Processing the 21 Jul Centaurus A data showed the nucleus is saturated: a
single 300 s luminance sub reads 65313 ADU in the core, so the deep stack
is clipped there and the core cannot be recovered by processing. The only
fix is more data at shorter exposures.
plans/hdrcore-t32.txt is that data: L 8x60s, 8x15s and 8x5s plus RGB
5x30s, all BIN2 so the frames register against the deep stack without
rescaling. The ladder spans a factor of 60 below the 300 s subs, which
covers the unknown true peak of the nucleus, and the RGB gives the core
its colour. 18.2 minutes of imaging, about 25 points.
Uploaded to T32 and verified byte-identical, then booked for the evening
of 22 Jul, 18:50-19:50 SSO local, which is the same window in which the
deep run actually succeeded (T32 has a 35 degree elevation floor and Cen A
is an evening target). Verified in MySummary; quota now 7:05 of 8:00.
The wider point is recorded in CAMPAIGN.md: bright targets need a short
set budgeted alongside the deep run. NGC 6744 has already been shot
without one, and 47 Tuc and the SMC in queue #5 will certainly need one,
a globular cluster core being the fastest thing there is to saturate.
Laurence
7bf834a184