We present high-precision radial velocity observations of WASP-17 throughout the transit of its close-in giant planet, using the MIKE spectrograph on the 6.5m Magellan Telescope at Las Campanas Observatory. By modeling the Rossiter-McLaughlin effect,
we find the sky-projected spin-orbit angle to be lambda = 167.4 pm 11.2 deg. This independently confirms the previous finding that WASP-17b is on a retrograde orbit, suggesting it underwent migration via a mechanism other than just the gravitational interaction between the planet and the disk. Interestingly, our result for lambda differs by 45 pm 13 deg from the previously announced value, and we also find that the spectroscopic transit occurs 15 pm 5 min earlier than expected, based on the published ephemeris. The discrepancy in the ephemeris highlights the need for contemporaneous spectroscopic and photometric transit observations whenever possible.
SuperLupus is a deep transit survey monitoring a Galactic Plane field in the Southern hemisphere. The project is building on the successful Lupus Survey, and will double the number of images of the field from 1700 to 3400, making it one of the longes
t duration deep transit surveys. The immediate motivation for this expansion is to search for longer period transiting planets (5-8 days) and smaller radii planets. It will also provide near complete recovery for the shorter period planets (1-3 days). In March, April, and May 2008 we obtained the new images and work is currently in progress reducing these new data.
We present a strong case for a transiting Hot Jupiter planet identified during a single-field transit survey towards the Lupus Galactic plane. The object, Lupus-TR-3b, transits a V=17.4 K1V host star every 3.91405d. Spectroscopy and stellar colors in
dicate a host star with effective temperature 5000 +/- 150K, with a stellar mass and radius of 0.87 +/- 0.04M_sun and 0.82 +/- 0.05R_sun, respectively. Limb-darkened transit fitting yields a companion radius of 0.89 +/- 0.07R_J and an orbital inclination of 88.3 +1.3/-0.8 deg. Magellan 6.5m MIKE radial velocity measurements reveal a 2.4 sigma K=114 +/- 25m/s sinusoidal variation in phase with the transit ephemeris. The resulting mass is 0.81 +/- 0.18M_J and density 1.4 +/- 0.4g/cm^3. Y-band PANIC image deconvolution reveal a V>=21 red neighbor 0.4 away which, although highly unlikely, we cannot conclusively rule out as a blended binary with current data. However, blend simulations show that only the most unusual binary system can reproduce our observations. This object is very likely a planet, detected from a highly efficient observational strategy. Lupus-TR-3b constitutes the faintest ground-based detection to date, and one of the lowest mass Hot Jupiters known.
We have conducted a wide-field photometric survey in a single 52x52 field towards the Lupus Galactic Plane in an effort to detect transiting Hot Jupiter planets. The planet Lupus-TR-3b was identified from this work. The dataset also led to the detect
ion of 494 field variables, all of which are new discoveries. This paper presents an overview of the project, along with the total catalog of variables, which comprises 190 eclipsing binaries (of contact, semi-contact and detached configurations), 51 miscellaneous pulsators of various types, 237 long period variables (P>=2d), 11 delta Scuti stars, 4 field RR Lyrae (3 disk and 1 halo) and 1 irregular variable. Our survey provides a complete catalog of W UMa eclipsing binaries in the field to V=18.8, which display a Gaussian period distribution of 0.277+/-0.036d. Several binary systems are likely composed of equal mass M-dwarf components and others display evidence of mass transfer. We find 17 candidate blue stragglers and one binary that has the shortest period known, 0.2009d (V=20.9). The frequency of eclipsing binaries (all types) is found to be 1.7+/-0.4x10^{-3} per star, substantially higher (by a factor of 3-10) than previously determined in the haloes of the globular clusters 47 Tuc and omega Cen. This indicates that cluster dynamics aids mass segregation and binary destruction.
