satellite (93-036A). The collision occurred at 789 km altitude over the Siberian arctic, near 97.9 E, 72.5 N, with an orbital interception angle of 83.5 degrees. A cloud of rapidly spreading debris is now all that remains.

The collision occured at roughly the same altitude as the Chinese ASAT test on Fengyun 1C, and the resulting scenario for the debris cloud will be roughly similar to the latter event. An analysis of the Fengyun 1C debris field formation by Kelso can be read here.

On May 18th 2007, when Iridium 33 was still happy, alive and flaring, I shot the picture below:

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Flares, strays and spy sats

The evenings of September 1st and 3rd saw a nice catch of satellites. My new camera system (Canon EOS 450D + EF 50/2.5 Macro) really is a sat magnet, which is also apparent by the number of strays captured in images with classified objects.

Objects imaged these nights include the KeyHole satellites USA 129 (96-072A) and USA 186 (05-042A), the SAR sats Lacrosse 4 & 5 (00-047A and 05-016A), and the Japanese sats IGS 1A and IGS 1B (03-009A and 03-009B).

IGS 1A is an example of a sat that would normally be beyond reach of my older camera system, but is well within reach now. The KeyHoles are captured much more easily now too.

Moreover, the quality of the positions obtained seems to be better. This is due to both the better image quality (less ambiguity in the start and end of the trails, as the images are much less noisy and the trails brighter), and to a much better, consistent timing behaviour of this camera.

Because of the more narrow field of the EF 50/2.5 Macro lens, I employ the laser (the same I use for pointing my telescope) to point the camera. Below is a photograph of what this looks like (although in reality the beam is less bright visually: this is the result of a 10 second exposure). Stars visible are from Cassiopeia and Perseus, with the double cluster visible just beneath the laser beam.

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On September 1st, I watched Lacrosse 5 (05-016A) together with my neighbour. It was nice and bright, and did it's infamous "disappearance trick" while just past the zenith. I had just been explaining this peculiar behaviour to my neighbour, so he got a nice demonstration!

Some nice flares were captured too these evenings. Below images show a mag. -8 flare of Iridium 72 on 3 Sep 20:15:29 UTC, and a brief mag 0 flare/glint by KeyHole satellite USA 129 (96-072A) at 20:33:34 UTC on the same evening. The curtain-like structure on the Iridium image is due to a moving patch of clouds.

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Several strays were captured as well, mostly spent Russian rocket boosters.

Lacrosse 2 and a splendid -7.5 Iridium 5 flare

After an overcast day with rain, holes started to appear in the cloud cover in the evening. They allowed me to capture Lacrosse 2 (91-017A) in a blue twilight sky, followed by a splendid magnitude -7.5 flare of Iridium 5 close to Arcturus seen through thin hazy clouds.

Lacrosse 2 flared as well to mag. -1 at 21:34:42 UTC (Jul 5).

The top image below shows Lacrosse 2 in twilight. The second picture shows the Iridium flare, with Arcturus at left.

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Iridium flare, and a new camera

Last 1.5 month has seen very little activity here. Reasons behind that were a period with a stationary occlusal front bringing lots of clouds (and rain); a period where I was physically not entirely well; and the very late time at which at this time of the year it gets dark at my latitude (after local midnight only), which combined with my work schedule doesn't allow much observing mid-week.

Yesterday I did stay up until after midnight though. Because a new "toy" has arrived at Cospar 4353: a Canon EOS 450D DSLR camera, result of the investment of a tax return.

Below is an image I shot of a mag. -0.5 flare of Iridium 8 I shot last night. I used the EF-S 18-55 IS kit lens for it, at 18 mm F3.5 and ISO 800 with 15 seconds exposure.

Another lens, an EF 2.5/50 Macro which according to my friends yields superb results with astrophotography, arrives somewhere this weekend.

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Iridium flares

Weather and other occupations didn't allow me much observing the past two weeks. I did get a few positions last week, on the 8th and 11th. On the 8th it were Lacrosse 2 (91-017A) and three of the NOSS-2-3 components (96-029C, D & E). Yesterday (the 11th) it wereIGS1A and 1B (03-009A & B).

I also made a few photographs of Iridium flares with the new Ixus 75 camera. Two of them are shown below. So far, it seems my new camera has a timing lag of 0.9 seconds. Unlike the Ixus 400, the 10 second exposure setting really is 10 seconds.

The Ixus 75 images are much sharper than those of the Ixus 400. I have some suspicion though that they show less faint stars than the Ixus 400 images.

Below are two Iridium flare pictures (Iridium 43 on the 8th, and Iridium 98 on the 11th). Also given are their brightness profiles.

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Lacrosse 5r, ISS, Iridium flares and comet 17P/Holmes

Yesterday was frosty and clear, albeit a bit moisty at the start of the night. A first quarter moon was low in the south.

I observed a nice pass of the International Space Station, two Iridium flares, and a pass of the Lacrosse 5 Rocket (05-016B).

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Comet 17P/Holmes has grown large and very diffuse and was the target after midnight, when the sky had become less moist and the moon had set. It could still be seen naked eye, but with more difficulty than previously. It is about a degree wide. Below is a stack of 6 imges of 10 seconds each in wide-field; and a stack of 55 images of 5 seconds each at maximum zoom.

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Lacrosse 5 flaring, and another Iridium flare

A gale today had blown the skies clear by dusk. I observed Lacrosse 5 (05-016A) and saw it flare to mag. 0 at 16:49:08 +/- 5s UTC. I catched it on photograph with an exposure starting only some 2 seconds after the flare peak: but a strong gust of wind rocked the camera tripod during the exposure, leading to a disrupted trail image.

I was more lucky half an hour later, when Iridium 7 (97-020B) flared to mag. -2.5. It resulted in a nice picture:

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I combined this evenings Iridium 7 flare picture with that of the Iridium 97 flare yesterday. It nicely shows how the geometry of the orbit and fixed attitude for the Iridium constellation makes them flare at more or less the same location:

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Iridium 97 mag. -2 flare

Short clearings amidst flying clouds allowed me to image this mag. -2 flare of Iridium 97 (02-031A) flaring at 17:25:57 UTC. A few minutes earlier, Iridium 36 (97-056C) failed to deliver a predicted flare however.

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Perseids and satellites from the new outpost "De Wilck" (Cospar 4354)

Last night was the inaugural night of my new secondary 'outpost' in the polder at De Wilck (see previous post here), now Cospar 4354. I spent some 3.5 hours there, observing the Perseid meteor shower, and satellites.

I arrived at 00:15 CEST (22:15 UTC). It was quite clear at that moment and I counted a limiting magnitude of +6.5 in the zenith. While setting up and waiting for two Iridium flares (Iridium 14 and 72) thin ground-fog appeared however, which would come and go the next 3 hours. As a result the limiting magnitude dropped between 0.1 and 0.4 magnitudes. The layer was thin, the top at perhaps 1.5 to 2 meter only. It didn't really hamper observations, even though the limiting magnitude dropped a bit.

I first observed two Iridium flares. Iridium 14 (99-032A) with a flare near -2 was the first. The flare peaked several seconds after the prediction. The second one, 3 minutes later, did peak on the predicted time and was much more spectacular. It concerned Iridium 72 (98-032B) flaring to mag. -7. Below is the scenic photograph that resulted (the ground-fog adds a misty atmosphere):

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Following this I started my meteor observing, interrupted by short breaks in order to catch Lacrosse 5 (05-016A), IGS 4A/R2 (07-005A) and the IGS 4r (07-005C).

Lacrosse 5 (05-016A) was nice and bright (from +2 to +1.5) when ascending in the southwest, and did it's infamous disappearance trick again at 22:54:35 UTC. Following this it shortly re-appeared at 22:56:08 UTC for only a few seconds at about mag. +3.5.

IGS 4A/R2 (07-005A), the Japanese radar reco satellite, was eagerly awaited as it appears to have manoeuvred a few days ago according to Pierre. It appeared out of eclipse at the Andromeda/Perseus border and I got 4 positions. Below image shows it in Northern Perseus:

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Thirty minutes later, the IGS 4 rocket (07-005C) was observed. It produced a short bright surprise flare to mag. -1 in Umi at 00:42:00 UTC, fading rapidly after that. Three positions were obtained.

A couple of strays were seen while observing meteors. A weird stroboscopically flaring satellite (multiple flashes per second) moved near alpha And at 23:15:00 UTC. Another satellite flared to -2 and shortly after that again to 0 at 00:26:00 UTC near Polaris.

This was my first meteor session since illness forced a stop 4 years ago, and it felt great to be out under a starry sky again, watching meteors. The location turns out to be adequate and quiet. And even with ground fog, conditions still were reasonable. Hence, I will certainly return more often here. I did note however that I am still not fit to do an entire observing night. Having started the meteor session at 22:35 UTC, I stopped at 1:30 UTC because I was starting to feel very tired (and still had a 25 minute bicycle ride to do).

2.28 hours of effective observing time with limiting magnitudes between +6.4 and +6.1 yielded me 130 meteors, 90 of which were Perseids. The meteor activity was nice, but they were rather faint, with not a single fireball among them. The kappa Cygnids were recognizable too, and I logged two delta Aquariids.

Before biking to De Wilck, I shot images of the 20:45 UTC ISS pass in twilight from my home (Cospar 4353). ISS was bright, around mag. -4 in the zenit. I also observed USA 193 (06-057A) but the trails on the two images are very marginal. They contain a faint stray too (which I still have to identify when I am less tired).

Update: the stray mentioned in the last sentence turns out to be 90-046B, the Kosmos 2082 rocket body

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Another -8 Iridium flare

Bright Iridium flares never are a bore, and the summer season with its long twilight at my latitude has plenty of them.

Last night at 22:56:24 UTC (Aug 4) I observed Iridium 21 (99-032B) flare brilliantly to mag. -8 in Ophiuchus. Like 31 July's Iridium 74 flare (which occurred in roughly the same sky position), it visually had a yellowish colour.

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It was a beautifully clear, warm night. In addition to Iridium 21, I also observed a nice bright pass of ISS, reaching mag. -3. Another object that never bores. On the classified front, I observed IGS 1B (03-009B) and the NOSS 3-4 Centaur rocket (07-027B) again.

While imaging IGS 1B, certain noises through an open window nearby reminded me that on a beautiful night like this, some other people also engage in their own particular pleasurable hobbies too... ;-)

As I was very tired, I stopped after observing and photographing the Iridium flare.

NOSS 3-4 Centaur rocket brightness variation

Last night (3-4 August) I observed the NOSS 3-4 Centaur rocket stage (07-027B) again over a large part of its trajectory. I obtained a number of images (yielding 10 positions), and they nicely show the varying brightness of the rocket stage due to its tumbling. It can be well seen in below series of snapshots, which were taken at approximately 1 minute intervals:

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note added 05/08: the variation is not in each sub-image, but between the images. Basically, the sequence for these four is: picture #1 bright trail; picture #2 faint trail; picture #3 bright trail again; picture #4 faint trail again.

Apart from 07-027B, I also observed IGS 1B (03-009B) and a mag. -0.5 flare of Iridium 74 (98-032D). Around the time of the Iridium flare however, cirrus clouds moved in and I stopped observing.

The NOSS 3-4 centaur rocket (07-027B): a nice new object

June 15 2007 saw the launch of NRO's NOSS 3-4 satellites. They belong to the new US Navy twin satellite constellation (the old NOSS-es were trio's) the purpose of which is to pinpoint the origin of shipping communications.

The payload couple (07-027A & C) and the last stage NOSS 3-4r Centaur rocket (07-027B) are now being tracked by amateurs. For me, the Centaur stage (07-027B) is the most interesting, as it is bright. It is also slow moving. And making zenith-passes near midnight for my station at the moment. Which all makes it a fine photographic target.

The object slowly tumbles, as is apparent from a very slow variation in magnitude. Over the course of a minute or so, it varies between mag. +4 and +1.5 on a zenith pass.

Last week I observed the object for the first time, on 3 different nights including last night (I observed a fine list of other objects from my regular observing program as well on these nights).

On the first two nights I was greatly hampered by drifting fields of cumuli but could nevertheless capture the object through gaps in the cloud cover. Last night was clear and I could follow it along a large part of its trajectory, the slow amplitude in brightness due to the tumbling being very apparent. Below three images show the object as captured on the nights of July 29-30, 30-31 and July 31-Aug 1.

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Last night the first (out of 3) image of the object suffered from an attempted counter-intelligence attack though ;-)

Frenkie, the cat of my neighbour, joined me at the courtyard that night and started to hug me and my camera tripod in the way cats do. As a result the first image I obtained contained a wobbled satellite trail and I did not measure it. I chased away Frenkie, as lovely as he is, and shot two more images one of which is shown above.

(Frenkie is now suspected to be back at his CIA headquarters, reporting to his commander, who carefully trained him: "Meooow, mission only partly accomplished").

I also had an Iridium flare path center coming almost exactly over my house last night. It concerned Iridium 67 (98-021F) and it flared brilliantly to at least mag. -8. The flare had a distinct yellow colour.

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The previous night also saw a nice (less bright: mag -1) flare of Iridium 64 (98-021C):

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Flares of USA 186, Lacrosse 3 and an Iridium

Another very clear evening in which the sky was so transparent that the moon was no real hindrance.

I observed 3 flares. Iridium 47 flared to mag. -1.5 in twilight at virtually the same spot as yesterday's -6 Iridium 25 flare. The picture is below.

At 20:52:23 UTC I saw USA 186 (05-052A), which was faint during the rest of its pass, flare to mag. -2 in the north. Alas not on photograph.

I was more lucky with Lacrosse 3 (97-064A) which flared to mag. +1.5 at 21:01:34 UTC while the camera was open (see below image, the bright star left is Arcturus).

I also observed IGS 1B (03-009B), on a zenith pass. It was faint again and irregular, quite unlike its visibility in earlier years.

I am very tired currently, but given the unusually clear skies I might try some additional observations this morning on the new IGS objects.

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Iridium flare season

It was very transparent last night, to the extend that the full moon didn't seem to hamper much. Alas I had not much opportunity to observe, as I was franticly making the last final edits to a research proposal, the dead-line of which was this afternoon.

I did catch this fine mag. -6 flare of Iridium 25 at 51 degree elevation in the east though (see image below). The season of many bright Iridium flares high in the sky has started again

Main focus at the moment is still on gathering material to calibrate the times of my camera. Currently a recalibration of -0.30 s (as opposed to the -0.35s I initially took) seems to get times in line.

Interestingly, this -0.30s means the time calibration value is similar again to that which I initially obtained way back in August 2005. It then jumped by 0.3s after I made a change in my camera settings in September 2005. Apparently now it is back at the old value again. I did not consciously make another change in my camera settings, but have accessed the camera recently with Canon software to test that software, and apparently it did change settings.

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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).

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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....

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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:

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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:

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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:

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

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