Some mysteries
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A recent astrophotography session threw up 2 very curious frames. I have some ideas as to what they are but see what you think first.
Object 1
Here is the first one, the right hand part of a vertical 21-megapixel frame scaled down. The bright star is Alpha Cassiopeiae and north is at the top. The object was heading pretty accurately due north or due south. It is impossible to tell which direction. The irregular wobble seems too large for a satellite. Exposure time was 10s.
Canon EOS5DMkII 254mm Newtonian @ 1200mm 10s f/4.8 ISO25600 2009:12:10 18:09:08 GMT
Following is a cropped portion of the frame scaled to 100% (1 pixel here = 1 pixel in the camera). It is the edge of the original frame, so allow for the fact that I am using a short focal length Newtonian and there is therefore some inevitable distortion.
Canon EOS5DMkII 254mm Newtonian @ 1200mm 10s f/4.8 ISO25600 2009:12:10 18:09:08 GMT
Object 2
Here is the second mystery. This frame would cover M33 if conditions had been good enough to see it. (It was one of 100 exposures, the results from processing the other 99 of which can be seen here.) Exposure time was again 10s.
Canon EOS5DMkII 254mm Newtonian @ 1200mm 10s f/4.8 ISO6400 2009:12:10 19:14:06 GMT
And here is a 100% crop around the rightmost flashes. Note that the flashes must have been of extremely short duration because they are not elongated along the direction of travel at all. The way the trail stops indicates that the object was travelling from the bottom right of the frame. GRIP shows what the transverse profiles are like.
Canon EOS5DMkII 254mm Newtonian @ 1200mm 10s f/4.8 ISO6400 2009:12:10 19:14:06 GMT
Some thoughts on identification
Object 1 is moving almost exactly due north or south, which is suspicious for a meteor and it is the wrong direction for it to be a Geminid (the most likely meteors at the time). If it is a satellite why does it wobble so much? Tumbling? Atmospheric turbulence affecting the light? I doubt it could be the latter because object 2 was photographed only about an hour later and conditions had not changed as far as I could tell, yet its parallel tracks are quite straight. Also the star images, although poor (this was an accidental photo, when I was setting the camera), would be even worse.
The field is 2.4 degrees vertically, so object 1 travelled at a speed of at least 0.24 degrees per second. The amplitude of the wobble is about 0.02 degrees. At a height of 10 km that represents a lateral displacement of about 3.5m. Scale proportionally for other possible heights. What forces could be causing that?
Object 2 is unlikely to be an aircraft. It is not flashing periodically but with a pattern of 4 pairs of flashes, the first one brighter than the rest. Compare it with the aircraft I photographed here. It must be one object (2 parallel satellite orbits would be impossible - they would have to cross, like great circles on the earth).
Object 2 has travelled at least 1.65 degrees in 10s. The spacing between the tracks is 0.067 degrees. At a height of 10km that would be 11.7m. The spacing along the tracks between the first 2 pulses is 0.157 degrees. Between the other pulses it is slightly less: about 0.152 degrees. If they are nominally 1 second intervals the angular speed of the object is obvious. At a height of 10 km it would then be moving at 26.5m/s, or 95.5 km/h, too slow for an aircraft. 10 times higher it would be 10 times faster, etc. So how high would it need to be to be in orbit, ie a satellite rather than a plane?
The measurements here were made in GRIP, calibrating the images from GRIP-generated star charts of the same regions.