| OBJ_CENT_DX | float | Estimated guide star shift in X using centroid method | pixel |
| OBJ_CENT_DY | float | Estimated guide star shift in X using centroid method | pixel |
| OBJ_CORR_DX | float | Estimated guide star shift in X using correlation method | pixel |
| OBJ_CORR_DY | float | Estimated guide star shift in X using correlation method | pixel |
| OBJ_CORR_ERRX | float | Error on estimated X shift using correlation method | pixel |
| OBJ_CORR_ERRY | float | Error on estimated Y shift using correlation method | pixel |
| OBJ_FLAG | int | Bitwise flag related to the guide star. Each bit is explained in the code | |
| OBJ_FLUX | float | The measured flux of the guide star | ADU |
| OBJ_FWHM | float | The estimated FWHM of the guide star | pixel |
| obj_nr | int | The guide star number | |
| OBJ_SKY_BCKG | float | Estimated background for guide star | ADU |
| OBJ_X | float | The x position of the guide star | |
| OBJ_Y | float | The y position of the guide star | |
| OFFSET_DEC | float | Estimated shift in DEC | arcsec |
| OFFSET_FLAG | int | Bitwise flag related to the control loop. Each bit is explained in the code | |
| OFFSET_RA | float | Estimated shift in RA | arcsec |
| row_nr | int | The guide star row number in the fits table | |
| TIME | datetime | The time the source was measured | |
