Information about STEREO-A close approach to Earth, August 2023

Positions of STEREO A and B for 2-Apr-2025 07:00 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)      1.006247        0.999588        0.958032        0.403957        0.296731        0.444101
Semidiameter (arcsec)            953.670         960.023        1001.666        2375.569        3234.004        2160.834

HCI longitude                     78.285         116.862         148.846         222.344         207.315         144.556
HCI latitude                      -7.067          -6.475          -3.740           2.634          -4.900          -3.221

Carrington longitude             275.432         314.009         345.993          59.491          44.462         341.703
Carrington rotation number      2296.235        2296.128        2296.039        2295.835        2295.876        2296.051

Heliographic (HEEQ) longitude    -38.576           0.000          31.985         105.482          90.453          27.694
Heliographic (HEEQ) latitude      -7.067          -6.475          -3.740           2.634          -4.900          -3.221

HAE longitude                    154.141         192.442         224.411         298.128         282.338         220.207

Earth Ecliptic (HEE) longitude   -38.301           0.000          31.968         105.685          89.896          27.764
Earth Ecliptic (HEE) latitude      0.037          -0.000           0.024          -2.257          -8.193           0.992

Roll from ecliptic north           0.044                          -0.041
Roll from solar north              1.512                          -6.242

Light travel time to Earth (min)           5.473           4.496                   9.772           8.668           5.332

Separation angle with Earth               38.301          31.968                 105.673          89.897          27.781
Separation angle A with B                         70.269

Carrington rotation 2296 runs from 2025-03-29 19:19 (DOY  88.80) to
2025-04-26 01:47 (DOY 116.07), as seen from Earth.

Last Revised: Wednesday, 02-Apr-2025 07:01:06 UTC
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