Positions of STEREO A and B for 9-Jan-2026 13:00 UT

This figure plots the current positions of the STEREO Ahead (red) and Behind (blue) spacecraft relative to the Sun (yellow) and Earth (green). The dotted lines show the angular displacement from the Sun. Units are in A.U.

When the two spacecraft are close to Earth, an expanded view of the region around Earth will appear on the right, in the same orientation as the Sun-centered view.

Other resources:

• STEREO Orbit Tool
• STEREO-A Fly-by Orbit Tool for Summer 2023
• STEREO-A roll angle during Fly-By
• STEREO orbit simulations
• Satellite Situation Center (SSCWeb)
• HelioWeb
• Attitude and orbit text files (CalTech)
• Early orbit summary
• Connections with Parker Solar Probe
• Explanation of coordinate systems

                                STEREO-B           Earth        STEREO-A       Parker SP   Solar Orbiter     BepiColombo

Heliocentric distance (AU)      1.028006        0.983410        0.964918        0.658532        0.808537        0.451660
Semidiameter (arcsec)            933.485         975.817         994.518        1457.222        1186.869        2124.671

HCI longitude                    333.122          32.935          84.107         239.429          40.942         206.068
HCI latitude                       3.467          -3.961          -7.315           3.347           0.854          -2.415

Carrington longitude             126.722         186.536         237.707          33.029         194.542         359.669
Carrington rotation number      2306.648        2306.482        2306.340        2306.908        2306.460        2306.001

Heliographic (HEEQ) longitude    -59.814          -0.000          51.171        -153.507           8.007         173.133
Heliographic (HEEQ) latitude       3.467          -3.961          -7.315           3.347           0.854          -2.415

HAE longitude                     48.682         108.912         159.921         315.209         116.398         281.378

Earth Ecliptic (HEE) longitude   -60.230          -0.000          51.009        -153.703           7.487         172.466
Earth Ecliptic (HEE) latitude      0.176           0.000          -0.101          -2.901           5.597          -5.583

Roll from ecliptic north           0.103                           0.078
Roll from solar north              6.567                           0.821

Light travel time to Earth (min)           8.400           6.979                  13.309           1.890          11.902

Separation angle with Earth               60.230          51.009                 153.554           9.338         170.632
Separation angle A with B                        111.239

Carrington rotation 2306 runs from 2025-12-27 08:54 (DOY 361.37) to
2026-01-23 16:59 (DOY  23.71), as seen from Earth.

Last Revised: Friday, 09-Jan-2026 13:01:10 UTC
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