AKATSUKI returns to Venus

Earth, Planets and Space

Table 1 Summary of the Venus observations taken immediately after the VOI-R1 operation

	IR1	UVI	LIR
Observation date Observation time (UT)	December 7, 2015 4:51:56	December 7, 2015 5:19:53	December 7, 2015 5:26:02
Wavelength	0.90 μm^a	283 nm	10 μm
Exposure time (s)	3.0	0.25	34^b
Distance between AKATSUKI and Venus (km)	6.8 × 10⁴	7.2 × 10⁴	7.3 × 10⁴
Apparent diameter (°)^c	10.4	9.7	9.6
Spatial resolution (km/pixel)^d	14.2	15.1	63.9
Sub-observer point
Latitude (°)	−6.7	−6.6	−6.6
Longitude (°)	96.4	95.1	94.9
Solar phase angle (°)	45.0	46.3	46.6
Subsolar point
Latitude (°)	−2.6	−2.6	−2.6
Longitude (°)	141.4	141.5	141.5
Solar phase angle (°)	48.9	50.0	50.2

^aThe filter for dayside imaging was used
^bThe composite image was made by superimposing 32 images. Exposure time for an image was 1.1 s
^cA tangent height assumed to be 70 km from the surface was added to the radius of Venus (6051.8 km)
^dSpatial resolution was calculated with the pixel scale of 0.012 (°/pixel) for IR1 and UVI and 0.05 (°/pixel) for LIR