Thursday 29 April 2010

Yet another nice USA 186 KeyHole flare

I am running behind with reporting on my observations again. After my last report, I observed again on the 22nd and 26th of April. Targets were the usual suspects: the KH-12 KeyHoles USA 129 and USA 186, and two of the IGS objects (IGS 1B, and the IGS 5 r/b).

USA 186 is giving nice flare shows again. On the 22nd, I captured one of these flares (peaking at 21:11:36.7 UTC) on photograph. The same image also has the Kosmos 1515 r/b on it as a stray. See the image below, and the brightness profile of the flare below it:

click images to enlarge

Monday 19 April 2010

Another Keyhole flare

Although the skies were somewhat hazy, observations were conducted on the evenings of April 15th and 16th. Targets were the various IGS objects (1B, 5A, 5r/b), the Lacrosse 5 r/b, and the KH-12 Keyholes USA 129 and USA 186.

USA 186 was so friendly as to flare in my camera image on the 16th. The flare occurred at 20:43:40.75 UTC (Apr 16). Below is the image, and the resulting profile (with saturation at the peak). The two bright stars are the front stars of the pan of the Big Dipper, alpha and beta Uma.

click images to enlarge

Sunday 18 April 2010

Aircraft-less skies, but is the volcanic dust really visible?

Following the eruption of the Eyjafjallajoekull volcano of Iceland and the large amounts of dust it ejected into the atmosphere, airtraffic over NW Europe, including my country, has been completely halted. For four days now, this has resulted in unique airplane-less and contrail-less skies.

The sky is somewhat hazy for days here now, but is this due to the volcanic dust? Is it visible at all (as it was here after the 1991 Pinatubo eruption, causing pinkish-purple dusk skies)? Dutch news reports on Friday carried many photographs of red evening skies and red streaky clouds, purported to be the "volcanic dust". But all showed what to me looked like normal "evening red", sun-reddened cirrus clouds, and some even showed normal cumulonimbus!

I (and several Dutch astronomy and weather amateurs with me) have watched the evening skies the past days for anything unusual that could be attributed to the dust. But we failed to see anything more than what could very well be normal "evening red". Quite disappointing!

Below image was shot by me on Friday evening 16 April 2010 at about 18:29 UTC (20:29 CEST), some 10 minutes before sunset. Visible is a faint halo in the haze.

click image to enlarge

The orange is, in my opinion, normal evening red. And the halo: is it a "normal" halo in cirrus, or is it the "Ring of Bishop", due to dust?

The answer comes from a closer look. I have taken a part of the halo image, and increased the colour saturation to show the colour better. What can be seen (image below), is that the red/orange part of the spectrum is located at the inner side of the ring.

This means the ring is a halo in ice particles: in a dust-induced Bishop's ring, the red should be on the outside.

click image to enlarge

Wednesday 14 April 2010

Satellite rush hour

Over the past week I could observe on the evenings of April 8th, 11th and 12th. Several objects were captured: the KH-12 USA 186 (05-042A) on all three evenings, IGS 1B (03-009B) on the 8th and 12th, the KH-12 USA 129 (96-072A) and the IGS 5r/b on the 8th. USA 186 slowly flared to -1 on the 11th at 20:34:45 UTC.

In addition, a number of strays were captured, including yet another Breeze-M tank (09-016C, from the Eutelsat W2A launch) and a non-classified military object, the DMSP B5D2-2 (83-113A) military weather satellite. The latter flared, with the flare peak near 20:34:12.87 UTC (secondary peaks near 20:34:12.45 and 20:34:13.37 UTC).

The DMSP flare was captured as a stray in a rather uniquely satellite-crowded image that also shows the KH-12 USA 186 (the target), the mentioned Breeze-M tank (09-016C), and a third stray, the Kosmos 1531 r/b (84-003B) all in an area of only a few degrees! Below is the image in question (the DMSP is moving from top to bottom here, USA from bottom to top):

click image to enlarge

Below is the brightness profile of the DMSP flare derived from the image:

click diagram to enlarge

During observations, I had a spectator: Pippi the cat followed my activities with close attention from behind the window:

click image to enlarge

Tuesday 6 April 2010

Spring objects, a Keyhole manoeuvre and a flare of the IGS 5 rocket

After three weeks with cloudy and rainy weather, two consecutive evenings on a row finally allowed observations again on 4 and 5 April.

This is the time of the year that, like spring birds, some object re-appear from their winter hiding: the American KH-12 Keyholes, and the Japanese Intelligence Gathering Satellites (IGS).

Two KH-12 keyhole optical reconnaissance satellites were targetted the past two evenings: USA 129 (96-072A) and USA 186 (05-042A). USA 129 is of special interest these days, as it made a small manoeuvre early april raising it's orbit slightly. I captured it 8 seconds late relative to an early April elset on April 4th. An analysis of the pre- and post-manoeuvre elsets suggest the manoeuvre occurred on April 1st near 04:35 UTC while the satellite was passing the US west coast just after going through it's ascending node.

USA 129 flared to mag. 0 on April 5th, 20:05:08 UTC.

Below is an image of USA 129 rising through patchy thin clouds in Leo on April 4th, and it's sister craft USA 186 moving low in the east though Bootes on the same evening around the same time:

click images to enlarge

I also got my first images of this year of the Japanese IGS, optical and radar satellites. The defunct IGS 1B (03-009B) was imaged on April 4 and 5, and flared briefly to mag. 0 at 21:21:15 UTC on April 5 with a distinct orange colour. On April 5, the IGS 5A craft (09-066A) was imaged by me for the first time.

Below is an image of IGS 1B shot on April 4th:

click image to enlarge

I also captured the rocket from the 09-066 (IGS 5) launch: IGS 5r (09-066B). It shows flaring behaviour, as can be seen below from the photograph and the detail image, with the resulting brightness profile below that. The main brightness maximum in the image occurred at 21:44:06.9 UTC (April 5).

click images to enlarge