GROUND-BASED TRANSIT OBSERVATIONS OF THE SUPER-EARTH 55 Cnc e

Improved precision on the radius of the nearby super - Earth 55 Cnc e

We report on new transit photometry for the super-Earth 55 Cnc e obtained with Warm Spitzer/IRAC at 4.5 μm. An individual analysis of these new data leads to a planet radius of 2.21+0.15 −0.16 R⊕, which agrees well with the values previously derived from the MOST and Spitzer transit discovery data. A global analysis of both Spitzer transit time-series improves the precision on the radius of the...

Detection of a transit of the super-Earth 55 Cancri e with warm Spitzer⋆

We report on the detection of a transit of the super-Earth 55 Cnc e with warm Spitzer in IRAC’s 4.5 μm band. Our MCMC analysis includes an extensive modeling of the systematic effects affecting warm Spitzer photometry, and yields a transit depth of 410±63 ppm, which translates to a planetary radius of 2.08 −0.17 R⊕ as measured in IRAC 4.5 μm channel. A planetary mass of 7.81 +0.58 −0.53 M⊕ is d...

Improved precision on the radius of the nearby super - Earth 55

We report on new transit photometry for the super-Earth 55 Cnc e obtained with Warm Spitzer/IRAC at 4.5 μm. An individual analysis of these new data leads to a planet radius of 2.21+0.15 −0.16 R⊕, which agrees well with the values previously derived from the MOST and Spitzer transit discovery data. A global analysis of both Spitzer transit time-series improves the precision on the radius of the...

Stable chaos in the 55 Cnc exoplanetary system ?

The five planets discovered around the main-sequence star 55 Cnc may represent a case of stable chaos. By using both the Frequency Map Analysis and MEGNO we find that about 15 % of the systems that can be build from the nominal orbital elements of the system are highly chaotic. However, in spite of the fast diffusion rate in the phase space, the planetary system is not destabilized over 400 Myr...

Detection Limits in Space-Based Transit Observations