Photometric analysis of the TYC 0294-00111-1 occultation by (52)Europa.
Mar. 5, 2011
Kazuhisa Miyashita
Correction for light absorption by thin clouds.
Miyashita, Ikeda, Nagano (with 2 frames integration)
I observed (52)Europa occultation on Mar. 3, 2011 (UTC) at Ikeda, Kitaazumi, Nagano.
Thin clouds began to pass over the target star 30 minutes before the event.
So I set the TGV-M(WAT120) camera to gamma:Hi; integration:2 frames; gain:Max
to find and confirm the target star. And I started on capturing at 16h37m30s.
Although clear sky became again at just after to begin the recording,
I continued the recording with same setting as before to detect the event correctly.
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Fig.1 Raw right curve
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Figure 1 shows there are some light absorptions by thin clouds.
For correct it, the function of absopption correction with comparison star was applied.
The correction process is as follows.
1st. Moving average function is applied to comparison star. (Fig.2)
2nd. Absorption correction is applied based on averaged companion star. (Fig.3)
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Fig. 2 Preparing for correction. Companion star is moving averaged.
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Fig. 3 Correction for absorption is applied.
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Event time of occultation.
Event time of occultation is obtained from above analysis. The result is:
Appearance : 16h38m15.28s +/- 0.09s (UTC)
Disappearance : 16h38m42.34s +/- 0.10s (UTC)
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Fig. 4 Event time of disappearance
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Fig. 5 Event time of appearance
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