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HD 209458 b

HD 209458 · G0 V · 6091 K
Modelled Radial Velocity

Planet data ()

Colour ·
Base hex
Reflected brightness (Y)
Confidence
Out of sRGB gamut
Planet
Equilibrium temp1459 K
Radius15.58 R⊕
Mass232.0 M⊕
Semi-major axis0.047 AU
DiscoveryRadial Velocity · 1999
Both colours are modelled predictions, not photographs. The full-spectrum swatch is our most complete model; the Roman view is coarser (four bands). This planet's light has never been isolated by any telescope.

Render fidelity + style are on the scope controls below. Spectrum engine: PICASO radiative transfer. Model assumptions — cloud state: hot, cloud-free, alkali (sodium) absorption; metallicity: 1.0× solar; phase angle: 0°.
◼ EXOSCOPE HD 209458 b · reflected-light · 380–780 nm VIEW
Roman is blind here 0.080.170.250.33 380 nm 780 nm
CH1 FULL
CH2 ROMAN #fbbcbb
ΔE2000 39.8
Y BRIGHT
CONF
GAMUT
ΔE = perceptual distance (full vs Roman). <575 nm: Roman blind, flat-held.
RENDER CONTROLS
Style
Shape
PALETTE ▸
#00335c
#0061ad
#008fff
#70c0ff
#c2e4ff
#570605
#a40c0a
#fbbcbb
#f77a78
#fcc6c5
.ASE
Colours derived from reflected-light albedo models × host-star spectra via CIE 1931 colour matching. Modelled, not photographed. Data: NASA Exoplanet Archive.