Monday 30 March 2009

Iranian Safir 2 r/b still slowly flaring

Yesterday evening, the atmosphere was very dynamic, with short clear spells repeatedly giving way to fields of clouds.

Nothwithstanding these conditions, I managed to image the Keyhole USA 129 (96-072A) again, plus the Iranian rocket booster Safir 2 r/b (09-004B) that launched OMID in February. I imaged it earlier in the morning of 7 March.

At that time, it showed bright flares in a slow pattern. It is still doing so, as yesterday evening's images show. The time between the bright glints is slightly less than it was early this month. I determined a 31.7 second interval between two of the glints, with glint times at (March 29 UTC):

19:57:19.5 UTC
19:57:51.2 UTC

On March 7, the determined glint interval was 33.25 seconds.

Below are the two images of last evening, plus the brightness curves. The glints appear to be slightly asymetric, with a slightly more shallow fall-off of the brightness after the glint maximum:

(click images to enlarge)

Thursday 26 March 2009

More HEO object observations

Yesterday afternoon I was very tired and fell a sleep on the couch. I woke up to find it clear outside, and the LEO observation window largely gone by already.

So a bit later in the evening I targetted some HEO (High Earth Orbit) objects again with the EF 100/2.8 Macro USM lens: USA 200 (08-010A) in a Molniya orbit, and the rocket booster USA198r (07-060B) in a 4.9 revolutions/day orbit.

The latter was at an altitude of 13 800 km (8625 miles) and a distance of 15 300 km (9560 miles) from me over the Kaspian Sea when I imaged it.

(click images to enlarge)

Tuesday 24 March 2009

Nice pass of USA 129

The evening initially started clear. I observed the ISS, the Lacrosse 3 & 4 (97-064A & 00-047A) and the Keyhole USA 129 (96-072A).

Lacrosse 3 was very bright (+1) while descending to the west, showing multiple slow flares. USA 129 was very nice, +2.5 and grazing the tip of the Big Dipper's tail. It resulted in the nice picture below. The bright star grazed halfway by the trail is eta Uma, the tip of the Big dipper tail. Alcor and Mizar are in top. Movement is from righ to legt. The smudge at the left edge of the picture is clouds.

(click image to enlarge)

Sunday 22 March 2009

March 21 Iridium 33 flashes

Like yesterday and 4 days ago, I captured the Iridium 33 wreckage (97-051C) flashing again in a very regular pattern. Like the days before, the flash period was 4.66 seconds:

photo 1:


Photo 2:


Images with the flashes indicated by arrows below:

(click images to enlarge)

Saturday 21 March 2009

Very bright International Space Station (Updated)

This evening I observed a magnificent pass of the International Space Station (ISS), with the Shuttle docked to it.

At about 40 degrees altitude in the west, during its approach, it shortly became very bright. A conservative estimate by me placed it at at least magnitude -5; Leo Barhorst observing the same pass from Almere, some 30 km North of me, estimated magnitude -6. After that, it slightly fainted, remaining bright but not as bright as it had been in the west.

Update: telescopic images by Quintus Oostendorp on show that the brightening was due to the solar panels reflecting sunlight.

This brief brightening was captured by my camera. The Hyades are visible to the left, the Pleiades to the right.

(click image to enlarge)

More flashing Iridium 33 wreckage, ISS, USA 200 and other high objects

As I wrote in my previous post with the image of USA 129 flaring, yesterday evening I hauled a rich batch of objects.

It started in twilight with a nice pass of the International Space Station (ISS). The image below shows it rising through Orion:

(click image to enlarge)

Next I photographed passes of Lacrosse 3 (97-064A) and the NOSS 3-4 rocket (07-027B).

The wreckage of Iridium 33 (97-051C) was observed flashing again. Two photographs yielded five flashes, and like 3 days ago they fit a flash periodicity of 4.6 to 4.7 seconds. The timings were derived by measuring the flash positions astrometrically, and fitting the obtained positions to the most recent Iridium 33 tle. Here are the two images, with the flashes indicated:

(click images to enlarge)

I also targeted some HEO (High Earth Orbit) objects again, this time experimenting with different camera settings. USA 200 (08-010A) was captured again, this time somewhat better than 3 days ago:

(click image to enlarge)

I combined 4 of the images into an animated GIF, showing the movement of the sky and the satellite over a 1 minute period:

On the same image series I captured a piece of debris, USA 144 debris (99-028C), as a stray. In addition, I imaged another object in a Molniya orbit, USA 179 (04-034A) and the USA 198 rocket (07-060B) this evening.

USA 129 flaring

This evening I bagged a rich bag of objects. Amongst them was the Keyhole satellite USA 129 (96-072A), that treated me on a bright mag. -1 flare at 20;24:25 UTC (March 20) shortly after emerging from eclipse in Perseus. I captured the peak and descending brightness part on the image shown below.

(click image to enlarge)

The light-curve is saturated near it's peak:

(click image to enlarge)

Friday 20 March 2009

Imaging distant objects: USA 200

Recently, I bought a new lens for my camera: a Canon EF 100/2.8 Macro USM. As this lens has a larger diameter than the EF 50/2.5 Macro I use for my regular satellite imagery, it is able to capture fainter stellar objects. Of course, the Field of View (FOV) is half as small, which makes it less fit for imaging objects in LEO (Low Earth Orbit).

It is more suitable though for imaging distant objects in HEO (High Earth Orbit): satellites which are at thousands of kilometers altitude (including, but not restricted to, Geostationary satellites). The brightest of these are around magnitude +8.5.

Yesterday I did some first succesful experiments on one of those objects: USA 200 (08-010A, NROL 28), an NRO ELINT satellite launched on 13 March 2008. It is in a Molniya orbit and as I imaged it, it was at an altitude of 29 564 km above the earth, and a distance to me of about 29 920 km! Hovering (well: not really. It is slowly moving in its orbit) high over Iceland at that moment, it keeps a watchful signals eye over the northern Atlantic and arctic.

I shot a series of 20 second exposures, from stationary tripod. The satellite showed some movement during these exposures. below photograph shows one of the images: the satellite has made a faint short trail perpendicular to the star trails.

(click image to enlarge)

The images below show the orbit of USA 200. The Molniya-type orbit means it orbits about twice a day, spending only little time in its perigee at low altitude over the southern hemisphere, and most of its time in the hight altitude parts of its orbit over the high northern hemisphere, its surveillance area.

(click images to enlarge)

Wednesday 18 March 2009

More flashes from the Iridium 33 wreckage

Yesterday evening, after observing the exciting ISS-Shuttle duo pass (see previous post), I tried to observe flashes from the Iridium 33 wreckage (97-051C) again. Simone had provided some experimental predictions and asked for verification.

The Iridium 33 wreckage did flare: two very bright flashes (both around mag. -1) seen naked eye, and two fainter ones (+4?) found on a photograph. They were off from the experimental predictions, but still cool!

The two -1 naked eye flashed were observed at 17 March, 20:06:56 ± 1s and 20:07:02 ± 5sUTC. The two photographic fainter flashes/glints occurred at 20:07:15.7 and 20:07:20.4 UTC. The time between the latter two is 4.7 seconds, and the first two (the naked eye ones) within their timing uncertainties fit a similar 4.7 second period.

The image with the two faint photographic flashes is below:

(click image to enlarge)

Tuesday 17 March 2009

Magnificent view of Shuttle and ISS just before docking!

I had a pass of the Space Shuttle Discovery STS-119 and the ISS this evening about one hour before they docked. This meant they were moving as a very close pair. The pass was around 19:10 UTC at 25 degrees altitude.

It was a beautiful sight, as the pair rose in the southwest and then majestically sailed past Sirius. Here's a picture:

(click image to enlarge)

The Shuttle is the object slightly fainter and lower in the sky. Movement is from right to left. Here's a second picture:

(click image to enlarge)

Sunday 15 March 2009

Iridium 33 wreckage photographed, with +4 glint

This evening was quite clear, and I decided to employ my new Canon EF 100/2.8 USM Macro lens to image a pass of the Iridium 33 main wreckage (97-051C). This lens has a bigger aperture than the EF 50/2.5 Marco I normally use, and hence is better for faint objects.

I was lucky and not only captured the very faint, irregular trail of the Iridium 33 wreckage: but also a short glint to mag. +4 at about 19:29:51 UTC (15 March), which I also observed with the naked eye.

The image is below. The inset shows the short glint, close to the end of the trail.

(click image to enlarge)

Friday 13 March 2009

A close call for the ISS

Shortly after the collision of Iridium 33 and Kosmos 2251, the news agencies are buzzing with a close call of the International Space Station and a piece of space debris. Astro/Kosmonauts in the station shortly evacuated to their Soyuz re-entry capsule for safety reasons.

The piece of space debris in question was 93-032D (25090), a piece of a PAM-D rocket engine, part of the launch of the Navstar 32 GPS satellite on 13 May 1993. It is small, but even small can be lethal to the ISS. The nominal orbits for the ISS and the space debris piece have it pass as close as within 2.4 km of each other at 12 March, 16:39:41 UTC. The close encounter occurred over the southern Atlantic, near the southernwest coast of Africa.

(click images to enlarge)

Wednesday 11 March 2009

Iridium 33 and Kosmos 2251 wreckages observed

I visually observed the main wrecks of both Iridium 33 and Kosmos 2251 with the Meade ETX-70 (7 cm F5 refractor) this evening.

The Iridium 33 wreckage (24946, 97-051C) was easy to see and notably irregular in brightness, with many short flashes (several per second, with a brighter one approximately each second. This is an estimate: I did not time them). I observed it as it passed close to Pollux near 19:55:10 UTC (11 March). At its brightest it might have been +6 or +6.5. I did not observe the kind of bright flares as reported by Simone from Italy yesterday.

The Kosmos 2251 wreckage (22675, 93-036A) was much fainter, about +8 at its brightest as it passed close to alpha Uma at 20:11:30 UTC. It too was irregular, but its brightness variation seemed slightly slower than that of the Iridium 33 wreckage.

I also observed Lacrosse 3 in twilight and got 6 positions on it.

Saturday 7 March 2009

An Iranian rocket (Safir 2 r/b)

Weather finally allowed me to observe one of the new Iranian objects from the February 2nd launch. It concerned the rocket booster from the launch, the Safir 2 r/b (09-004B).

Conditions were not perfect (somewhat hazy), but the rocket booster was well visible and I captured it on two images (see below). It showed a clear very slow amplitude brightness variation (amplitude >20 seconds), going between mag. +3 and near-invisibility for the naked eye (> +4). Around the brightness peak it gives a short bright glint. Both my photographs captured such a glint.

(update) Based on the two pictures, and assuming I didn't miss a glint in between them, the glint period is 33.25 seconds, with glints at:

7 Mar 2009 04:26:12.60 UTC
7 Mar 2009 04:26:45.85 UTC

Below the two pictures (as usual, Canon EOS 450D @ 800 ISO + EF 50/2.5 Macro @ F2.8), and the brightness profiles for these trails.

(click images to enlarge)

Sunday 1 March 2009

Lacrosse 5 passing alpha Persei

Earlier this week, on February the 24th, the generally very bad weather of this moment gave way to a short period of clear skies after dusk. This allowed me to obtain some positions on the bright SAR satellite Lacrosse 5 (05-016A) and it's spent rocket booster Lacrosse 5r (05-016B).

Below is an image showing Lacrosse 5 passing close to alpha Persei and the alpha Persei star association.

(click image to enlarge)