Positions of STEREO A and B for 15-Sep-2026 18:00 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)      1.082979        1.005604        0.965054        0.422240        0.586322        0.455844
Semidiameter (arcsec)            886.100         954.280         994.377        2272.709        1636.691        2105.168

HCI longitude                    209.272         276.835         346.252         223.735         312.372         149.655
HCI latitude                       3.393           7.201           1.668           2.702          16.842          -3.297

Carrington longitude              68.001         135.565         204.982          82.464         171.102           8.385
Carrington rotation number      2315.811        2315.623        2315.431        2315.771        2315.525        2315.977

Heliographic (HEEQ) longitude    -67.564           0.000          69.417         -53.101          35.537        -127.180
Heliographic (HEEQ) latitude       3.393           7.201           1.668           2.702          16.842          -3.297

HAE longitude                    285.216         352.547          61.919         299.518          26.920         225.262

Earth Ecliptic (HEE) longitude   -67.331           0.000          69.372         -53.029          34.372        -127.285
Earth Ecliptic (HEE) latitude     -0.170          -0.000          -0.060          -2.319          11.431           0.376

Roll from ecliptic north          -0.070                           0.024
Roll from solar north             -6.391                           7.067

Light travel time to Earth (min)           9.645           9.332                   6.855           5.267          11.079

Separation angle with Earth               67.331          69.372                  53.064          36.000         127.284
Separation angle A with B                        136.703

Carrington rotation 2315 runs from 2026-08-29 18:07 (DOY 241.75) to
2026-09-26 00:28 (DOY 269.02), as seen from Earth.

Last Revised: Tuesday, 15-Sep-2026 18:01:10 UTC
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