Observation by Derek Robson: Asteroid Florence

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Derek Robson


Derek Robson


2017 Sep 02 - 23:00


2018 Sep 22 - 16:59


3122 Florence

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Field centre

RA: 20h44m
Dec: +15°53'
Position angle: +22°37'

Field size

0°45' × 0°56'

  • Canon 1100d/Tamron 70-300 mm lens


Target name



Asteroid Florence

About this image

Stack of 36 exposures, and final crop of stack, inverted to negative. Direction of motion of Florence shown by red arrow.

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Derek Robson
Derek Robson, 2018 Sep 22 - 17:09 UTC


Grant Privett
Grant Privett, 2018 Sep 22 - 22:46 UTC

Were there any missed exposures or are the gaps in the trail due to real brightness variations? How long are the exposures and are they all evenly spaced?

Derek Robson
Derek Robson, 2018 Oct 05 - 03:25 UTC

Grant. I need to look up the conditions used.

Derek Robson
Derek Robson, 2019 Aug 11 - 14:04 UTC

Gaps are not due to change in brightness, but rather, due to deliberately taking longer exposures (3.2-20s) at certain times in the period and also frames which had drifted too far outside the target area (undriven mount, just a tripod); both were excluded from the stack.

Exposure 2s, f5.6, ISO 6400.  Not all evenly spaced, but most were aimed at every 1 min.

Period 1hr 8m.  00:41-01:49hr 3/9/17.  Total images taken 49. 36 used to stack.  5 darks taken.

Focused on Altair for lens focus prior to use.

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