Positions of STEREO A and B for 9-Jan-2026 09:00 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)      1.028115        0.983404        0.964933        0.657051        0.809530        0.452094
Semidiameter (arcsec)            933.386         975.823         994.502        1460.507        1185.413        2122.626

HCI longitude                    332.964          32.766          83.933         239.317          40.782         205.576
HCI latitude                       3.484          -3.943          -7.313           3.343           0.902          -2.436

Carrington longitude             128.928         188.730         239.897          35.281         196.746           1.540
Carrington rotation number      2306.642        2306.476        2306.334        2306.902        2306.453        2305.996

Heliographic (HEEQ) longitude    -59.802          -0.000          51.166        -153.449           8.016         172.810
Heliographic (HEEQ) latitude       3.484          -3.943          -7.313           3.343           0.902          -2.436

HAE longitude                     48.524         108.742         159.748         315.097         116.234         280.884

Earth Ecliptic (HEE) longitude   -60.219           0.000          51.006        -153.645           7.492         172.142
Earth Ecliptic (HEE) latitude      0.176          -0.000          -0.101          -2.898           5.630          -5.547

Roll from ecliptic north           0.103                           0.078
Roll from solar north              6.558                           0.843

Light travel time to Earth (min)           8.399           6.979                  13.295           1.886          11.903

Separation angle with Earth               60.219          51.006                 153.497           9.362         170.392
Separation angle A with B                        111.225

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 09:01:07 UTC
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