CBERS 2B flash pattern

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Last night I set up the camera with a Tamron 2.8/17-50mm lens set at f3.2/17mm to run automatically (using an Aputure timer), in order to catch some Perseids.

AS part of the image series, I captured a satellite showing a regular flash pattern. The top image above is a stack of 7 images of 20s each, showing the repeated flashing (including a brighter flare).

It turned out to be CBERS 2B (07-042A) which was launched from China on 19 September 2007 as the third Chinese-Brazilian Earth Resources Satellite. It ceased operations in June 2010.

By measuring the positions of the flashes and relating these to a recent TLE, I was able to determine the flash pattern. It is a combination of two series: one with flashes each 23.7s (series a), and another one (which includes the bright flare) with flashes each 47.4s (series b). The latter is the double of the series a period. The sequence of flashes is a-a-b-a-a-b-a-a-b but the b-flashes are not nicely in the middle of the a-series flashes.

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The two series probably relate to different reflective surfaces. The flashes from series a are conspicuously orange, while those from series b are bluish-white.

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As can be seen on the CBERS website, the satellite body itself is wrapped in orange insulation foil, suggesting the orange flashes could be reflections from the satellite body. The bluish-white flashes could be from the solar panels. The satellite would then rotate once each 94.8 seconds during which 2 solar panel flares and 4 body flares (4 sides of the cubus) can be seen.

CBERS 2B was not the only satellite captured flaring this night: I'll report on the other later. Amongst others, Envisat was seen flaring again.

Perseids

I indeed captured some meteors as well: 7 Perseids and one sporadic meteor. Here is a nice Perseid:

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