Unconfirmed/Unpublished Planets Catalogue

We report the results of a synoptic study of the photometric and spectroscopic variability of the classical T Tauri star AA Tau on timescales ranging from a few hours to several weeks. Emission lines show both infall and outflow signatures and are well reproduced by magnetospheric accretion models with moderate mass accretion rates and high inclinations. The veiling shows variations that indicate the presence of 2 rotationally modulated hot spots corresponding to the two magnetosphere poles. It correlates well with the HeI line flux, with B-V and the V excess flux. We have indications of a time delay between the main emission lines and veiling, the lines formed farther away preceding the veiling changes. The time delay we measure is consistent with accreted material propagating downwards the accretion columns at free fall velocity from a distance of about 8 Rstar. We also report periodic radial velocity variations of the photospheric spectrum which might point to the existence of a 0.02 Msun object orbiting the star at a distance of 0.08 AU. During a few days, the variability of the system was strongly reduced and the line fluxes and veiling severely depressed. We argue that this episode of quiescence corresponds to the temporary disruption of the magnetic configuration at the disk inner edge. The radial velocity variations of inflow and outflow diagnostics in the Halpha profile yield further evidence for large scale variations of the magnetic configuration on a timescale of a month. These results may provide the first clear evidence for large scale instabilities developping in T Tauri magnetospheres as the magnetic field lines are twisted by differential rotation between the star and the inner disk.

Previously, we have assembled data on the binary star system 44i Bootis, collected by our group and others over nearly a century, concerning the timing of its primary eclipses. These have been previously modeled by an ephemeris equation, assuming a constant orbital period. We have previously shown that the system is slowing down a uniform rate. We present data demonstrating a small sinusoidal trend in the remaining differences between eclipse time observations and calculations (an O-C diagram). We sought to model the cause of this variation by the gravitational interaction of a planet orbiting the binary star pair. Such a planet would necessarily be a brown dwarf of 0.0475 solar masses, with a semi-major axis of 10.729 AU. We are examining the stability of such an orbit. We also present initial data for the binary star system VW Cephei.

The Cornell High-order Adaptive Optics Survey for brown dwarfs (CHAOS), currently about 90% complete, uses the Palomar Hale Telescope's adaptive optics system to survey 80 bright stars out to 13 parsecs. Using the telescope's AO Science camera, brown dwarf companions 4-200 AU can be identified using coronagraphic imaging and spectroscopic modes. We will be using monte carlo simulations to create population models consistent with the CHAOS data set.Currently, we have observed 70 systems out of a target sample of 80. Five candidate companions await follow-up observations. As of now, no systems in the target sample have shown strong evidence of having brown dwarf companions. These early results support previous speculations of a ``brown dwarf desert'' at orbital separations out to 200 AU.While the target sources revealed no evidence of brown dwarf companions, accompanying observations of calibration stars provided evidence of an early methane dwarf candidate around the binary system HD150451AB. Forty seven parsecs from earth, the candidate indicated a projected orbital separation of 280 AU.

We present strong evidence of an early-type methane brown dwarf companion to the binary system HD150451AB. We obtained J-band and K-band diffraction-limited images with the Palomar Adaptive Optics system (PALAO) and the PHARO camera on the Hale 5-meter telescope, revealing an object having infrared colors and luminosities consistent with an early-type T-dwarf. We also obtained high-resolution astrometry over two years, showing common proper motion and confirming the object as a true physical companion. We used differential methane band imaging with the Palomar Wide-field Infrared Camera (WIRC) to reveal methane absorption, confirming the T-dwarf nature of the object. We observed apparent variability in the methane depression with ~{50%} amplitude over a ~{72}-hour timescale. After Gliese 229B and Gliese 570D, HD150451C is only the third known methane binary companion to a normal star.

In this contribution we report evidence for a planetary companion around a young and active late-type K star. Our group has been developing a study of stellar activity and kinematics for this star over the past years. Previous results show a high level of stellar activity, with the presence of prominence-like structures, spots on surface and strong flare events. Radial velocity (RV) variations with a semi-amplitude of up to 1 km s^-1 were detected. When the nature of these variations were investigated it was found that they are not due to stellar activity. Based upon the analysis of bisector velocity span, as well as Ca II H & K emission, we report that the best explanation for RV variation is the presence of a sub-stellar companion. The Keplerian fit of the RV data yields an orbital solution for a close-in massive planet with an orbital period of 7.783 days. Also, the presence of this close-in massive planet chould be an interpretation for the high level of stellar activity detected.

Up to now our knowledge on frequency of planets of stars that are more massive than the sun is rather limited. In here we present the discovery of a planet orbiting the F4V-F6V star 30 Ari B, which is also a member of a hierarchical triple-star system.