WASP-54 b’s modelled colour is
periwinkle #c2ccde:
it is hot enough to have clouds again — not water, but rock: at these temperatures vaporised silicate condenses into a bright, glassy haze that throws the starlight back.
Full spectrum: the colour computed from the complete 380–780 nm reflected-light model.
Roman 3-band: the same planet as the 's would see it — half-lit (, the only geometry a coronagraph can catch; fully lit would hide behind the star) and through just four .
Both are modelled, not photographs; flipping between them shows how much of a planet's colour survives Roman's coarse filter set.
Classic: surface colour and brightness taken straight from the physics model (cloud bands are schematic).
Stylised: that same colour restyled into warm/cool bands and turbulence for looks: prettier, not more accurate.
The palette below is identical either way; only the picture changes.
Modelled: the planet as our physics computes it should look: a smooth globe in its derived colour. Not a photograph.
Telescope: the actual processed image astronomers took of this planet: a faint point of light beside its (blocked-out) star. It is almost always and ; the real dot humanity has received, not a picture of the surface.
Only a handful of planets have ever been photographed directly; that is why this knob appears on some pages and not others. When more than one telescope has imaged the same planet (e.g. JWST and, later, Roman), a small tab picks between them.
Light source: same planet, same atmosphere — a different lamp. A planet's colour is its reflectivity times the light falling on it, so part of every colour here belongs to the star, not the planet.
Its own star: lit by WASP-54
(6100 K, modelled as a ).
The Sun: the identical planet re-lit by our Sun (5772 K) —
around the Sun this world would come out
#c6ccd8.
The shift is 2.2 (0 = identical, above ~2 is visible to the eye). A visible change: some of this planet's native colour is really its star's tint, the rest is the planet's own.
Both are modelled, not photographed. The Roman 3-band channel has no Sun-lit version, so this knob acts on the full-spectrum view only.
Phase works like Moon phases: how much of the planet's lit side faces us. 0° is "full" (fully lit), 90° half lit, 180° "new" (backlit and dark). Both the brightness and the colour change as a planet wanes — and a coronagraph like Roman's can never see 0°, because a fully-lit planet sits right behind its star.
How this colour bends with phase is borrowed from the closest reference model (); the planet keeps its own full-phase colour.
#202a3c
#405375
#637dab
#9dadca
#d7deea
#252b37
#4a556b
#71809e
#a6afc2
#dbdee6
#392423
#704745
#a46d6a
#c6a3a2
#e8dad9
#d2cac9
the light this planet reflects
its real star:
At magnitude 10.4 this star is below the naked-eye limit (≈ 6.5 under a dark sky) — telescope territory. It still sits at these coordinates, in Virgo.
▸ Find WASP-54 in your sky tonight — every host star above your horizon right nowA planet's colour is mostly a consequence of where it is. Drag it inward and it heats up: methane breaks apart, cloud decks boil away, sodium starts eating the yellow out of its star's light. Drag it outward and everything freezes and condenses back. This slider re-runs the colour model at each distance and shows you the result.
Temperature is scaled from this planet's own as distance to the power of −½, holding the star fixed — so at its real orbit the slider reproduces the colour at the top of this page exactly, and moves away from there.
This is not a measurement. It is one model's opinion about a planet that is not where we put it.
The marks under the slider are the reference grid — independently published model spectra at 0.8, 2, 5 and 10 AU, the set the Roman Coronagraph community uses. Click one to jump there and compare. Where the two disagree, that gap is the honest size of the uncertainty — the grid models cloud condensation chemistry that our smooth model only approximates. The grid is computed for a Sun-like star, so its distances are used as published rather than rescaled for this host.
#c2ccde
where it really is
Nobody has measured this planet's clouds or its . The pipeline has to assume both to produce a colour at all, and it says so on every page. Here you can turn those assumptions and watch what they were worth.
Each swatch changes exactly one assumption and re-runs the model; everything else, including the planet's real temperature and its star, is held fixed. The number under each is , the standard measure of how far apart two colours look: below about 2 the eye cannot tell, above about 10 they are plainly different colours.
A planet whose swatches barely move is one where the assumptions do not matter much. One where they swing wildly is a planet whose colour you should trust less — and that is worth being able to see rather than being asked to take on trust.
#c2ccde
| Base hex | #c2ccde |
| Lit by its own star | |
| Out of |
| 1759 measured | |
| Radius | 17.71 measured |
| Mass | 187.5 measured |
| 0.05 measured | |
| Distance from Earth | 819.6 measured |
| Discovery | · 2012 |
△ TOO CLOSE — at 1,553× the starlight Earth receives, any surface water here would have boiled off long ago. The habitable zone lies further out, past 1.456 AU.