Validating 1959 les paul

13 Dec

The radius is determined to be 1.64 Mission, launched in March of 2009, was designed to address the important question of the frequency of Earth-size planets around Sun-like stars, and to characterize extrasolar transiting planets through a 3.5 year program of very precise photometric monitoring of ~156,000 stars (Koch et al. Science results from the mission have already begun to appear (Borucki et al. This is because false positives usually outnumber true planetary systems by a large factor, which is about 10:1 for the most successful surveys from the ground, but is not yet well characterized for team have been summarized by Batalha et al. Spectroscopy is often a crucial step in the vetting process, as it allows not only to measure the mass of a planet but also to examine any changes in the line profiles (bisector spans) that might indicate a false positive (see Queloz et al. However, for faint candidates (14) high-resolution, high signal-to-noise ratio (S/N) spectroscopy becomes prohibitively expensive in terms of telescope time.

Even for brighter candidates, the reflex motion of the star due to an Earth-mass planet can sometimes be below the radial-velocity detection limit, making spectroscopic confirmation very difficult or impossible.

Using together with constraints from other follow-up observations we are able to rule out all blends for the two deeper signals and provide independent validation of their planetary nature.

For the shallower signal, we rule out a large fraction of the false positives that might mimic the transits.

Therefore, it is imperative to take advantage of all the information available in vetting candidates.

With this as our motivation, we describe here the use of the light curves themselves in a different way to help discriminate between true planetary transits and a large variety of possible blend scenarios, on a much more quantitative basis than simple back-of-the-envelope calculations could provide.

For example, blend scenarios involving an eclipsing binary or an eclipsing star–planet pair physically associated with the candidate (hierarchical triple systems) and in a long-period orbit around their common center of mass would often be spatially unresolved from the ground.

It is thus highly desirable to take advantage of this information, particularly since it relies only on observations already in hand.The question then becomes how to validate these candidates, particularly the ones with small planets that are precisely among the most interesting.A number of other tests have been developed that can aid in understanding the nature of the candidate, and that rely on the long-term and nearly continuous photometric monitoring of , as well as the very high astrometric precision achieved in determining the centroids of the stars (see also Steffen et al. These tests include: (1) verifying that alternating events have the same depth, which they may not if the signal is due to a background eclipsing binary; (2) checking for the presence of shallow secondary eclipses, which are common in eclipsing binaries but are not expected for the smallest planets; (3) checking for ellipsoidal variations, which could be another sign of a blend; (4) checking for changes in the centroid positions correlated with the brightness changes, which, if detected, might indicate a blend, or at the very least, a crowded aperture.The photometric aperture of is large enough (typically many arcseconds across) that it usually includes other stars in addition to the candidate, which increases the risk of such blends.In some cases, near-infrared observations with Warm .The idea behind , and is contaminating the light of the candidate.The usually deep eclipses of the binary are attenuated by the light of the candidate, and reduced in depth so that they appear transit-like.This is a powerful diagnostic that is able to disprove many background blends.In addition to these tests, high-resolution imaging is an important tool to identify neighboring stars that might be eclipsing binaries with the potential to cause the transit-like signals.In principle there is an enormous range of possible binary configurations that could mimic all of the features of true planetary transits, including not only their depth, but also the total duration and the length of the ingress and egress phases.Generally, it is only with detailed modeling that these can be ruled out.