Time is plotted along the x axis and the periods during which it is safe to observe this position with GALEX appear as a shaded region on the upper half of the y axis (in yellow). The ratio of the number of eclipses when it is safe to observe this position to the annual number of eclipses on the plot is termed the 'Available Eclipse Ratio'. The value of the available eclipse ratio appears in the plot and is labeled as 'Available Eclipses'. Positions with an available eclipse ratio of < 1% are considered a high planning risk.
The zodiacal light component of the background at this position on the sky appears on the bottom half of the y axis (in green). The time in the visibility window with the largest background (therefore smallest SNR) is shown by the upward pointing arrow (in green) and the time with the smallest background (therefore highest SNR) is shown by the downward pointing arrow (in blue). The diffuse galactic emission remains constant throughout the year and the value is given in a table below the plot.
If a hatch pattern (in green) appears over the shaded region that represents the visibility window, then the total field brightness at this position on the sky may be too high to be safely observed. Consult the brightness checker to verify.
Observation Name: TATOOINES_STAR
Observation Position: RA=92.5266 DEC=47.2743  (J2000)

The visibility report summarizes the visibility and count rate information during the time period shown on the plot. Only NUV count rate information is reported and the values exclude counts from stars, galaxies, and other point source objects in the field of view. Consult the brightness checker for a more complete estimate of the total count rate.
The available eclipse ratio describes the observability of this position relative to the number of eclipses during the time period shown on the plot; a smaller value means fewer eclipses in which the position can be safely observed. The mission planning system (MPS) ratio describes the observability of this position relative to the number of eclipses needed to obtain the requested exposure time; a larger value means more difficult to satisfy and above 100% means the request cannot be satisfied. In general, values > 5% are considered an elevated planning risk and values > 20% are considered a high planning risk.
The zodiacal-light (zodi) figure of merit indicates the relative difference in diffuse-background brightness between "dark time" and "bright time," for periods when the object is visible by GALEX. (For GALEX observations the zodi variation typically has a larger impact than that of the moon.) Generally, zodi variation is relatively insignificant in the SNR of all but low-surface-brightness, extended objects. The zodi figure of merit is typically below 10%, though it can reach above 15%. One can explore the relative zodi contribution to the background using the brightness checker.
Records in table with at least one 'FAIL' are highlighted in pink.
Observation Name: TATOOINES_STAR
Observation Position: RA=92.5266 DEC=47.2743  (J2000)