We present a reanalysis of five transit and eight eclipse observations of the ultra-short period super-Earth 55 Cancri e observed using the Spitzer Space Telescope during 2011-2013 .
We use pixel-level decorrelation to derive accurate transit and eclipse depths from the Spitzer data , and we perform an extensive error analysis .
We focus on determining possible variability in the eclipse data , as was reported in Demory et al .
( 14 ) .
From the transit data , we determine updated orbital parameters , yielding T0 = 2455733.0037 \pm 0.0002 , P = 0.7365454 \pm 0.0000003 days , i = 83.5 \pm 1.3 degrees , and R _ { p } = 1.89 \pm 0.05 R _ { \oplus } .
Our transit results are consistent with a constant depth , and we conclude that they are not variable .
We find a significant amount of variability between the eight eclipse observations , and confirm agreement with Demory et al .
( 14 ) through a correlation analysis .
We convert the eclipse measurements to brightness temperatures , and generate and discuss several heuristic models that explain the evolution of the planet ’ s eclipse depth versus time .
The eclipses are best modeled by a year-to-year variability model , but variability on shorter timescales can not be ruled out .
The derived range of brightness temperatures can be achieved by a dark planet with inefficient heat redistribution intermittently covered over a large fraction of the sub-stellar hemisphere by reflective grains , possibly indicating volcanic activity or cloud variability .
This time-variable system should be observable with future space missions , both planned ( JWST ) and proposed ( i.e . ARIEL ) .