The SARS algorithm: detrending CoRoT light curves with Sysrem using simultaneous external parameters

Surveys for exoplanetary transits are usually limited not by photon noise but rather by the amount of red noise in their data. In particular, although the CoRoT spacebased survey data are being carefully scrutinized, significant new sources of systematic noises are still being discovered. Recently, a magnitude-dependant systematic effect was discovered in the CoRoT data by Mazeh & Guterman et al. and a phenomenological correction was proposed. Here we tie the observed effect a particular type of effect, and in the process generalize the popular Sysrem algorithm to include external parameters in a simultaneous solution with the unknown effects. We show that a post-processing scheme based on this algorithm performs well and indeed allows for the detection of new transit-like signals that were not previously detected.Comment: MNRAS accepted. 5 pages, 3 figure

Mass Estimate Of The Moon Phobos From The Radio Science Experiment Mars On Mars-express

International audienceThe mass of the Mars moon Phobos has been estimated several times based on radio tracking data during close flybys by Viking, Phobos-2 and MGS spacecraft. The derived GM values (gravity constant times mass) of the moon Phobos vary considerably between 0.66x10-3 km3/s2 and 0.85x10-3 km3/s2 with a weighted mean value of 0.74±0.06x10-3 km3/s2

Mass Estimate Of The Moon Phobos From The Radio Science Experiment Mars On Mars-express

International audienceThe mass of the Mars moon Phobos has been estimated several times based on radio tracking data during close flybys by Viking, Phobos-2 and MGS spacecraft. The derived GM values (gravity constant times mass) of the moon Phobos vary considerably between 0.66x10-3 km3/s2 and 0.85x10-3 km3/s2 with a weighted mean value of 0.74±0.06x10-3 km3/s2

A new view of Earth's sister: Insights following nine years of Venus Express observations

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A new view of Earth's sister: Insights following nine years of Venus Express observations

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A new view of Earth's sister: Insights following nine years of Venus Express observations

International audienceSince April 2006 ESA’s Venus Express has been performing a global survey of the remarkably dense, cloudy, and dynamic atmosphere of our near neighbour. The mission delivers comprehensive data on the temperature structure, the atmospheric composition, the cloud morphology, the atmospheric dynamics, the solar wind interaction and the escape processes. Vertical profiles of the atmospheric temperature show strong latitudinal trend in the mesosphere and upper troposphere correlated with changes in the cloud top structure and indicate convective instability in the main cloud deck at 50-60 km. Observations reveal significant latitudinal variations and temporal changes in the global cloud top morphology, which modulate the solar energy deposited in the atmosphere. The cloud top altitude varies from 72 km in the low and middle latitudes to 64 km in the polar region, correlated with decrease of the aerosol scale height from 4±1.6 km to 1.7±2.4 km, marking vast polar depression. UV imaging shows for the first time the middle latitudes and polar regions in unprecedented detail. The eye of the Southern polar vortex was found to be a strongly variable feature with complex dynamics. Solar occultation observations and deep atmosphere spectroscopy in spectral transparency windows mapped the distribution of the major trace gases H _{2}O, SO _{2}, CO, COS and their variations above and below the clouds, revealing key features of the dynamical and chemical processes at work. Tracking motions of cloud features provided the most complete characterization of the mean atmospheric circulation as well as its variability. Low and middle latitudes show an almost constant zonal wind speed at the cloud tops and vertical wind shear of 2-3 m/s/km. The zonal wind speed increased from 84±20 m/s to 110±16 m/s over the course of the mission. Towards the pole, the wind speed drops quickly and the vertical shear vanishes. The meridional poleward wind ranges from 0 at equator to about 15 m/s in the middle latitudes. Comparison of the thermal wind field derived from temperature sounding to the cloud-tracked winds confirms the validity of cyclostrophic balance, at least in the latitude range from 30S to 70S. The observations are supported by development of General Circulation Models. Non-LTE infrared emissions in the lines of O _{2}, NO, CO _{2}, OH originating near the mesopause at 95-105 km were detected and mapped. The data show that the peak intensity occurs in average close to the anti-solar point for O _{2} emission, which is consistent with current models of the thermospheric circulation. For almost complete solar cycle the Venus Express instruments continuously monitoring the induced magnetic field and plasma environment established the global escape rates being 3•10 (24) s (-1) , 7•10 (24) s (-1) , 8•10 (22) s (-1) for O (+) , H (+) , and He (+) ions and identified the main acceleration process. For the first time it was shown that the reconnection process takes place in the tail of a non-magnetized body. It was confirmed that the lightning tentatively detected by PVO indeed occurs on Venus. The thermal mapping of the surface in the near-IR spectral “windows” on the night side indicated the presence of recent volcanism on the planet, as do the high and variable SO _{2} abundances

A new view of Earth's sister: Insights following nine years of Venus Express observations

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Expected Performance of the CoRoT Planet Search from Light Curve Beauty Contests

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Expected Performance of the CoRoT Planet Search from Light Curve Beauty Contests

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Expected Performance of the CoRoT Planet Search from Light Curve Beauty Contests

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