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

Positions of STEREO A and B for 19-Jan-2025 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)      1.008910        0.983973        0.965817        0.649447        0.915744        0.453855
Semidiameter (arcsec)            951.153         975.258         993.592        1477.607        1047.921        2114.393

HCI longitude                      5.786          43.575          72.804         238.752          25.414         183.203
HCI latitude                      -0.542          -5.015          -7.046           3.324           0.807          -3.140

Carrington longitude             151.893         189.682         218.911          24.859         171.521         329.310
Carrington rotation number      2293.578        2293.473        2293.392        2293.931        2293.524        2293.085

Heliographic (HEEQ) longitude    -37.789          -0.000          29.229        -164.822         -18.161         139.628
Heliographic (HEEQ) latitude      -0.542          -5.015          -7.046           3.324           0.807          -3.140

HAE longitude                     81.574         119.571         148.703         314.533         100.910         258.547

Earth Ecliptic (HEE) longitude   -37.997          -0.000          29.133        -165.038         -18.661         138.976
Earth Ecliptic (HEE) latitude      0.195          -0.000          -0.113          -2.880           3.910          -3.522

Roll from ecliptic north           0.250                           0.200
Roll from solar north              7.464                           2.339

Light travel time to Earth (min)           5.400           4.081                  13.471           2.674          11.303

Separation angle with Earth               37.997          29.133                 164.769          19.052         138.852
Separation angle A with B                         67.130

Carrington rotation 2293 runs from 2025-01-06 19:35 (DOY   6.82) to
2025-02-03 03:45 (DOY  34.16), as seen from Earth.

Last Revised: Sunday, 19-Jan-2025 18:01:56 UTC
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