Positions of STEREO A and B for 6-Dec-2025 03:00 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)      1.051320        0.985352        0.967041        0.321551        0.899011        0.393079
Semidiameter (arcsec)            912.783         973.894         992.334        2984.367        1067.426        2441.312

HCI longitude                    301.107         358.127          48.297         283.328          12.189         101.005
HCI latitude                       6.320           0.235          -5.555           3.747           9.008          -1.647

Carrington longitude             222.887         279.907         330.077         205.108         293.969          22.785
Carrington rotation number      2305.381        2305.222        2305.083        2305.430        2305.183        2304.937

Heliographic (HEEQ) longitude    -57.020           0.000          50.170         -74.799          14.062         102.878
Heliographic (HEEQ) latitude       6.320           0.235          -5.555           3.747           9.008          -1.647

HAE longitude                     16.663          73.878         124.302         359.087          86.735         176.817

Earth Ecliptic (HEE) longitude   -57.215           0.000          50.424         -74.791          12.856         102.939
Earth Ecliptic (HEE) latitude      0.103           0.000          -0.125          -3.309          10.469           5.471

Roll from ecliptic north           0.070                           0.101
Roll from solar north              3.809                           4.918

Light travel time to Earth (min)           8.125           6.919                   7.927           2.362           9.476

Separation angle with Earth               57.215          50.424                  74.817          16.524         102.879
Separation angle A with B                        107.639

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: Saturday, 06-Dec-2025 03:01:09 UTC
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