Orwell Astronomical Society (Ipswich)
All-Sky Images, 23 June 2018 - 12 August 2024
In 1978, OASI member Alan Smith started running an all-sky camera. Unfortunately, a combination of slow optics and increasing levels of light pollution meant that, by 1986, the camera was producing few good results and Alan ceased operations.
Fast-forward 32 years to 2018 and imaging technology had made huge strides: chemical film was a distant memory, imaging was all-electronic and sensitivities were vastly superior to those possible with the earlier equipment. Alan reprised the all-sky camera using modern technology. Later, James Appleton and Martin Richmond-Hardy also began running all-sky cameras. Capturing images from different locations enabled triangulation of meteor trails to estimate the trajectories of the bodies. (The methodology used for triangulation is that of [1] as implemented in [2], with some modifications.)
Unfortunately, both Martin and Alan passed away in 2023.
A selection of images from the cameras is below. The cameras.
Details
Images
James. 01:55:55 - 01:56:25 UT, single 30 exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
James. 01:08:52 - 01:09:22 UT, single 30 exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 120, colour.
James. 23:13:25 - 23:18:58 UT, eleven consecutive 30 exposures. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 120, colour.
James. 21:41:49 - 21:42:19 UT, single 30 exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 120, colour.
Alan. Circa21:00, stack of thirty-six 40 s exposures. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter.
An auroral display visible over the UK in late February 2023 caught most observers completely unprepared! The display occurred on the nights of 26 and 27 February, and was by far the more intense on the first night, being visible from as far south as Devon.
Alan. 21:21:45 - 21:34:17 UT, stack of eighteen 40 s exposures. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter.
Alan. 00:01:09 - 00:01:49 UT, single 40 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter.
Several cameras captured the event, and UKMON performed an analysis of the observations, concluding that the body was likely a very small asteroid from the main belt, with a mass of 23 kg. The track began at 1.33°W, 51.51°N at an altitude of 93 km and descended steeply, at 68° to the horizontal, finishing some 12 km later at 1.16°W, 51.49°N at al altitude of 63 km. There were various estimates of magnitude; one of the most credible was that the first flare was of magnitude circa -11 and the seond circa -8.5.
Top: Alan. 23:25:12 - 23:25:52 UT, single 40 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter, 16 BPS 50/50 open/close.
Middle: James. 23:25:29 - 23:25:59 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Bottom: estimate of the meteor trajectory by triangulating the observations. The object travelled on a path above Basildon to Chelmsford, descending from an altitude of 112 km to 73 km.
Alan. 20:10:46 - 20:11:26 UT, single 40 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter.
Top: Alan. 23:28:38 - 23:30:18 UT, single 40 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter, 16 BPS 50/50 open/close.
Middle: James. 23:29:46 - 23:30:16 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Bottom: estimate of the meteor trajectory by triangulating the observations. The object travelled on a descending path heading north-west over Essex.
Alan. 22:11:25 - 22:12:05 UT, single 40 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 250, colour, rotating shutter.
Although the Perseids meteor shower peaks around 12 August each year, the 2022 display was disappointing. However, around the time of the peak, several sporadic meteors were observed, of which this is one.
Top: Alan. 02:39:20 - 02:40:20 UT, single 60 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter, 16 BPS 50/50 open/close.
Middle: James. 02:39:24 - 02:40:24 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Bottom: estimate of the meteor trajectory by triangulating the observations. The object travelled on a descending path heading north-east over the English Channel towards the Isle of Wight.
Top: Alan. 22:18:01 - 22:19:01 UT, single 60 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter, 16 BPS 50/50 open/close.
Middle: James. 22:18:15 - 22:18:45 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Bottom: estimate of the meteor trajectory by triangulating the observations. The object appeared at an altitude of 146 km over Southampton and descended on a north-easterly trajectory, becoming invisible (entering dark flight) at an altitude of 68 km over Slough.
Top: Alan. 02:54:50 - 02:55:50 UT, single 60 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter, 16 BPS 50/50 open/close.
Middle: James. 02:55:00 - 02:55:30 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Bottom: montage of James's images showing the evolution of the trail over the period 02:55:00 - 02:59:34 UT. Times are end times of images in UT. All images except the first have been significantly contrast-stretched to make the trail visible.
The meteor was also imaged by IMO observers, and logged as event 2028-2022. The IMO triangulated the trajectory, which placed the trail above the town of Achen, Germany, some 370 km distant.
Top: Alan. 02:26:54 - 02:27:54 UT, single 60 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter, 16 BPS 50/50 open/close.
Middle: James. 02:27:18 - 02:27:48 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Bottom: estimate of the meteor trajectory by triangulating the observations. The object became visible at an altitude of 92 km over the North Sea, 34 km due east of Thorpeness on the coast of Suffolk. It then travelled south-west descending, until, at an altitude of 57 km, it entered dark flight.
Top: Alan. 22:20:58 - 22:21:58 UT, single 60 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter, 16 BPS 50/50 open/close.
Middle: James. 22:20:37 - 22:21:07 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Bottom: estimate of the meteor trajectory by triangulating the observations. The object appeared at an altitude of 76 km over the North Sea and descended on a trajectory towards the Netherlands, becoming invisible (entering dark flight) at an altitude of 46 km.
The images of the meteor have been contrast-enhanced to make the faint initial segment of the trail visible.
Top: Alan. 05:55:29 - 05:59:37 UT, stack of four 60 s exposures. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter, 16 BPS 50/50 open/close.
Bottom: James. 05:55:47 - 05:59:49 UT, stack of eight 30 s exposures. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
The images have been contrast-boosted to make the satellite trails more obvious.
Top: Martin. 02:11:39 - 02:11:44 UT, video from UKMON 56 camera.
Middle: stack of video frames as above.
Bottom: Alan. 02:10:56 - 02:11:56 UT, single 60 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter, 16 BPS 50/50 open/close.
Top: Alan. 05:42:44 - 05:43:44 UT, single 60 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter, 16 BPS 50/50 open/close.
Next: James. 05:43:01 - 05:43:31 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Next: montage of Alan's images showing formation and gradual dispersion of cloud of material ejected by the bolide. Images are 60 s duration; times are start of image.
Next: corresponding montage of James's images. Images are 30 s duration; times are end of image. Two distinct pieces of ejecta from the bolide are marked by arrows.
Bottom: estimate of the meteor trajectory by triangulating the observations. The object appeared at an altitude of 118 km over the North Sea off Essex and descended on a trajectory parallel to the coast, becoming invisible (entering dark flight) at an altitude of 77 km.
Top: Alan. 02:08:37 - 02:09:37 UT, single 60 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter, 16 BPS 50/50 open/close.
Middle: James. 02:09:03 - 02:09:33 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Bottom: estimate of the meteor trajectory by triangulating the observations. The object became visible at an altitude of 124 km off the French west coast at Fort-Mahon-Plage and travelled due north, descending, until it reached an altitude of 31 km over Dover, where it entered dark flight.
Top: Alan. 01:04:21 - 01:05:21 UT, single 60 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 250, colour, rotating shutter, 16 BPS 50/50 open/close.
Next: James. 01:04:27 - 01:04:57 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Next: Martin. 01:04:47 - 01:04:49 UT, single 2.5 s exposure. ZWO ASI 120MM with 1.55 mm fisheye lens, B&W.
Bottom: estimate of the meteor trajectory by triangulating the observations (there were too few stars visible in Martin's image to enable triangulation). The object became visible at an altitude of 93 km and descended over Bury St. Edmunds, producing a terminal flare at an altitude of 51 km.
Alan. 22:08:06 - 22:09:06 UT, single 60 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter.
Members of UKMON calculated the trajectory as follows. The meteor, weighing about 11 g, entered the atmosphere over Thetford at an altitude of about 107 km travelling at around 31 km/s. Its short, steep flight ended its visible phase above Kings Lynn at about 59 km altitude. It reached a maximum visible magnitude of about -5.8. The object is unlikely to have survived passage through the atmosphere. The all-sky image shows the bright trail with around 30 breaks caused by the rotating shutter (producing 16 breaks/second), giving a visible flight of about 2 s, ending with a small terminal flare. Zooming-in to the image shows at least one glowing ember continuing beyond the flare event! A radio meteor detector in Ipswich picked up a faint echo of the Brams transmitter (in Dourbes, Belgium) via ionisation of the trail. Unfortunately, no other OASI-operated cameras captured the event.
Top: Alan. 00:17:06 - 00:18:06 UT, single 60 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter, 16 BPS 50/50 open/close.
Middle: James. 21:18:59 - 21:19:29 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Bottom: estimate of the meteor trajectory by triangulating the observations. The object became visible at an altitude of 117 km south-east of London, travelling north-west, and became invisible at an altitude of 85 km.
Top: Alan. 21:18:30 - 21:19:30 UT, single 60 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter, 16 BPS 50/50 open/close.
Middle: James. 21:18:59 - 21:19:29 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Bottom: estimate of the meteor trajectory by triangulating the observations. The object became visible at an altitude of 145 km above Dymchurch in Kent and descended north-west over Ashford, becoming invisible at an altitude of 107 km.
Alan. 21:11:05 - 21:14:05 UT, three consecutive 60 s exposures. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter.
Landsat 9, a joint project by NASA and the US Geological Survey, was launched from Vandenberg Air Base at 18:12 UT on 27 September 2021. The launch vehicle was a Centaur RL10 rocket, the upper stage of which ascended to an altitude of 679 km, released Landsat 9, then manoeuvred to a lower orbit, deployed four CubeSats (two military; two civilian), then finally employed a de-orbit burn to return into the atmosphere for a destructive re-entry over the Pacific Ocean.
The de-orbit burn was also captured by cameras operated by other members of the Dutch Meteor Society.
Alan. 00:31:34 - 00:32:04 UT, single 30 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 250, colour, rotating shutter.
The fireball was also captured by cameras operated by Klaas Jobse (Oostkapelle) and Franky Dubois (Ieper) of the Dutch Meteor Society.
James observed the meteor visually and reported as follows. I was outside and saw the meteor, timing it at 00:32 UT with my wristwatch. The trajectory was on a path from the Square of Pegasus to Orion, below the Moon. I could see some structure, with a bright glow immediately surrounding the bolide, becoming fainter as the radial distance from the bolide increased, and a trail that was bright along the centre of the path and fainter towards the edges. The bolide and trail appeared white. All-in-all, a spectacular sight!
Top: Alan. 01:01:44 - 01:02:14 UT, single 30 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter.
Middle: James. 01:01:41 - 01:02:11 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 160, colour.
Bottom: estimate of the meteor trajectory by triangulating the observations. The object became visible at an altitude of 155 km and descended rapidly with a terminal flare at an altitude of 57 km. The track was west to east a few kilometres north of Cambridge.
Few fireball networks appear to have captured good images of the event. Alan's image shows structure in the terminal flare, including a bright "spike" possibly caused by ejection of material shortly before the object became invisible. Both images, when examined in detail, show structure in the trail possibly indicating a rotating bolide.
Top: Alan. 00:21:24 - 00:21:54 UT, single 30 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter.
Next: Alan. Corresponding single 60 s exposure. Canon 1100D with "LensBaby" 5.8 mm, f3.5 lens (stopped down to f5.6), colour, no liquid crystal shutter.
Next: Martin. 20 s exposure. ZWO ASI120MM camera with ZWO fisheye lens, f1.2, gain 50, B&W. The camera cpatures only the initial part of the trail
Next: James. 00:21:25 - 00:21:55. Single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Bottom: estimate of the meteor trajectory by triangulating the observations. The object became visible at an altitude of 141 km south-east of London, travelling east while descending, and became invisible at an altitude of 108 km.
Alan. 03:38:06 - 03:38:36 UT, single 30 s exposure. ZWO ASI294 camera with 4.5 mm Sigma fisheye lens, f2.8, gain 300, colour, rotating shutter.
Zooming-in shows widely spaced breaks caused by the rotating shutter suggesting a high speed event. The fireball was also captured by cameras of the Dutch Meteor Society.
Alan. 21:37 UT, single 2 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour, no liquid crystal shutter.
Top: Alan. 23:54:52 - 23:55:52 UT, single 60 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour, no liquid crystal shutter.
Bottom: James. 23:54:29 - 23:55:29. Two consecutive 30 s exposures. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Top: Alan. 23:21:52 - 23:26:52 UT, five consecutive 60 s exposures. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour, no liquid crystal shutter.
Bottom: James. 23:21:33 - 23:26:37. Ten consecutive 30 s exposures. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Top: Alan. 22:59:31 - 23:01:31 UT, two consecutive 60 s exposures. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour, no liquid crystal shutter.
Bottom: James. 22:59:16 - 23:02:18. Six consecutive 30 s exposures. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Top: James. The fireball passes between α and β Capricorni. 01:44:01 - 01:44:31 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 160, colour.
Middle: Alan: 01:44:21 - 01:44:28 UT. Video captured by an "eyeball" camera. While travelling through the atmosphere, the ionisation of the fireball and atmosphere produced a radio reflective layer which reflected distant radio transmissions back towards the Earth, enabling them to be received by suitable equipment. Chris Albins in Ipswich monitored reflections from a radio beacon at Dourbes in Belgium (the beacon is primarily used by the Belgian BRAMS network of receivers.) Chris synchronised his recording with Alan's video recording and added it as a sound track. (Note that the time in the the video is BST rather than UT.)
Bottom: trajectory calculated by members of the Dutch Meteor Society. The object entered the atmosphere at an altitude of 96.4 km travelling at about 15.8 km/s to the west of Arras (France). It reached a photometric magnitude of -10.8 (the full moon measures around -12.7) dropping to an altitude of 80.0 km south of Lille (France) before it entered "dark flight" and became invisible.
Top: Alan. 02:49:01 - 02:50:01 UT, single 60 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 400, colour, no liquid crystal shutter.
Second: James. 02:49:16 - 02:49:46 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 130, colour.
Third: Alan. 03:04:59 - 03:05:59 UT, single 60 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 400, colour, no liquid crystal shutter.
Bottom: James. 03:04:58 - 03:05:28 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 130, colour.
Members of the Dutch Meteor Society also observed the meteors, and triangulated the trajectory of the first as follows. The object entered the atmosphere at 112 km altitude at a speed of 48 km/s. It descended through the atmosphere, reaching a peak brightness of magnitude -11.9 and began dark flight at an altitude of 71 km altitude on the Dutch-German border near to Vlodrop.
Top: Alan. 01:18:41 - 01:19:41 UT, single 60 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f4.0, ISO 800, colour, no liquid crystal shutter.
Bottom: James. 01:18:47 - 01:19:02 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Alan. 23:09:32 - 23:10:32 UT, single 60 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f4.0, ISO 800, colour, no liquid crystal shutter.
Observers from the French "FRIPON" network of fisheye video cameras also observed the object, and concluded that its flight was over the English Channel, approximately as follows. It entered the atmosphere at 85 km altitude at a velocity of 29 km/s and with a photometric magnitude of -2.5. Maximum brightness of magnitude -7.5 was at 65 km altitude whilst travelling at around 28 km/s. The object "burned out" and began dark flight at about 45 km altitude travelling at 24 km/s.
Observers from the IMO also logged this event, and calculated a slightly different trajectory, using just eye witness reports.
Top: Alan. 22:25:43 - 22:26:32 UT, single 60 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, no liquid crystal shutter.
Bottom: the fireball was also observed across the Benelux countries. Members of the Dutch Meteor Society reduced the observations to estimate the trajectory of the object. It entered visible flight through the atmosphere at an altitude of about 85 km travelling at about 25 km/s, and entered dark flight, becoming invisible, at an altitude of about 35 km. Its maximum brightness was approximately magnitude -12.5 at an altitude of 48 km. (It was a bright event!)
Top: Alan. 19:37:55 - 19:38:55 UT, single 60 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, no liquid crystal shutter.
Bottom: the fireball was also imaged from Oostkapelle (Netherlands). Using the two images, members of the Dutch Meteor Society reduced the observations to estimate the trajectory of the object. It became visible at an altitude of 74 km and descended at a velocity of 16 km/sec, entering dark flight and becoming invisible at an altitude of 38 km. The maximum photometric magnitude was -5.1, at an altitude of 43 km, so the object was not spectacularly bright. The path of the fireball ran directly between the two observing stations, providing ideal circumstances for triangulation.
Alan. 05:03 - 05:12 UT, stack of nine 60 s exposures. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
James. 06:29:56 - 06:32:28 UT, stack of five 30 s exposures. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Starlink satellites crossing the relevant area of sky around this time were numbers: 1835, 1883, 1944, 1832, 1851, 1882, 1798, 1908, 1893, 1899, 1929 and 1943.
Top: Alan. 17:54:35 - 17:55:35 UT, single 60 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
Bottom: James. 17:54:32 - 17:55:32 UT, stack of two 30 s exposures. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
The many bright dots are likely caused by the object spinning rapidly as a means of providing stabilisation. A close-up of the trail from the two images, shown as an inset in the lower image, shows essentially zero parallax, indicating that the object is at considerable altitude (hundreds of km).
Alan. 20:10:27 - 20:11:27 UT, single 60 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
The liquid crystal shutter chops the image to give an idea of the speed of the object and duration of visibility. The trail shows at least 30 "breaks" indicating a duration of at least three seconds. The image is seriously compromised by the very bright full moon and incoming fog.
Top: Alan. 22:33:36 - 22:34:33 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
Bottom: James. 22:33:13 - 22:33:46 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Top: Alan. 00:48:22 - 00:49:19 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
Bottom: James. 00:49:03 - 00:49:33 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Top: Alan. 05:55:31 - 05:56:28 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
Bottom: James. 05:56:07 - 05:56:37 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Top: Alan. 01:19 - 01:20 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
Bottom: James. 01:20:03 - 01:20:33 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Alan. 04:24:11 - 04:25:08 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
Top: Alan. 01:55:08 - 01:56:05 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
Bottom: James. 01:55:27 - 01:55:57 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
Alan. 03:23 UT, video constructed from 26 exposures of 57 s duration. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
The Leonid meteor shower occurs when the Earth passes through the dust trail created by comet Tempel-Tuttle. Leonid meteors are typically very fast, with an approach velocity of approximately 72 km/s. The video shows a bright flash lasting for about ½ second, leaving a slightly orange/brown ionisation train which drifts slowly up and to the left. The ionisation train is created when atoms of the atmosphere and meteor itself are ripped apart by the tremendous heat generated by friction as the object enters the atmosphere. Winds in the upper atmosphere cause the train to twist and disperse over a period of around 15 minutes. Observation was hampered by light cloud.
Alan. 05:46:51 - 05:47:48 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
Alan. 22:20:40 - 22:21:37 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
The fireball was also imaged by cameras operated by members of the Dutch Meteor Society (DMS) in Oostduinkirke and Ieper. Members of DMS reduced the observations to give the following description of the trajectory: the meteor entered the atmosphere at about 80 km altitude and, after reaching a velocity of around 29 km/s, was seen at about magnitude -4, finally entering the dark phase of flight at about 45 km altitude. The object was a member of the Taurid group of meteors. The green colour of the meteor trail is genuine and probably caused by the ionisation of nickel on the surface of the object.
Top: Alan. 03:39:23 - 03:40:20 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
Bottom: James. 03:40:07 - 03:40:37 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
The object was also observed by members of the Dutch Meteor Society, who reported as follows:
James. 04:06:28 - 04:06:58 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
The night of 24-25 October did not start promisingly, with dense cloud and rain until almost 04:00 UT. However, conditions then improved sufficiently to enable the fireball to be captured. It was also observed by observers in Pleumeur-Bodou (France), Honiton, Manchester and Cardiff. (The apparent dimples in the image are raindrops on the dome of the camera.)
Alan. 19:12 - 19:13 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
Top: Alan. 03:52:48 - 03:54:45 UT, stack of two consecutive 57 s exposures. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
Next: James. 03:53:21 - 03:54:21 UT, stack of two consecutive 30 s exposures. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour.
The object, thought to be approximately one centimetre in diameter, briefly entered the Earth's upper atmosphere and bounced off the lower, denser layers without significantly decelerating. Such behaviour is comparatively rare.
The object was also observed by Benelux observers, one of whom, Hans Betlem, analysed the results and reported as follows:
Next: meteor path, calculated by Hans.
Bottom: height profile, also calculated by Hans.
Top: Alan. 00:25:25 - 00:26:22 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
Bottom: James. 00:25:44 - 00:26:14 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour. An aircraft trail crosses the meteor track.
Top: Alan. 02:20:46 - 02:21:43 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter. Due to cloud, only the terminal flare of the meteor is visible. By way of compensation, the cloud has caused the formation of a lunar halo!
Bottom: James. 02:21:12 - 02:21:42 UT, single 30 s exposure. ZWO ASI 178MC with Fujinon 2.7 mm CF2.7HA-L1 fisheye lens, f1.8, gain 200, colour. In the subsequent frame, starting at 02:21:42 UT, there is a very short track following the terminal flare, before the object began dark flight. The inset shows, L-R, the meteor trail up to the terminal flare, with a blue line indicating the trajectory, the meteor trail after the terminal flare, with a red line indicating the trajectory, and a superposition of the trajectories, showing that they diverge, indicating that the post-flare trail is caused by a small piece of debris ejected at an angle to the original trajectory during the terminal flare. It was fortuitous that the camera transitioned frames immediately after the terminal flare: had it not done so, the post-flare trail would have been lost in the glare of the flare.
Alan. 03:03:53 - 03:04:50 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
James. 01:43:08 - 01:44:29 UT, stack of three consecutive 30 s exposures. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Alan also recorded the object in an image timed 01:43 - 01:44 UT, and recorded a similar pair of widely-spaced tracks in Serpens Cauda on 19 July in a frame timed 22:12 - 22:13 UT.
James. 00:10:24 - 00:10:54 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Alan. 00:39 - 00:40 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
James. 23:29:50 - 23:30:51 UT, stack of two consecutive 30 s exposures. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Alan also imaged the flare: there was minimal parallax between the two images, indicating that the satellite was at an orbital altitude of many hundred km. Zooming into the image reveals traces of a secondary track, although it is largely drowned out by the flare. (See below images taken 23 August 2019 and 15 May 2019.)
Top: Alan. 23:41:34 - 23:42:32 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
Bottom: James. 23:41:09 - 23:42:09 UT, single 60 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 150, colour.
Unfortunately, considerable glare from a gibbous Moon created a very bright sky, with too few stars visible to attempt to triangulate the trajectory of the body from the two images.
Alan. 02:41 - 02:42 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
Alan. 22:29 - 22:30 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
Top: Alan. 02:31:55 - 02:32:53 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour, liquid crystal shutter.
Middle: James. 02:32:24 - 02:32:54 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Bottom: estimate of the meteor track over the English channel and southern England, descending from 88 km to 40 km.
James. 19:37:33 - 19:42:07 UT, stack of ten consecutive 30 s exposures. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Alan. 00:19:27 - 00:20:25 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, colour, liquid crystal shutter.
James. 19:18:27 - 19:19:27 UT, stack of two consecutive 30 s exposures. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
James. 00:22:14 - 00:24:45 UT, stack of five consecutive 30 s exposures. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Top: Alan. 19:34:27 - 19:35:25 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour, liquid crystal shutter. The latter imposed only two breaks in the trail, implying that the object was fast-moving.
Bottom: James. 19:34:17 - 19:34:47 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Cloud and lack of stars visible in the vicinity prevented a triangulation from being carried out.
Top: Alan. 19:59 - 20:00 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour, liquid crystal shutter.
Bottom: James. 19:59:51 - 20:00:51 UT, stack of two consecutive 30 s exposures. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
James. 04:20:20 - 04:22:21 UT, stack of four consecutive 30 s exposures. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Alan. 04:07 - 04:08 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 3200, colour, liquid crystal shutter.
James. 04:54:11 - 04:55:11 UT, stack of two consecutive 30 s exposures. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
James. 23:37:37 - 23:38:07 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
The trail was not imaged by Alan due to obstructions to his view east.
Alan. 05:09 - 05:10 UT, 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 3200, colour, liquid crystal shutter.
The trail is barely visible due to thin cloud. The complete passage lasted from 05:08 to 05:17 UT.
Alan. 21:33 - 21:35 UT, stack of two consecutive 58 s images. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 3200, colour, liquid crystal shutter.
Alan. 05:54:29 - 05:55:27 UT, 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 3200, colour, liquid crystal shutter.
Similar trails, although shorter, were captured on subsequent nights.
Alan. 04:51:59 - 04:52:57 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 3200, colour, liquid crystal shutter.
The object was also imaged by Benelux observers, who estimated the trail at magnitude -1 and the terminal flare at magnitude -2.
Alan. 21:51:39 - 21:52:37 UT, 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 3200, colour, liquid crystal shutter.
Alan. 04:51 - 04:52 UT, 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 6400, colour, liquid crystal shutter.
Alan. 02:57 - 02:58 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 6400, colour, liquid crystal shutter.
Alan. 19:22:59 - 19:23:57 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 3200, colour, liquid crystal shutter.
Top: Alan. 01:47:11 - 01:48:09 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour. The trail appears segmented by the LCD light gate recently fitted to the camera.
Bottom: James. 01:47:33 - 01:48:03 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Cloud and lack of stars visible in the vicinity prevented a triangulation.
Alan. 03:40 - 03:41 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 3200, colour, liquid crystal shutter.
James. 05:11:26 - 05:11:56 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Top: Alan. 23:31:19 - 23:32:17 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Middle: James. 23:32:05 - 23:32:35 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Bottom: estimates of the meteor track over the northern France. Yellow: triangulation of James's and Alan's observations shows a descent from 96 km to the terminal flare at 54 km. Blue: triangulation of Alan's observation with one from a Benelux observer shows a notably different track with a descent from 90 km to 69 km. The baseline between James and Alan is too short for accurate triangulation, so the blue estimate should be the more accurate of the two.
Top: Alan. 06:16 - 06:17 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Middle: James. 06:16:44 - 06:17:14 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Bottom: triangulated path of the meteor over Suffolk, descending from an altitude of 78 km to 68 km.
Top: Alan. 04:59:02 - 05:00:00 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Middle: James. 04:59:19 - 04:59:49 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Bottom: triangulated path of the meteor NE to SW off the coast of Essex, descending from 91 km to 79 km.
James. 04:11:43 - 04:12:13 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Unfortunately, the area of the sky was behind considerable cloud. The meteor was also captured by Alan (behind cloud), by a member of the Benelux meteor group (no cloud) and by others. There were too few background stars visible through the cloud to enable triangulation.
James. 06:41:44 - 06:42:14 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Alan. 05:22 - 05:23 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Top: Alan. 03:24:17 - 03:25:15 UT, single 58 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Middle: James. 03:24:51 - 03:25:21 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Bottom: triangulated path of the meteor over France and the North Sea showing a descent from 216 km to 60 km. The baseline between James and Alan is too short for accurate triangulation, so the results should be regarded as broadly indicative. The estimated initial altitude is much higher than that at which a meteor would typically start ablating.
Top: Alan. 3:13:12 - 03:14:10 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Bottom: James. 03:13:12 - 03:13:42 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
James. 05:54:26 - 05:55:57 UT, stack of three consecutive 30 s exposures. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
The imaging run overnight on 02-03 December 2019 was the first successful all-night run of the camera with software tailored to the task in hand (a full rewrite of Thomas Jacquin's excellent code used formerly).
Alan. 17:41 - 17:42 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Alan. 05:53:47 - 05:54:45 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Alan. circa 04:55 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Alan. 03:53 - 03:54 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
James. 04:24:13 - 04:25:13 UT, stack of two consecutive 30 s exposures. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Top: Alan. 02:11:53 - 02:12:50 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Middle: James. 02:12:32 - 02:13:02 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Bottom: estimates of the meteor track over the North Sea. Yellow: triangulation of observations by James and Alan shows a descent from 113 km altitude to the terminal flare at 102 km. Blue: triangulation of observations by Alan and a Benelux observer shows a descent from approximately the same starting point but on a different trajectory and with the terminal flare at 87 km altitude. The baseline between James and Alan is too short for accurate triangulation, so the blue estimate should be the more accurate of the two. Benelux observers estimated the trail at magnitude -3 and the terminal flare at magnitude -6.
Top: Alan. circa 00:44 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Bottom: James. 00:43:23 - 00:43:53 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Although imaged by both Alan and James, there were too few stars visible in the vicinity to enable a triangulation to be performed.
James. 04:28:34 - 04:29:04 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Top: Alan, 00:47 - 00:49 UT, single 81 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Middle: James, 00:48:46 - 00:48:56 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Bottom: triangulated path south to north over Suffolk and Norfolk, dropping from an initial altitude of 104 km to a final altitude of 92 km. Initially, the object was classified as a satellite; however, the triangulation showed it to be a fireball. (A satellite could not orbit at an altitude of circa 100 km due to the atmospheric drag that it would experience.)
Alan. 03:54 - 03:56 UT, single 81 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Alan. circa 03:16 UT, single 81 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Alan. 20:07 - 20:09 UT, single 81 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
James. 02:48:39 - 02:49:09 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Top: Alan, 21:49 - 21:50 UT, single 81 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Middle: James, 21:49:46 - 21:50:16 UT, single 30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Bottom: triangulated path north to south over Suffolk, dropping from an initial altitude of 125 km to a final altitude of 79 km.
Top: Alan, 20:15:44 - 20:17:00 UT, single 76 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Middle: James, 20:15:39 - 20:16:09 UT, single30 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Bottom: triangulated path north to south over Kent, dropping from an initial altitude of 84 km to a final altitude of 77 km.
Alan. 23:17 - 23:19 UT, single 76 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Alan. 23:24 - 23:25 UT, single 76 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Alan. 20:50 - 20:57 UT, stack of five consecutive 76 s exposures. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Top: Alan. 01:20 - 01:21 UT, single 150 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Bottom: James. 01:20:21 - 01:21:21 UT, stack of three consecutive 20 s exposures. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
James. 01:33:30 - 01:33:50 UT, single 20 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Alan. 00:02 - 00:03 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
James. 00:44:56 - 00:45:16 UT, single 20 s exposure. ZWO ASI 178MC with ZWO fisheye lens, f1.2, gain 200, colour.
Alan. 23:58 - 23:59 UT, single 57 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f4, ISO 800, colour.
Alan. 00:57 - 00:59 UT, single 150 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Alan. 00:57 - 00:59 UT, single 150 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Top: Alan. 01:09:24 - 01:11:25 UT, single 150 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Bottom: James. 01:08:50 - 01:09:51 UT, stack of six consecutive 10 s exposures. RPi and PiCamera v2, ISO 800, monochrome.
Alan. 02:55 - 02:57 UT, single 150 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
James. 21:03:00 - 21:03:10 UT, single 10 s exposure. RPi and PiCamera v2, ISO 800, monochrome.
Alan. 21:45 - 21:47 UT, single 150 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f4.0, ISO 800, colour. (The lens was stopped-down slightly compared to its usual setting because of the bright moonlight.)
Alan. 03:51 - 03:53 UT, single 150 s exposure. Canon 1100d with 4.5 mm Sigma fisheye lens f2.8, ISO 800, colour.
The object was also imaged by members of UKMON, NEMETODE and the BAA. Triangulation of images by UKMON placed the object above Lincolnshire, UK.
Top: James. 00:40:01 - 00:41:02 UT, stack of six consecutive 10 s exposures. RPi and PiCamera v2. ISO 800, monochrome.
Bottom: Alan. 4.5 mm Sigma fisheye lens, 150 s exposures, f2.8, ISO 800, colour. Images on three consecutive nights as follows:
James. 21:47:18 - 21:47:28 UT, single 10 s exposure.
Alan. 20:14 - 20:16 UT, single 150 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens f2.8, ISO 800, colour.
Top: Alan. 03:13 - 03:15 UT, single 117 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens f2.8, ISO 800, colour.
Bottom: James. 03:13:48 - 03:14:09 UT, stack of two consecutive 10 s exposures. RPi and PiCamera v2, ISO 800, monochrome.
The inset in the lower image compares images by James (LHS) and Alan (RHS) in the region of the flare. Clearly, the flare shows minimal parallax relative to the nearby triangle of stars formed by θ, 17 and 21 Boötes, indicating that the object responsible is at an altitude of several hundred kilometres and must therefore be a satellite rather than a meteor.
James. 04:59:53 - 05:01:25 UT, stack of nine consecutive 10 s exposures. RPi and PiCamera v2, ISO 800, monochrome.
Alan. 20:09 - 20:11 UT, single 150 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Alan. 20:55 - 20:57 UT, single 150 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
The object was initially missed on examination of the night's images and was spotted on a more thorough examination following a report by a visual observer. A 60% waxing Moon creates a bright background sky.
Alan. 03:02 - 03:04 UT, single 150 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Alan. 17:37 - 17:40 UT, single 150 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens f2.8, ISO 800, colour. The image was captured approximately 10 minutes after the image immediately below.
Alan. Bottom: 17:21 - 17:24 UT, top: 17:24 - 17:27 UT. Both frames are 150 s exposures. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Top: Alan. 05:38 - 05:40 UT, single 150 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Middle: James, 05:38:40 - 05:38:50 UT, single 10 s exposure, ISO 800, monochrome. RPi and PiCamera v2, background stars labelled.
Bottom: this was the first occasion on which both cameras imaged a meteor, so it was possible to calculate a triangulation. The trajectory was from west to east over Essex, dropping from an initial height of 111 km with the terminal flare just south of Sudbury at an altitude of 84 km.
James. 19:04:00 - 19:04:10 UT, single 10 s exposure. RPi and PiCamera v2, ISO 800, monochrome.
James. 05:20:46 - 05:21:47 UT, stack of six consecutive 10 s exposures. RPi and PiCamera v2, ISO 800, monochrome.
James. 18:41:03 - 18:43:06 UT, stack of twelve consecutive 10 s exposures. RPi and PiCamera v2, ISO 800, monochrome.
Alan. 04:36 - 04:39 UT, single 150 s exposure. Canon 1100D with 4.5 mm Sigma fisheye lens, f2.8, ISO 800, colour.
Top: James. 03:03:38 - 03:03:48 UT, single 10 s exposure. RPi and PiCamera v2, ISO 800, monochrome. The two streaks (circled) were initially thought to be meteor trails.
Middle: Alan. 03:02 - 03:04 UT, single 150 s exposure. Canon 1100D with 10-18 mm Canon zoom lens set to 10 mm, f4.5, ISO 800, colour (contrast stretched).
Bottom: the brighter streak (red) in the James's image also appeared in Alan's. Adjusting both images to a common scale and orientation and overlaying them shows no discernible parallax. The brighter, shorter trail is from James's image and the fainter, longer one from Alan's). This indicates that the object responsible was at an altitude of several hundred km, too high for a meteor.
James. 02:18:29 - 02:18:39 UT, single 10 s exposure. RPi and PiCamera v2, ISO 800, monochrome.
Alan. 20:10 - 20:12 UT, single 150 s exposure. Canon 1100D with 10-18 mm Canon zoom lens set to 10 mm, f4.5, ISO 800, colour.
James. 19:21:04 - 19:21:14 UT, single 10 s exposure. RPi and PiCamera v2, ISO 800, monochrome.
Alan. 19:48 - 19:50 UT, single 150 s exposure. Canon 1100D with 10-18 mm Canon zoom lens set to 10 mm, f4.5, ISO 800, colour.
Alan. 19:33 - 19:35 UT, single 150 s exposure. Canon 1100D with 10-18 mm Canon zoom lens set to 10 mm, f4.5, ISO 800, colour.
The craft allegedly carries an optical telescope in excess of 2.5 m aperture, theoretically able to image objects as small as 5 cm on the surface of the Earth!
Alan. 20:02 - 20:05 UT, single 150 s exposure. Canon 1100D with 10-18 mm Canon zoom lens set to 10 mm, f4.5, ISO 800, colour.
Alan. Time not recorded. Single exposure. Canon 1100D with 10-18 mm Canon zoom lens set to 10 mm, 150 s exposure, f4.5, ISO 1600, colour.
Alan. 22:03 - 22:06 UT, single 300 s exposure. Canon 1100D with adapter-Helios-Spiratone lens combination, f11, ISO 1600, colour.
Alan. 02:13 - 02:18 UT, single 300 s exposure. Canon 1100D with adapter-Helios-Spiratone lens combination, f11, ISO 1600, colour.
Alan. 00:04 - 00:09 UT, single 300 s exposure. Canon 1100D with adapter-Helios-Spiratone lens combination, f11, ISO 1600, colour.
The night of 11-12 August was the only one offering clear skies around the time of the Perseid maximum in 2018. The sky was very transparent following two days of heavy rain which had washed the atmosphere clear of dust, and the Moon was new on 11 August so did not interfere with observations. Although the camera did not record any meteors, it did catch several satellite trails, of which the brightest is to the right.
James. 23:15 UT, single 8 s exposure. Canon 6D MkII, 24-105 mm lens at 24 mm, f3.5, ISO 4000, colour.
James. 22:52 UT, single 8 s exposure. Canon 6D MkII, 24-105 mm lens at 24 mm, f3.5, ISO 4000, colour.
Alan. 00:07 - 00:12 UT, single 300 s exposure. Canon 1100D with adapter-Helios-Spiratone lens combination, f11, ISO 1600, colour.
Alan. 22:48 - 22:54 UT, single 300 s exposure. Canon 1100D with adapter-Helios-Spiratone lens combination, f11, ISO 1600, colour.
This is the first colour image with Alan's camera. It was taken through thin cloud.
Alan. 00:14-00:19 UT, single 300 s exposure. Canon 1100D with adapter-Helios-Spiratone lens combination, f11, ISO 1600, monochrome.
Alan. 23:08 - 23:13 UT, single 300 s exposure. Canon 1100D with adapter-Helios-Spiratone lens combination, f11, ISO 1600, monochrome.
Alan. 23:07 - 23:12 UT, single 300 s exposure. Canon 1100D with adapter-Helios-Spiratone lens combination, exposure, f11, ISO 1600, monochrome.
James. 21:14 UT, single 5 s exposure. Canon 6D MkII, 24-105 mm lens at 24 mm, f3.5, ISO 4000, colour.
Alan. 16 Jun 2018, approx 22:30 UT, single 300 s exposure. Canon 1100D with adapter-Helios-Spiratone lens combination, f11, ISO 800, monochrome.
Trails created by aircraft and satellites are far more numerous in the night sky than those associated with meteors! An image from James's camera of 5 s duration, captured on the evening of 03 July 2018 (see above), showed five satellite trails! A later image, of 8 s duration, taken on 10 August 2018 (see above), showed typical trails from both satellites and aircraft.
Aircraft trails are easily recognised by the characteristic patterns of their navigation lights. Satellites in orbit appear as points of light or trails in time-exposure photographs. The most prominent satellite is the ISS, which can create a trail as bright as magnitude -6.0 extending over much of an arc of the sky. Initially, Alan and James found it difficult to reliably differentiate between trails created by satellites and meteors and, indeed, identified many satellites erroneously as meteors. Fortunately, with practice, their powers of discrimination improved! In general, satellite trails are symmetric, smooth and of a single hue (reflected sunlight), whereas meteor trails are asymmetric (often with a terminal flare), sometimes show internal structure and can exhibit varying colours as different gasses are ablated by the passage of the body through the atmosphere.
A meteor moves much faster through the sky than does a satellite so, when the camera is equipped with a shutter, the trail created by a satellite appears smooth, without breaks, whereas that created by a meteor appears segmented.
[1]
Zdenek Ceplecha, "Geometric, Dynamic, Orbital And Photometric Data On Meteoroids From Photographic Fireball Networks", Bull. Astron. Inst. Czechosl. 38 (1987), 222-234.
[2]
Denis Vida, 2016, Python programme for meteor triangulation, https://github.com/CroatianMeteorNetwork/CMN-codes/blob/master/triangulation/MeteorTriangulation.py.
Alan Smith, James Appleton