For anyone interested in having a go at modelling the enigmatic "disappearance" events of Lacrosse 5 (05-016A): in addition to the list maintained by Philip Masding at his website, I have posted my own timings of such disappearance event over the past year at:
http://home.wanadoo.nl/marco.langbroek/L5d_4353.txt
The list on that URL ( a link to it is in the right-hand sidebar of this blog too) will be updated whenever I time a new event of this type.
Friday, 26 January 2007
Wednesday, 24 January 2007
Another Iridium flare, Lacrosse 4 and another Lacrosse 5 "disappearance"
This evening another Iridium flare was predicted for my location. Iridium 76 (98-048B, #25432) was predicted to flare to mag. -4.8 at 18:16:41.7 UTC at virtually the same sky location as yesterdays Iridium 03 flare.
The flare was very fine again. A field of clouds passing by added a dramatic touch to the scene, as can be seen in the photograph below.
A quarter of an hour earlier, I observed and photographed a fine pass of Lacrosse 4 (00-047A, #26473). It passed close to the Pleiades cluster again, making for a scenic picture (see below). I obtained two images, hence 4 points. Lacrosse 4 was some 0.35s late.
A minute after the Iridium 76 flare, I switched my attention to Lacrosse 5 (05-016A, #28646). It was bright as it climbed from Cygnus through Andromeda to Cassiopeia. Just before my camera opened for the first exposure, it however did its "disappearance trick" again, this time at 18:18:18 UTC (ugh, if you are nutty enough to believe in numerology (which I don't) that is a Devilish time to do trics for a clandestine sat....6+6+6:6+6+6:6+6+6 !).
The flare was very fine again. A field of clouds passing by added a dramatic touch to the scene, as can be seen in the photograph below.
(click image to enlarge)
A quarter of an hour earlier, I observed and photographed a fine pass of Lacrosse 4 (00-047A, #26473). It passed close to the Pleiades cluster again, making for a scenic picture (see below). I obtained two images, hence 4 points. Lacrosse 4 was some 0.35s late.
(click image to enlarge)
A minute after the Iridium 76 flare, I switched my attention to Lacrosse 5 (05-016A, #28646). It was bright as it climbed from Cygnus through Andromeda to Cassiopeia. Just before my camera opened for the first exposure, it however did its "disappearance trick" again, this time at 18:18:18 UTC (ugh, if you are nutty enough to believe in numerology (which I don't) that is a Devilish time to do trics for a clandestine sat....6+6+6:6+6+6:6+6+6 !).
Odds of a mag. -7.5 Iridium flare, and twice Lacrosse 5 its tricks
Another clear (and cold) evening, although clouds began to appear at 19h UTC. Positions were obtained on Lacrosse 5 (05-016A, #28646) and Lacrosse 4 (00-047A, #26473), as well as Iridium 03 (98-048A, #25431).
Highlight of the evening was a splendid magnitude -7.5 flare by Iridium 03 at an altitude of 44 degrees and azimuth 28 degrees (north-northeast) at 18:22:50.8 UTC.
The image above was shot from the street in front of the almshouse complex (it was just too low in the sky to be visible from the courtyard of the complex) with a 10.7s exposure between 18:22:47.1-18:22:57.8 UTC. The flare had a predicted brightness of mag. -7.5, and indeed must have been in that order. The center of the flare path was 4.8 km West of me (while the Iridium satellite was over Denmark, at 785 km altitude and a range of 1069 km north-northwest of me).
Chance had it that the people from Grimbergen observatory in Belgium (Philippe Mollet et al.) located 135.9 km south of my location, observed the same flare from the same Iridium. While I had the center of the flarepath at 4.8 km West of me at 18:22:50.8 UTC, they had the center of the flare path at 4.6 km East of them at 18:22:28.9 UTC. So the geometries were virtually the same (with a predicted brightness of mag. -7.7 for Grimbergen, versus -7.5 for me), they having the flare maximum 20.9s earlier in time than me. What a coincidence!
I observed one pass of Lacrosse 4 (two good images, yielding 4 positions), and two of Lacrosse 5 (3 images, half of the points dropped because of too faint trail ends, hence 3 positions).
Lacrosse 5 (05-016A, #28646) did its "disappearance trick"again at both passes. During the first pass it did it at 17:30:44 UTC, while the camera was open for its second exposure, resulting in the image below. The true end of the trail at the end of the exposure should be at the right of the star near the trail end: it is at the left in the image, as the satellite dropped below the imaging treshold in brightness before the end of the exposure. The drop was rather fast.
A few tens of seconds after it, I could see the satellite as a very faint object (mag. +4 to +4.5) with the naked eye (before the drop in brightness it had been +2). A third image exposed between 17:31:46.1-17:31:56.8 UTC shows a very faint trail after some image manipulation (see below)
Lacrosse 5 did the same trick again during a second pass. This time it disappeared some 5 seconds before my camera opened, at 19:13:15 UTC.
Highlight of the evening was a splendid magnitude -7.5 flare by Iridium 03 at an altitude of 44 degrees and azimuth 28 degrees (north-northeast) at 18:22:50.8 UTC.
(click image to enlarge)
The image above was shot from the street in front of the almshouse complex (it was just too low in the sky to be visible from the courtyard of the complex) with a 10.7s exposure between 18:22:47.1-18:22:57.8 UTC. The flare had a predicted brightness of mag. -7.5, and indeed must have been in that order. The center of the flare path was 4.8 km West of me (while the Iridium satellite was over Denmark, at 785 km altitude and a range of 1069 km north-northwest of me).
Chance had it that the people from Grimbergen observatory in Belgium (Philippe Mollet et al.) located 135.9 km south of my location, observed the same flare from the same Iridium. While I had the center of the flarepath at 4.8 km West of me at 18:22:50.8 UTC, they had the center of the flare path at 4.6 km East of them at 18:22:28.9 UTC. So the geometries were virtually the same (with a predicted brightness of mag. -7.7 for Grimbergen, versus -7.5 for me), they having the flare maximum 20.9s earlier in time than me. What a coincidence!
I observed one pass of Lacrosse 4 (two good images, yielding 4 positions), and two of Lacrosse 5 (3 images, half of the points dropped because of too faint trail ends, hence 3 positions).
Lacrosse 5 (05-016A, #28646) did its "disappearance trick"again at both passes. During the first pass it did it at 17:30:44 UTC, while the camera was open for its second exposure, resulting in the image below. The true end of the trail at the end of the exposure should be at the right of the star near the trail end: it is at the left in the image, as the satellite dropped below the imaging treshold in brightness before the end of the exposure. The drop was rather fast.
(click image to enlarge)
A few tens of seconds after it, I could see the satellite as a very faint object (mag. +4 to +4.5) with the naked eye (before the drop in brightness it had been +2). A third image exposed between 17:31:46.1-17:31:56.8 UTC shows a very faint trail after some image manipulation (see below)
(click image to enlarge)
Lacrosse 5 did the same trick again during a second pass. This time it disappeared some 5 seconds before my camera opened, at 19:13:15 UTC.
Monday, 22 January 2007
Lacrosse 5 tricks again, and Lacrosse 4 cruising near the Pleiades
Another clear (and cold) evening. I observed the radar birds Lacrosse 5 (05-016A) and Lacrosse 4 (00-047A) within a minute of each other (making the imaging quite hectic, having to swap the camera to a different part of the sky within a few tens of seconds).
I obtained two images (hence 4 positions) on Lacrosse 4, the first one of which captured the sat cruising at a steady mag. +3 close to the Pleiades cluster (image below):
A minute earlier I had captured Lacrosse 5 in the act of doing its infamous "disappearance trick" again. The image below shows it fading rapidly, in fact the apparent trail end on the image predates the end of the exposure. Visually, I timed the disappearance at about 18:25:30 (+/- 2s) UTC.
I dropped the second point on Lacrosse 5 as it probably does not represent the position at the end of the exposure, but rather the point where it became too faint for the camera. The first points suggest it was perhaps some 0.15s late and on-track.
Lacrosse 4 was perhaps some 0.2s late (delta T's vary a bit between 0.05s and 0.30s) and somewhat off-track (about 0.05 degree).
I obtained two images (hence 4 positions) on Lacrosse 4, the first one of which captured the sat cruising at a steady mag. +3 close to the Pleiades cluster (image below):
(click image to enlarge)
A minute earlier I had captured Lacrosse 5 in the act of doing its infamous "disappearance trick" again. The image below shows it fading rapidly, in fact the apparent trail end on the image predates the end of the exposure. Visually, I timed the disappearance at about 18:25:30 (+/- 2s) UTC.
(click image to enlarge)
I dropped the second point on Lacrosse 5 as it probably does not represent the position at the end of the exposure, but rather the point where it became too faint for the camera. The first points suggest it was perhaps some 0.15s late and on-track.
Lacrosse 4 was perhaps some 0.2s late (delta T's vary a bit between 0.05s and 0.30s) and somewhat off-track (about 0.05 degree).
Sunday, 21 January 2007
Its flaring time again...! (updated)
Drifting fields of clouds made observing a gamble this evening. In between the cloud fields however, it was marvellously clear again.
I had the fortune to observe and photograph another very nice flare of Lacrosse 4 (00-047A, #26473), again just before eclipse entry. It briefly flared to mag. 0 at 19:29:41 +/- 2s UTC, near the Andromeda-Pegasus border. The decline in brightness after the flare was very rapid, unlike the rise to it, perhaps due to the eclipse entry (predicted for 19:29:53 UTC).
I lost the first pass of Lacrosse 5 (05-016A, #28646) at 17:35 UTC to an untimely pass of a field of clouds (3 minutes after the pass, it was completely clear again...). The same almost happened to the second pass at 19:19 UTC. I did capture it on one image through a hole in the cloud cover though (see below). In fact the second image shows it too, through the cloud cover...but is useless of course for position determinations.
Update: Like yesterday, 00-047A was 0.8s late, 0.05 degree off-track.
05-016A was exactly on-time and on-track: it doesn't happen every day that you get such results:
STAT__YYday HH:MM:SS.sss___XTRK____deltaT___Perr
4353__07 21 19:18:36.100___0.00____0.00_____0.003
4353__07 21 19:18:46.800__-0.00____0.00_____0.005
I had the fortune to observe and photograph another very nice flare of Lacrosse 4 (00-047A, #26473), again just before eclipse entry. It briefly flared to mag. 0 at 19:29:41 +/- 2s UTC, near the Andromeda-Pegasus border. The decline in brightness after the flare was very rapid, unlike the rise to it, perhaps due to the eclipse entry (predicted for 19:29:53 UTC).
(click image to enlarge)
I lost the first pass of Lacrosse 5 (05-016A, #28646) at 17:35 UTC to an untimely pass of a field of clouds (3 minutes after the pass, it was completely clear again...). The same almost happened to the second pass at 19:19 UTC. I did capture it on one image through a hole in the cloud cover though (see below). In fact the second image shows it too, through the cloud cover...but is useless of course for position determinations.
(click image to enlarge)
note: times should read 19:18:36.1 -19:18:46.8 UTC
note: times should read 19:18:36.1 -19:18:46.8 UTC
Update: Like yesterday, 00-047A was 0.8s late, 0.05 degree off-track.
05-016A was exactly on-time and on-track: it doesn't happen every day that you get such results:
STAT__YYday HH:MM:SS.sss___XTRK____deltaT___Perr
4353__07 21 19:18:36.100___0.00____0.00_____0.003
4353__07 21 19:18:46.800__-0.00____0.00_____0.005
Saturday, 20 January 2007
A Lacrosse 4 flare, and a Lacrosse 5 "disappearance trick"
This evening was a very clear evening. The storms of the past days (there was another one last night, and there is yet another one predicted for tonight) have blown the atmosphere very transparent. It was a bit windy and chilly, but observing conditions were perfect otherwise.
Highlight of the evening was a fine short and bright magnitude +0.5 flare by Lacrosse 4 (00-047A, # 26473) at 18:53:00 +/- 1s UTC, just before it entered into eclipse in Taurus.
Earlier that evening, Lacrosse 5 (05-016A, #28646) did the opposite: it did its "disappearance trick" again at 18:31:27 +/- 2 s UTC, some 1.5 minutes before eclipse entry. The camera was open while it happened: the first of below two pictures, where it is already much fainter than before and disappears. The second picture below was taken a minute before the first, and shows just how bright Lacrosse 5 was at that time (about mag. +1.5).
After it disappeared, it did not re-appear visually (naked eye) or photographically.
Update: Lacrosse 4 (00-047A) was about 0.8s late relative to a two week old elset. Lacrosse 5 was on-time.
After image enhancement in Photoshop, the third image does show Lacrosse 5 as well, but barely. It must have been mag. +4 or fainter.
Bruce MacDonald from the UK reports he observed Lacrosse 5 "disappearing"as well on seesat.
(click image to enlarge)
Highlight of the evening was a fine short and bright magnitude +0.5 flare by Lacrosse 4 (00-047A, # 26473) at 18:53:00 +/- 1s UTC, just before it entered into eclipse in Taurus.
Earlier that evening, Lacrosse 5 (05-016A, #28646) did the opposite: it did its "disappearance trick" again at 18:31:27 +/- 2 s UTC, some 1.5 minutes before eclipse entry. The camera was open while it happened: the first of below two pictures, where it is already much fainter than before and disappears. The second picture below was taken a minute before the first, and shows just how bright Lacrosse 5 was at that time (about mag. +1.5).
After it disappeared, it did not re-appear visually (naked eye) or photographically.
Update: Lacrosse 4 (00-047A) was about 0.8s late relative to a two week old elset. Lacrosse 5 was on-time.
After image enhancement in Photoshop, the third image does show Lacrosse 5 as well, but barely. It must have been mag. +4 or fainter.
Bruce MacDonald from the UK reports he observed Lacrosse 5 "disappearing"as well on seesat.
(click images to enlarge)
Friday, 19 January 2007
Storm over Cospar 4353
A Gale-force storm has been raging in our country yesterday, killing 6 people and bringing all train traffic to a halt. At 11:03 am the first roofing tiles came down here at Cospar 4353. The peak in wind-force was at about 7-8 pm. In Zeeland province, wind speeds of 133 km/h were recorded.
The closest distance to the center of the storm depression for Cospar 4353 was at about 15:30 CET (14:30 UTC), as can be deduced from the above barogram obtained by my courtyard weather-station.
The sky was clear during twilight, but this was also the peak of the storm. A roofing tile had already come down some 2.5 yards from where I normally put my tripod, so I did not dare to risk my head and camera to other plunging roofing tiles. Moreover, the tripod would have blown over I think.
Monday, 15 January 2007
Again Lacrosse 5, and a comet observation in daylight!
A poor evening after a nice day. Alas, late in the afternoon and in the early evening cirrus moved in. This after it had been nice and clear blue skies earlier, allowing a rare view of a daylight comet!
At 14:35 local time (CET) during the clear part of the day, I managed (with difficulty, but certainty) to observe comet C/2006 P1 McNaught with the unaided naked eye in daylight, close to the sun! It was a tiny smudge at a 7-8 o' clock position relative to the sun. Not easy, but once located unmistakable. The sun was covered from direct vision.
Due to the cirrus that came in later today, Lacrosse 5 (05-016A) was the only one of three sats (Lacrosse 2, Lacrosse 5 and USA 193) I tried this evening that was captured. The first point on Lacrosse 5 might be a bit iffy, the second is good I think. delta T is similar to yesterday (+0.2s).
Shortly after this exposure, Lacrosse 5 "disappeared" again. This happened between 17:56:00 and 17:56:30 UTC (I did not see it disappear as I was handling the camera, but when I looked up again after triggering the 2nd image it was gone visually, and it is not visible on the 2nd image either).
At 14:35 local time (CET) during the clear part of the day, I managed (with difficulty, but certainty) to observe comet C/2006 P1 McNaught with the unaided naked eye in daylight, close to the sun! It was a tiny smudge at a 7-8 o' clock position relative to the sun. Not easy, but once located unmistakable. The sun was covered from direct vision.
Due to the cirrus that came in later today, Lacrosse 5 (05-016A) was the only one of three sats (Lacrosse 2, Lacrosse 5 and USA 193) I tried this evening that was captured. The first point on Lacrosse 5 might be a bit iffy, the second is good I think. delta T is similar to yesterday (+0.2s).
Shortly after this exposure, Lacrosse 5 "disappeared" again. This happened between 17:56:00 and 17:56:30 UTC (I did not see it disappear as I was handling the camera, but when I looked up again after triggering the 2nd image it was gone visually, and it is not visible on the 2nd image either).
Sunday, 14 January 2007
Failed Lacrosse flare
Phillip Masding predicted a potential flare by Lacrosse 5 (05-016A, #28646) for my location for 17:06:59 UTC this evening. This was to be in late twilight, and at a favourable sky elevation of 70 degrees (almost in the zenith).
Streaks of cirrus occupied the sky at that time. About 1 minute before Lacrosse 5, I observed Lacrosse 2 (91-017A, #21147) pass through the zenith at a bright mag. +2. A minute later Lacrosse 5 however turned out to be very faint, mag. +3.5 or fainter. It did not flare, and the trail on the photographic image is very marginal. I only used one position of it, as the other one came out as an obvious anomaly.
Lacrosse 2 is visible in the same image, but in a streak of cirrus, and hence very marginal. I did not get usable positions on it.
During the next pass of Lacrosse 5, at 18:50 UTC and 48 degree maximum sky elevation due North, it was brighter (about mag. +2.5) . It easily registered on the photographic image (see below), and added two positions.
The three positions obtained on Lacrosse 5 in total suggest it was on-track, and about 0.2s late relative to a 4-day-old elset.
Streaks of cirrus occupied the sky at that time. About 1 minute before Lacrosse 5, I observed Lacrosse 2 (91-017A, #21147) pass through the zenith at a bright mag. +2. A minute later Lacrosse 5 however turned out to be very faint, mag. +3.5 or fainter. It did not flare, and the trail on the photographic image is very marginal. I only used one position of it, as the other one came out as an obvious anomaly.
Lacrosse 2 is visible in the same image, but in a streak of cirrus, and hence very marginal. I did not get usable positions on it.
During the next pass of Lacrosse 5, at 18:50 UTC and 48 degree maximum sky elevation due North, it was brighter (about mag. +2.5) . It easily registered on the photographic image (see below), and added two positions.
The three positions obtained on Lacrosse 5 in total suggest it was on-track, and about 0.2s late relative to a 4-day-old elset.
(click image to enlarge)
Thursday, 11 January 2007
Lacrosse 5 flare, and comet C/2006 P1 McNaught
The weather persistently has been very bad since 1 January. Today was the first day I have seen a satellite again.
This evening I observed Lacrosse 5 (05-016A) in a clear sky and saw it briefly flare from mag. +2 to mag. +0.5 during about 2-3 seconds at 18:08:27 ± 5 s UTC.
But allas I have no positions to report. When the camera tried to write the first image to the CF card, a writing error occurred and the image data got corrupted. I had to restart the camera, made a mistake in the settings (forgot the 10 second self-timer), so lost a second imaging opportunity, and then the sat disappeared behind the roof.
Al this while it was very windy. An hour earlier, windforce shortly reached storm values.
Earlier this evening (from another location), during this stormy phase, I caught a glimpse of comet C/2006 P1 McNaught, in deep twilight a few degrees above the horizon. Not very spectacular under these conditions but at least I have seen it. I even could see a short tail by the naked eye.
This evening I observed Lacrosse 5 (05-016A) in a clear sky and saw it briefly flare from mag. +2 to mag. +0.5 during about 2-3 seconds at 18:08:27 ± 5 s UTC.
But allas I have no positions to report. When the camera tried to write the first image to the CF card, a writing error occurred and the image data got corrupted. I had to restart the camera, made a mistake in the settings (forgot the 10 second self-timer), so lost a second imaging opportunity, and then the sat disappeared behind the roof.
Al this while it was very windy. An hour earlier, windforce shortly reached storm values.
Earlier this evening (from another location), during this stormy phase, I caught a glimpse of comet C/2006 P1 McNaught, in deep twilight a few degrees above the horizon. Not very spectacular under these conditions but at least I have seen it. I even could see a short tail by the naked eye.
Monday, 1 January 2007
A good start of the new year!
The first evening of 2007 was very clear. Hopefully this sets the trend for 2007!
It was quite windy, and observations were done in twilight and with a near-full moon above the horizon. As a result, the images are quite fogged out.
Targets were Lacrosse 3 (97-064A, #25017) and the International Space Station (see image below)
97-064A did not show up well on the images: faint trails which almost drowned in the background fog. It was about mag. +3. I dropped one point from the second image obtained, as it was obviously in error. Hence 3 positions were left. 97-064A was some 0.5s late relative to a 3 day old elset.
ISS (98-067A) made a nice pass culminating at 40 degrees elevation. I picked it up low in the west, it was mag. -1 throughout the pass (I could not see its low eastern trajectory part though). Around culmination and after it it was a bit orange again. Positions were obtained for calibration purposes. Below is the first of the two images of ISS I took: it is still low in the West here:
It was quite windy, and observations were done in twilight and with a near-full moon above the horizon. As a result, the images are quite fogged out.
Targets were Lacrosse 3 (97-064A, #25017) and the International Space Station (see image below)
97-064A did not show up well on the images: faint trails which almost drowned in the background fog. It was about mag. +3. I dropped one point from the second image obtained, as it was obviously in error. Hence 3 positions were left. 97-064A was some 0.5s late relative to a 3 day old elset.
ISS (98-067A) made a nice pass culminating at 40 degrees elevation. I picked it up low in the west, it was mag. -1 throughout the pass (I could not see its low eastern trajectory part though). Around culmination and after it it was a bit orange again. Positions were obtained for calibration purposes. Below is the first of the two images of ISS I took: it is still low in the West here:
(click image to enlarge)
Sunday, 24 December 2006
Lacrosse 3 & Lacrosse 5 Rk in hazy skies
A late report on observations from December 18. The grant committee hearing last Thursday took too much of my time and energy to report earlier to this log.
This were the first observations being back on-line and tracking with a new laptop ("Elvis") after a fatal crash of my old laptop ("HAL") the 12th. Conditions were poor: hazy. No pretty pictures this time...
I observed Lacrosse 3 and the Lacrosse 5 Rocket (05-016B). The Lacrosse 3 (97-064A) was trail very marginal on the image. I dropped a second trail image on 97-064A obtained during its next pass as it was even more marginal. My two points on the first trail come out a few tenths of seconds different from those of other observations around this time.
By contrast, the Lacrosse 5 Rocket (05-016B) trail was of good quality and agreed well with other observations obtained around that time. 05-016B was 4.6s early and 0.11 degrees off-track with regard to an 8 day old elset; 97-064A some 0.9s early and on-track with regard to similar aged elset.
A female neighbour came by for a chat when seeing me photograph and watched 05-016B passing over Polaris with me.
This were the first observations being back on-line and tracking with a new laptop ("Elvis") after a fatal crash of my old laptop ("HAL") the 12th. Conditions were poor: hazy. No pretty pictures this time...
I observed Lacrosse 3 and the Lacrosse 5 Rocket (05-016B). The Lacrosse 3 (97-064A) was trail very marginal on the image. I dropped a second trail image on 97-064A obtained during its next pass as it was even more marginal. My two points on the first trail come out a few tenths of seconds different from those of other observations around this time.
By contrast, the Lacrosse 5 Rocket (05-016B) trail was of good quality and agreed well with other observations obtained around that time. 05-016B was 4.6s early and 0.11 degrees off-track with regard to an 8 day old elset; 97-064A some 0.9s early and on-track with regard to similar aged elset.
A female neighbour came by for a chat when seeing me photograph and watched 05-016B passing over Polaris with me.
Friday, 15 December 2006
SatTrackCam temporarily down
SatTrackCam has been temporarily down the past week and will be for a few more days. The reason is that my old faithful lap-top HAL died last Tuesday.
I have a new lap-top since late this afternoon. I need a few more days however to configure it, re-install software etcetera. Moreover, I have to be at a committee hearing of our National Science Foundation coming Friday in connection to my Post-Doc proposal and have to prepare for that. So I think it will not be before Christmas before I am fully up and running again.
I have a new lap-top since late this afternoon. I need a few more days however to configure it, re-install software etcetera. Moreover, I have to be at a committee hearing of our National Science Foundation coming Friday in connection to my Post-Doc proposal and have to prepare for that. So I think it will not be before Christmas before I am fully up and running again.
Sunday, 10 December 2006
Lacrosse 2 & Lacrosse 5 Rocket in hazy skies
Unlike the clear skies of this morning (see previous post), it was quite hazy this evening. Images were considerably fogged as a result - no pretty pictures.
Targets were Lacrosse 2 (91-017A, #211147) and the Lacrosse 5 Rocket stage (05-016b, #28647). Got two images on each object. The trail of 91-017A on the first image was very marginal. 05-016B was nice and bright, I saw it go into eclips near the end of the last exposure. Both objects crossed Pegasus and then Andromeda/Aries, 20 minutes apart in time.
05-016B was some 6.4 to 6.5s early and some 0.15 degree off-track relative to 6 day old elset 06339.03434948. 91-017A was nicely on-time and on-track.
Targets were Lacrosse 2 (91-017A, #211147) and the Lacrosse 5 Rocket stage (05-016b, #28647). Got two images on each object. The trail of 91-017A on the first image was very marginal. 05-016B was nice and bright, I saw it go into eclips near the end of the last exposure. Both objects crossed Pegasus and then Andromeda/Aries, 20 minutes apart in time.
05-016B was some 6.4 to 6.5s early and some 0.15 degree off-track relative to 6 day old elset 06339.03434948. 91-017A was nicely on-time and on-track.
Lacrosse 5 & its "disappearance trick" again
I observed Lacrosse 5 (05-016A, 28646) this morning, and timed it's "disappearing trick" again.
I saw it emerge out of earth shadow above alpha Auriga at a bright mag. +1 at about 5:19:00 UTC. It then crossed towards Umi, over Polaris, bright and steady. At 5:21:24 ± 1s UTC at 45 deg altitude in the N-NE it did its trick again, fading from mag. +1.5 to naked eye invisibility in just a few seconds.
05-016A was nicely on-time and on-track. I obtained 3 images, hence 6 positions.
I was up in the middle of the night too, to watch the Shuttle launch on NASA-TV at 2:47 am local time.
I saw it emerge out of earth shadow above alpha Auriga at a bright mag. +1 at about 5:19:00 UTC. It then crossed towards Umi, over Polaris, bright and steady. At 5:21:24 ± 1s UTC at 45 deg altitude in the N-NE it did its trick again, fading from mag. +1.5 to naked eye invisibility in just a few seconds.
05-016A was nicely on-time and on-track. I obtained 3 images, hence 6 positions.
I was up in the middle of the night too, to watch the Shuttle launch on NASA-TV at 2:47 am local time.
(click image to enlarge)
Thursday, 7 December 2006
Shuttle STS-116
Pre-flight orbital elements for the upcoming Space Shuttle Discovery STS-116 flight came available on the NASA Spaceflight website yesterday.
A quick check yesterday evening revealed to me that, alas, the flight will not be visible for me: all night-time passes (before docking and after undocking) will take place while the Shuttle is in eclipse. So, 'll have to be content with just watching the launch on NASA-TV.
A quick check yesterday evening revealed to me that, alas, the flight will not be visible for me: all night-time passes (before docking and after undocking) will take place while the Shuttle is in eclipse. So, 'll have to be content with just watching the launch on NASA-TV.
Wednesday, 29 November 2006
UARS impostering as ISS, the real ISS, Lacrosses and a rocket stage
This morning was very fine. I obtained 15 positions on 5 objects: Lacrosse 2 (91-017A), Lacrosse 3 (97-064A), UARS (91-063B), an old Russian Soyuz rocket stage (70-037B), and the International Space Station, which made a fine pass again.
And I almost got fooled by a celestial imposter!
At the end of the fine pre-dawn session I was waiting for a pass of the ISS. While preparing the camera I realised I had used elements from before the scheduled orbit boost for ISS, so I reckoned it might perhaps appear somewhat off-time (later, it turned out I made a mistake in this anyway, as the boost would only occur his evening and not last evening as I thought by mistake...).
At 5:42 UTC, 1 minute early, I saw a bright object appear in Gemini close to but slightly south of the point where ISS should emerge from earth shadow. It initially was about mag. +0.5 in brightness. "Ah, there it is!" I thought and triggered the camera...
As the camera ended its exposure, I realized something was wrong...
My brain registered disappointment about the brightness of this "ISS", then wondered about a 1 minute early appearance (a bit too much??), and as I watched the object I realized its course was bringing it much too much north to be ISS...so, this was an imposter!
So I quickly swapped back the camera. And yes, there it appeared,low west, almost at te moment I turned my sight to it: the real ISS, close to Castor and Pollux, at a splendid bright mag. -3...!
The "imposter" was later identified as te Upper atmospheric research satellite UARS (91-063B, #21701). The darn thing almost fooled me...! :-P
Like from my images of last Friday, I constructed a mozaic of two ISS trail images from this morning again:
It is well visible how bright ISS is just after coming out of earth shadow.
Apart from ISS and UARS, I also imaged Lacrosses 2 & 3 this morning, and recorded a second stray on one of the Lacrosse 2 images, which turned out to be 70-037B (#04394), an old Russian Soyuz rocket stage from the Meteor 1-4 launch, 1970.
And I almost got fooled by a celestial imposter!
At the end of the fine pre-dawn session I was waiting for a pass of the ISS. While preparing the camera I realised I had used elements from before the scheduled orbit boost for ISS, so I reckoned it might perhaps appear somewhat off-time (later, it turned out I made a mistake in this anyway, as the boost would only occur his evening and not last evening as I thought by mistake...).
At 5:42 UTC, 1 minute early, I saw a bright object appear in Gemini close to but slightly south of the point where ISS should emerge from earth shadow. It initially was about mag. +0.5 in brightness. "Ah, there it is!" I thought and triggered the camera...
(click image to enlarge)
As the camera ended its exposure, I realized something was wrong...
My brain registered disappointment about the brightness of this "ISS", then wondered about a 1 minute early appearance (a bit too much??), and as I watched the object I realized its course was bringing it much too much north to be ISS...so, this was an imposter!
So I quickly swapped back the camera. And yes, there it appeared,low west, almost at te moment I turned my sight to it: the real ISS, close to Castor and Pollux, at a splendid bright mag. -3...!
(click image to enlarge)
The "imposter" was later identified as te Upper atmospheric research satellite UARS (91-063B, #21701). The darn thing almost fooled me...! :-P
Like from my images of last Friday, I constructed a mozaic of two ISS trail images from this morning again:
(click image to enlarge)
It is well visible how bright ISS is just after coming out of earth shadow.
Apart from ISS and UARS, I also imaged Lacrosses 2 & 3 this morning, and recorded a second stray on one of the Lacrosse 2 images, which turned out to be 70-037B (#04394), an old Russian Soyuz rocket stage from the Meteor 1-4 launch, 1970.
Tuesday, 28 November 2006
Satellites, ISS and an Asteroid
This morning was another clear and still morning. A bit of haze and a small patch of thin clouds every now and then. Like the previous morning, I observed Lacrosse 2 & 3 (91-017A & 97-064A) and a zenith pass of the International Space Station. I obtained 2 images and thus 4 points on each object.
97-064A and 91-017A (Lacrosses 3 & 2) appeared some 10 minutes after each other in the same sky area with almost the same sky elevations, range and illumination phase. This made me appreciate the somewhat different intrinsic brightness between the two (Lacrosse 3 seems a bit fainter), which was clear visually and to some extend also on the photographs.
ISS was nice and bright at about mag. -2 when emerging out of shadow crossing the legs of Ursa Major near the zenith (see image below), yet not as bright as last Friday.
Meanwhile, todays' DOU in MPEC 2006-W103 contained the publication of my latest asteroid discovery, 2002 BF32 (packed: K02B32F). It is a 1 km large (H17.6) MB II main belt asteroid which I discovered in NEAT archive images from January 2002 last week. It has perihelion at 2.1 A, aphelion at 3.1 AU and an orbital inclination of 12 degrees. The orbital arc is short, I managed to track it over only 3 nights.
97-064A and 91-017A (Lacrosses 3 & 2) appeared some 10 minutes after each other in the same sky area with almost the same sky elevations, range and illumination phase. This made me appreciate the somewhat different intrinsic brightness between the two (Lacrosse 3 seems a bit fainter), which was clear visually and to some extend also on the photographs.
(click image to enlarge)
ISS was nice and bright at about mag. -2 when emerging out of shadow crossing the legs of Ursa Major near the zenith (see image below), yet not as bright as last Friday.
Meanwhile, todays' DOU in MPEC 2006-W103 contained the publication of my latest asteroid discovery, 2002 BF32 (packed: K02B32F). It is a 1 km large (H17.6) MB II main belt asteroid which I discovered in NEAT archive images from January 2002 last week. It has perihelion at 2.1 A, aphelion at 3.1 AU and an orbital inclination of 12 degrees. The orbital arc is short, I managed to track it over only 3 nights.
(click image to enlarge)
Monday, 27 November 2006
Lacrosses and ISS
Another clear morning, albeit slightly hazy. Targets were Lacrosse 2 (91-017A, #21147), Lacrosse 3 (97-064A, #25017) and the International Space Station.
The ISS was less bright than last Friday, at about mag. -1.5 shortly after exiting shadow in Canes Venatici. It was "white" this time. The positional residues are nice:
STA___YYday_HH:MM:SS.sss___XTRK____deltaT____Perr
4353__06331_05:04:31.100__-0.00_____0.09_____0.054
4353__06331_05:04:41.800___0.00_____0.01_____0.008
Lacrosse 2 (91-017A) was bright (mag. +2) as it came out of shadow and traversed the tail of Ursa Major. I obtaned 1 picture, 2 points. It was 0.4s late and 0.2 degrees off-track relative to an 8-day old elset.
Lacrosse 3 (97-064A) was fainter (mag. +3.0 to +3.5). I obtained 2 images, hence 4 points. was 1 second late but on-track relative to an 8-day-old elset.
The ISS was less bright than last Friday, at about mag. -1.5 shortly after exiting shadow in Canes Venatici. It was "white" this time. The positional residues are nice:
STA___YYday_HH:MM:SS.sss___XTRK____deltaT____Perr
4353__06331_05:04:31.100__-0.00_____0.09_____0.054
4353__06331_05:04:41.800___0.00_____0.01_____0.008
Lacrosse 2 (91-017A) was bright (mag. +2) as it came out of shadow and traversed the tail of Ursa Major. I obtaned 1 picture, 2 points. It was 0.4s late and 0.2 degrees off-track relative to an 8-day old elset.
Lacrosse 3 (97-064A) was fainter (mag. +3.0 to +3.5). I obtained 2 images, hence 4 points. was 1 second late but on-track relative to an 8-day-old elset.
(Click images to enlarge)
Friday, 24 November 2006
A Lacrosse, a Lacrosse rocket and the ISS (updated)
(Click images to enlarge)
I was up early this morning. The sky had cleared, although streaks of fast-moving clouds still wandered across the sky.
First target was Lacrosse 3 (97-064A,# 25017) around 5:17 local time (4:17 UTC). It was faint, the trail on the photograph was rather marginal. My results suggest it was 0.15 seconds late and 0.1 degree off-track relative to a 5-day old elset, but as the trail was very marginal, don't pin me down on it.
Next target was the Lacrosse 5 Rk rocket stage (05-016B, #28647). While traversing from Auriga into Gemini around 5:57 local time it was quite bright, magnitude +1. Once in Leo at 5:58 local time, it had faded to mag +3.5. Got 2 photographs and hence 4 positions, but the last one dropped because it came out clearly erratic. The other three points more or less agree, and suggest it was on-time and on-track.
Highlight of the night was a fine pass of the International Space Station at 6:37 local time (5:37 UTC), see the two pictures above. When it came into view at about 35 degrees altitude, close to Procyon, it already was well into the negative magnitudes, about magnitude -3 I estimate. It stayed that bright while crossing the body of Leo and passing close to Saturn at about 55 degrees altitude: it dimmed when going towards the eastern horizon. It had a somewhat orange colour again.
I have seen ISS this bright before, but that was during zenith passes. I wonder what brightness it currently could attain in the zenith. Hope to be able to check that out soon, as ISS starts to make more favourable morning passes.
UPDATE: I've combined the two ISS pass photographs into one composite image
(click image to enlarge)
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