Open Access

Table 1

Keck/NIRC2 vortex coronagraph observation log.

Target filter Vega Ms band
UT date 2018 Aug. 30 2019 Aug. 20
UT start 05:15:26.35 06:35:47.62
UT end 07:15:00.52 10:12:23.95
Airmass (a) 1.066 ± 0.009 1.159 ± 0.101
DIMM seeing (a,b) 0″.42 ± 0″.11 1″.18 ± 0″.55
MASS seeing (a,b) 0″.16 ± 0″.06 0″.18 ± 0″.08
Precipitable water vapor level ~7 mm ~2 mm
Parallactic angle change 74°9 81°.6

Single integration time 0.181 s 0.25s
Coadd for single frame 100 150
Total frame count 110 120
On-target integration time 1991 s 4500 s
Total on-target time 1.803 h
Pixel scale 9.942 mas

Notes – (a)The uncertainties in this paper are 1σ unless otherwise specified. (b)Calculated during this observation using http://mkwc.ifa.hawaii.edu/current/seeing/index.cgi.

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