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

Positions of STEREO A and B for 3-Apr-2025 01:00 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)      1.006530        0.999799        0.957951        0.421104        0.299388        0.446025
Semidiameter (arcsec)            953.402         959.821        1001.750        2278.838        3205.303        2151.512

HCI longitude                     79.035         117.605         149.632         223.620         212.649         146.822
HCI latitude                      -7.088          -6.433          -3.652           2.697          -3.341          -3.257

Carrington longitude             265.544         304.114         336.141          50.129          39.158         333.331
Carrington rotation number      2296.262        2296.155        2296.066        2295.861        2295.891        2296.074

Heliographic (HEEQ) longitude    -38.570          -0.000          32.028         106.015          95.044          29.217
Heliographic (HEEQ) latitude      -7.088          -6.433          -3.652           2.697          -3.341          -3.257

HAE longitude                    154.886         193.182         225.200         299.404         287.848         222.454

Earth Ecliptic (HEE) longitude   -38.296          -0.000          32.018         106.222          94.666          29.271
Earth Ecliptic (HEE) latitude      0.034          -0.000           0.026          -2.313          -7.230           0.720

Roll from ecliptic north           0.041                          -0.044
Roll from solar north              1.416                          -6.296

Light travel time to Earth (min)           5.474           4.503                   9.883           8.871           5.394

Separation angle with Earth               38.296          32.018                 106.208          94.629          29.279
Separation angle A with B                         70.314

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: Thursday, 03-Apr-2025 01:01:07 UTC
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