Record photometric precision ground based telescopes

Ground Based Detection of Transiting Hot Earths
Christopher J. Burke1
1 Harvard CFA
Extrasolar planets that transit bright stars provide the opportunity to measure highly accurate planet radii and to detect and characterize planetary atmospheres outside the solar system. Transit and radial velocity surveys continue to push the envelope toward finding smaller planets. Is it possible to take advantage of the large primary mirrors on ground-based telescopes to detect or follow up Earth-sized transiting planets? I present results from an 8 night observing run on the WIYN 3.5m that surveyed the Hot Jupiter transiting planet stellar host XO-2 for an additional Earth-sized transiting planet. The achieved photometric precision is 250ppm/min on this V=11.2 star and is nearly at the scintillation, Poisson, and read noise limits. Based upon these results I will briefly discuss some limitations of the observations along with some possibilities for improvement. These observations do provide optimism that larger aperture ground based telescopes are not limited to discovery and follow up of Hot Earths orbiting M dwarf hosts, but can be extended to Hot Earth’s orbiting bright solar type hosts as well.

We present photometry of WASP-10 during the transit of its short-period Jovian planet. We employed the novel PSF-shaping capabilities the OPTIC camera mounted on the UH 2.2m telescope to achieve a photometric precision of 4.7e-4 per 1.3 min sample. With this new light curve, in conjunction with stellar evolutionary models, we improve on existing measurements of the planetary, stellar and orbital parameters. We find a stellar radius Rstar = 0.698 +/- 0.012 Rsun and a planetary radius Rp = 1.080 +/- 0.020 Rjup. The quoted errors do not include any possible systematic errors in the stellar evolutionary models. Our measurement improves the precision of the planet's radius by a factor of 4, and revises the previous estimate downward by 16% (2.5sigma, where sigma is the quadrature sum of the respective confidence limits). Our measured radius of WASP-10b is consistent with previously published theoretical radii for irradiated Jovian planets.

Sirius_Alpha wrote:Oh I remember that. There's an Oklo.org post on it. From way back when.