The Sun's views

What each of the 21 live views on the Sun tab shows, and what to look for in it.

The Sun tab shows the Sun as several spacecraft see it. Each view picks out a different temperature or layer. Å (ångström) is a unit of wavelength: one tenth of a nanometre.

The quick look

AIA 211·193·171: three ultraviolet channels (about 0.6 to 2 million °C) combined. Coronal holes stand out as dark areas and active regions as bright knots: the quickest view of what could affect Earth over the next few days.
SUVI map: NOAA's map from GOES-19 that sorts the Sun into quiet Sun, active regions, coronal holes, filaments, prominences and flares, each in its own colour.

Coronal holes and the corona

AIA 193 Å: iron at about 1.5 million °C, showing the corona. Coronal holes are the large dark areas; when one faces Earth, fast wind usually arrives 2 to 4 days later.
AIA 211 Å: iron at about 2 million °C. Active regions glow and coronal holes show with sharper edges than at 193 Å.
SUVI 195 Å and SUVI 284 Å: similar views from NOAA's GOES-19, with a wider field that shows loops and eruptions beyond the edge of the Sun. 284 Å shows coronal holes with strong contrast.
AIA 171 Å: the corona at about 600,000 °C. Bright arcs are coronal loops above active regions; tangled loop systems mark where flares are most likely.

Active regions and flares

AIA 131 Å: the hottest material, about 10 million °C. A flare shows as a sudden, very bright spot.
AIA 94 Å: about 6 million °C, the hot cores of active regions. Regions that stay bright here are the ones to watch.
AIA 335 Å: about 2.5 million °C. Dimmer and grainier, but shows the heating above complex sunspot groups.
AIA 1600 Å: the top of the surface and just above. During a flare, bright ribbons appear where its energy reaches the lower atmosphere.
AIA 1700 Å: the surface itself; bright patches around sunspots trace the magnetic field.

Sunspots and magnetic field

HMI: the Sun in visible light, as through a solar filter. Sunspots are darker, cooler patches where strong magnetic fields hold back heat. Each group is labelled with its NOAA region number.
HMI magnetogram: the magnetic field at the surface, with the two polarities in contrasting colours. Tightly packed opposite polarities store the most energy and produce most large flares.

Prominences and filaments

AIA 304 Å: helium at about 50,000 °C, low in the atmosphere. Prominences are clouds of cooler gas above the edge of the Sun; seen against the disc they're dark threads called filaments. An erupting filament can launch a CME.

CMEs: the coronagraphs

A coronagraph blocks the bright disc to show the faint corona around it, where CMEs appear as expanding bright clouds. A ring spreading all around the disc, a halo CME, is heading towards Earth or directly away from it.

LASCO C2: SOHO's view out to about six times the Sun's radius.
LASCO C3: a much wider view, out to about 30 times the radius. Bright dots are stars and planets.
CCOR-1: NOAA's coronagraph on GOES-19, built for space weather forecasting.
CCOR-2: NOAA's coronagraph on SOLAR-1 (formerly SWFO-L1), 1.5 million km towards the Sun.
CCOR-1 Δ and CCOR-2 Δ: each image minus the one before, so only changes show. A CME appears as a bright front with darkness behind it: the easiest way to spot one.

Images arrive on each spacecraft's own schedule. See Why are some Sun images an hour old?