Positions of STEREO A and B for 26-Dec-2025 05:00 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)      1.037652        0.983529        0.966058        0.459707        0.873662        0.462853
Semidiameter (arcsec)            924.807         975.699         993.344        2087.478        1098.396        2073.287

HCI longitude                    319.647          18.404          69.144         226.342          28.264         165.441
HCI latitude                       4.859          -2.304          -6.899           2.825           4.626          -3.365

Carrington longitude             316.557          15.314          66.054         223.252          25.174         162.351
Carrington rotation number      2306.121        2305.957        2305.817        2306.380        2305.930        2305.549

Heliographic (HEEQ) longitude    -58.757           0.000          50.739        -152.062           9.860         147.037
Heliographic (HEEQ) latitude       4.859          -2.304          -6.899           2.825           4.626          -3.365

HAE longitude                     35.171          94.309         145.067         302.125         103.319         240.908

Earth Ecliptic (HEE) longitude   -59.137          -0.000          50.759        -152.183           9.010         146.599
Earth Ecliptic (HEE) latitude      0.151           0.000          -0.116          -2.429           8.027          -1.524

Roll from ecliptic north           0.093                           0.092
Roll from solar north              5.613                           2.668

Light travel time to Earth (min)           8.305           6.951                  11.697           1.858          11.589

Separation angle with Earth               59.137          50.759                 152.086          12.045         146.568
Separation angle A with B                        109.896

Carrington rotation 2305 runs from 2025-11-30 01:08 (DOY 334.05) to
2025-12-27 08:54 (DOY 361.37), as seen from Earth.

Last Revised: Friday, 26-Dec-2025 05:01:08 UTC
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