Tuesday, 6 November 2007

More comet 17P/Holmes

After a week of very bad weather, it cleared last evening. The skies were far from perfect (haze, and flying clouds), but I could snap a few pictures of comet 17P/Holmes again. The comet is a bit fainter now, and larger, but still naked eye.

I experimented with taking images with my Canon Digital Ixus pocket camera on maximum zoom on a fixed tripod. The maximum exposure to retain pinpoint stars turned out to be 5 seconds in this setting. I took a large number of such exposures, and then stacked 17 of them to simulate a 85 second exposure (1m 25s). The result was much better than I expected, and hence I am curious what the result would be whenever the sky would really be good:

(click image to enlarge)

Tuesday, 30 October 2007

Comet 17P/Holmes

After a long period of cloudy skies, it finally cleared last evening. Not in time to catch satellites, but in time to catch comet 17P/Holmes.

Comet 17P/Holmes dramatically brightened a week ago, from mag. +16 (!) to mag +2.5 (!!). That is spectacular and no other comet is known to do this this dramatically.

Yesterday the skies cleared only after the moon was already up. Nevertheless, and nothwithstanding my location in the middle of a town center, I could easily spot the comet with the naked eye as a bright "fuzzy" star just east of the alpha Persei group. In my 20 x 80 binoculars, it was a very bright nebulous globe. There is no sign of a tail, only a round coma some 20 arcminutes in size.

In wide field pictures, the object appears stellar due to this reason. Below image is a "stack" of three 10.7s images with my Canon Digital Ixus 400 pocket camera on a fixed tripod (so no guiding).

(click image to enlarge to full size)


Monday, 20 August 2007

Short session

Rainshowers dominate the weather since a few days. I did get a short period of clearings last night however, with very transparent sky. It enabled me to catch Lacrosse 5 (05-016A) on three images.

It did it's "disappearance trick" again at 22:30:31 UTC (Aug 19).

Tuesday, 14 August 2007

Abrixas rocket (99-022C) started to flash - UPDATED

On August 1st Bram Dorreman discovered that the SL-8 booster of the Abrixas launch (99-022C, #25723) that was previously stable, had started to flash. On his request I shot some trail images of it last night.

Conditions were not ideal, as there was cirrus in the sky. Yet the images (below) do show it's flashing behaviour, with a period of a few seconds (two maxima in each 10.7 second exposure). In the third image, Lacrosse 5 (05-016A) was captured as well.

UPDATE:
Careful measurement of the images yielded the following flash-intervals:

Photo #1:
4.0s
Photo #2:
4.6 s
Photo #3:
4.9s

(click images to enlarge)




Sunday, 12 August 2007

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):

(click image to enlarge)


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:

(click image to enlarge)


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

(click images to enlarge)


Friday, 10 August 2007

Observed Space Shuttle Endeavour STS-118 amidst flying clouds

Miracles do happen after all. This evening (9-10 August) was the only evening with an opportunity to spot the Space Shuttle Endeavour STS-118 on its way to the ISS. And I thought it was a lost case. Heavy cloud cover.

The first pass in deep twilight at 20:03 UTC was indeed lost. An unbroken cloud cover, and no hopes for the next and final pass, 21:37 UTC.

But Lo Behold....at 21:15 UTC I noted gaps in the cloud cover. I could see Vega and Arcturus. The situation was very dynamic, with parts of the sky opening and then filling up again in a matter of tens of seconds, the cloud cover moving very fast...but breaking up a little.

At 21:30 I was ready at the courtyard. At 21:34 I spotted the ISS, passing through the zenith very close to Vega. Three minutes to go for the Shuttle, and the zenith was filling up with clouds again.

21:36....I looked west, hoping to see it near Arcturus. Brief glimpse of the latter, but no luck regarding the Shuttle. Clouds occupied the west. Then moved my watch to the zenith. It was breaking open again. I could see Vega.

21:37....YES!!!!!! For maybe 20 seconds I see it, passing a bit south of Vega, fast and about magnitude 0, similar to Vega!

20 seconds and then it was gone in clouds again. Did not even attempt to photograph, it was futile.

But I saw it! :-)

Monday, 6 August 2007

Observing EAS (ISS deb), and checking out a new observing location

Yesterday evening around 21:02 UTC I observed EAS (the Early Ammonia Servicer, 98-067BA, #31928), the refridgerator-sized tank thrown away from the ISS during the July 23th EVA.

I first picked it up, naked eye, when it passed through northern Ophiuchus at about 50 degrees altitude. It was about mag. +4 to +4.5 at that time. It passed in between Altair and the arrow, and then on to Delphinus, where it rapidly grew fainter.

An attempt to observe the VSSA, another piece of debris jettisoned from ISS the 23th, 10 minutes earlier failed.

The observation was done from a new location. During a bycicle tour with my brother last Tuesday, I explored a part of the open polder to the south-east of my home. In recent years a number of bicycle trails have been constructed there, allowing quick and easy access.

I hit upon a spot some 6.5 km from my home, that seemed promising. No street lanterns for 1.5 km around, and full view down to horizon level a full 360 degrees around. Here's a 360 degree strip panorama I took Friday:

(click image to enlarge)


The trail visible is a footpath that crosses the bird sanctuary here. The landscape is a typical Dutch flat polder landscape. This part of the polder is 1.7 meter below sea level.

On bicycle, I can reach this location in 25 minutes. Which is reasonable enough.

Yesterday evening I checked it out by night. In fact I had planned to do some serious observing at the location, but upon arrival I discovered to my dismay that I had forgotten to put my DCF77 radio-controlled clock in my backpack. So I had no reliable time source with me. Bummer...

After darkness fell, the sky quality turned out to be reasonable. The urbanized west of my country where I live is notably affected by light pollution, even at the few rare spots of countryside like these left. Yet being some 5 km away from the nearest town is obviously better than being in the midst of a town (as Cospar 4353 is).

Around 21:40 UTC, with the sun at -16 degrees altitude, I did a limiting magnitude count in Draco, in the zenith. The first count resulted in +6.5, the second in +6.6. And that is quite good for this part of the country. I could see the milky way down to 35 degrees altitude in the south-southeast.

Light domes dominate the lower parts of the sky though. Worst (and plainly bad) is the northwest, the combined domes of Leiden and the hellishly illuminated Heineken brewery at 2.5 km distance. Alphen a/d Rijn creates a dome in the northeast, and the combined domes of Zoetermeer and The Hague can be seen in the south (the latter were perhaps more prominent last evening than on a normal night, as there was cirrus in this part of the sky). The east and southeast is nice though, and so seemed west.

The location is certainly good enough to do meteor observations and satellite observations. The light pollution in the northwest perhaps makes it not so ideal a spot for Aurora observation, although the north itself is good.

It is very deserted there at night. The only people who have business there at night are the people belonging to the farms in the area. So a good, quiet spot to observe undisturbed, and relatively safe I think.

In the future I plan to do meteor observing sessions here (with satellites as a by-product); and I plan to use this location to track objects of interest that remain too low in the sky for my usual observing location Cospar 4353. For example, future Shuttle MECO-orbit observations (during this part of its orbit, some 20 minutes after launch, the Shuttle and its already decoupled tank pass at about 24 degrees altitude for me). The new secondary location will probably get the designation Cospar 4354.

I observed the ISS twice that evening: first in deep twilight while biking towards the location, and then around 21:39 UTC when it made a fine zenith pass. The following image shows it in the zenith, near Lyra:

(click image to enlarge)


I made six 10.7 second images during that pass, and stitched them together to show the pass from horizon to horizon:

(click image to enlarge: 4000 pixel wide image!)


While I was biking towards the location in twilight, and close to it, a hare jumped out of the grass aside the bike-lane and ran in front of me for tens of yards. Going back in darkness, another startled hare threw itself in front of my wheels and I had to brake to avoid disaster.

Sunday, 5 August 2007

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.

(click image to enlarge)


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.

Saturday, 4 August 2007

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:


(click image to enlarge)

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.

Wednesday, 1 August 2007

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.

(click images to enlarge)







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.

(click image to enlarge)


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

(click image to enlarge)

Monday, 23 July 2007

Another fine night, USA 193 bright & a Lacrosse 3 flare

Friday evening and Sunday evening saw two other observing opportunities. On Friday it remained restricted to Lacrosse 3 & the Lacrosse 5 rk (97-064A & 05-016B), as clouds came in at a certain point (this made me miss a predicted -8 Iridium flare alas). I saw Lacrosse 3 (97-064A) flare to mag +0.5 however at 23:30:44 UTC (Jul 20).

Sunday night was very fine however, and I catched Lacrosse 3 & 4, plus IGS 4A/R2 (07-005A) and USA 193 (06-057A). The latter was quite bright (+0.5) while passing in the northwest. The second of the two images below shows it as it is just disappearing out of sight behind the roof. The other image shows IGS 4A/R2.

USA 193 was 2.3s early relative to Ted's elset 07202.04020244.

(click images to enlarge)




Note: the time indicated in above image is in error, apologies.

Thursday, 19 July 2007

Observing again

Last night was very clear, and I finally could get myself to observe again after a 2-month period of inactivity (see previous post).

In 3 hours observing time I catched a nice batch of objects: USA 193 (06-057A), IGS 4A/R2 (07-005A), Lacrosse 3 (97-064A), Lacrosse 4 (00-047A), the Lacrosse 5 rk (05-016B) and a nice -2 flare of Iridium 14 (99-032A). I also visually observed IGS 1B (03-009B) but the trail ends on the image were to marginal to measure.

Below pictures showing:

- the Japase radar reco satellite IGS 4A/R2 and the American radar reco satellitre Lacrosse 3 in one and the same image, in Cassiopeia;
- the flare of Iridium 14.

(click images to enlarge)




Note: the times listed in the Iridium flare picture are 10 seconds off from the real time

Thursday, 12 July 2007

Inoperative period

Just a note that SatTrackCam/Cospar 4353 due to circumstances has been inoperative for a while, and might continue to be so for a while. Apart from the very bad weather we are experiencing the past weeks, a reason for this is in a tragic personal loss affecting my life currently.

Sunday, 20 May 2007

IGS-es, USA 193, and other stuff during beautiful clear nights

SatTrackCam Leiden just experienced a few beautifully clear, dark & transparent nights. The result is a fine batch of positions on several objects, including Keyholes (USA 161), Lacrosses (3, 4 & 5), USA 193 and the old & new Japanese IGS-es. The latter include my first positions on IGS 4A/R2 (07-005A).

The first capture of the latter object was when I was waiting for its rocket launcher (IGS 4r/R2r, 07-005C) on the night of May 17-18. Suddenly a bright (+2) object appeared 2 minutes before 07-005C should, following a similar trajectory. I made a photograph and then found out it was the A component.

Due to a goof from my side I initially thought it was the optical satellite (due to it having the "A" designation, analogue to IGS 1A, 03-009A) and hence was surprised to find it was so bright. Only later I realized it is the (intrinsically brighter) radar sat.

Keyhole USA 161 (01-044A) was observed flaring on the 18th at 00:12:50 UTC (-1.5, slow) and 00:14:13 UTC (-1, short).

USA 193 (06-057A) was bright.

Lacrosse 5 (05-016A) was elusive. On the 18th, it initially was +2 low in the sky but then quickly faded beyond vision for much of the pass.

Below are trail images of the "new" IGS 4A/R2, it's rocket 4R/R2r cruising through Lyra, Lacrosse 3 cruising amongst the Coma cluster stars, and an Iridium flare in twilight.

(click images to enlarge)






Sunday, 13 May 2007

Composite image of a USA 161 pass

Below image is a composite of two 10.7 second images, 35 seconds apart, made during yesterday's USA 161 (01-044A) pass. It includes the flare image posted earlier.

The stitch of the two images was made with Hugin/PTStitcher, the same software I use for my daylight panorama images.

The flare effect is even more accentuated in this composite, and the wide angle (roughly 50 x 50 degrees) makes several constellations well recognizable.

The glare in the lower right corner is reflection from a lamp on the courtyard.

(this image is of course reduced in size and compressed compared to the original, hence the fainter stars are lost).

(click image to enlarge)

USA 161 flare, beautiful evening

Yesterday evening was very clear, thanks to a strong wind blowing the clouds away. I could observe until 3 am, when clouds came in again.

Highlight of the session was Keyhole satellite USA 161 (01-044A). It was very bright for much of its pass (about +2) and then flared to mag. -1.5 at 00:00:46 UTC. It was so nice to do that while the camera was open: image is below.

Other catches included Lacrosses 3 & 4 (97-064A & 00-047A) and IGS 1B (03-009B). One of the Lacrosse 3 images also captured a stray, which turned out to be the Kosmos 2292 SL-8 rocket (94-061B). Several other bright strays were seen, three of them flaring nicely, while preparing the camera.

I had USA 161 some 0.6s late, IGS 1B some 2.6s late, Lacrosse 4 some 0.4s late, and Lacrosse 3 some 0.3s early.


(click image to enlarge)

Thursday, 3 May 2007

Lacrosse 3

Phil Masding provided me with a number of potential flare time predictions for Lacrosse 3 (97-064A). The aim is to determine at what angle flares will be no longer visible.

Two of these predictions were for yesterday evening and as the sky was very clear again, I covered both.

At 21:30:38 UTC (2 seconds after the nominal prediction) and almost right in the zenith for me, Lacrosse 3 indeed "flared", albeit very modestly. The short increase in brightness was no more than say 0.5 magnitudes but discernable. Below is the image (visually, the "flare" was somewhat better discernable).

On the other hand, during the second predicted time (23:12:38) Lacrosse 3 did nothing, it was steady as usual.

(click image to enlarge)

Wednesday, 2 May 2007

First observation of one of the new IGS objects

I managed to observe one of the new Japanese IGS eastern plane objects for the first time this night (see image below). It concerned the rocket-booster, 07-005C (#30588), which amateur trackers name either IGS 4r or IGS R2r.

It made a zenith pass and was bright and easy, mag. +1.5 in the zenith and about +2 when passing close to Polaris. It was steady, no sign of tumbling.

(click image to enlarge)

Tuesday, 1 May 2007

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.

(click images to enlarge)


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.

(click image to enlarge)