Positions of STEREO A and B for 25-Sep-2026 15:00 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)      1.084348        1.002835        0.965853        0.591279        0.689182        0.470508
Semidiameter (arcsec)            884.981         956.914         993.554        1622.970        1392.416        2039.559

HCI longitude                    217.696         286.555         356.406         234.847         329.006         177.363
HCI latitude                       4.298           6.954           0.374           3.183          16.286          -3.252

Carrington longitude             296.354           5.214          75.065         313.506          47.665         256.021
Carrington rotation number      2316.177        2315.986        2315.791        2316.129        2315.868        2316.289

Heliographic (HEEQ) longitude    -68.859           0.000          69.851         -51.708          42.451        -109.193
Heliographic (HEEQ) latitude       4.298           6.954           0.374           3.183          16.286          -3.252

HAE longitude                    293.669           2.196          72.153         310.629          43.190         252.739

Earth Ecliptic (HEE) longitude   -68.526          -0.000          69.958         -51.567          40.994        -109.457
Earth Ecliptic (HEE) latitude     -0.153           0.000          -0.079          -2.752          12.465          -2.897

Roll from ecliptic north          -0.058                           0.029
Roll from solar north             -5.791                           7.267

Light travel time to Earth (min)           9.789           9.390                   6.544           5.653          10.325

Separation angle with Earth               68.526          69.958                  51.619          42.524         109.431
Separation angle A with B                        138.484

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: Friday, 25-Sep-2026 15:01:07 UTC
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