Search for giant planets in M67

Search for giant planets in M67 I. Overview

Attempting to find giant planets using the radial velocity method in the solar-age open cluster M67. The cluster is known to contain several candidate solar twins. From this survey, 11 stars are candidates for hosting substellar objects.

Search for giant planets in M67 IV: survey results
https://arxiv.org/abs/1703.04296

Quote :

We present the results of a seven-year-long radial velocity survey of a sample of 88 main-sequence and evolved stars to reveal signatures of Jupiter-mass planets in the solar-age and solar-metallicity open cluster M67. We aim at studying the frequency of giant planets in this cluster with respect to the field stars. In addition, our sample is also ideal to perform a long-term study to compare the chemical composition of stars with and without giant planets in detail. We analyzed precise radial velocity (RV) measurements obtained with five different instruments. We conducted Monte Carlo simulations to estimate the occurrence rate of giant planets in our radial velocity survey. All the planets previously announced in this RV campaign with their properties are summarized here: 3 hot Jupiters around the main-sequence stars YBP1194, YBP1514, and YBP401, and 1 giant planet around the evolved star S364. Two additional planet candidates around the stars YBP778 and S978 are also analyzed in the present work. We discuss stars that exhibit large RV variability or trends individually. For 2 additional stars, long-term trends are compatible with new binary candidates or substellar objects, which increases the total number of binary candidates detected in our campaign to 14. Based on the Doppler-detected planets discovered in this survey, we find an occurrence of giant planets of ~18.0%(+12.0/-8.0%) in the selected period-mass range. This frequency is slightly higher but consistent within the errors with the estimate for the field stars, which leads to the general conclusion that open cluster and field statistics agree. However, we find that the rate of hot Jupiters in the cluster (~5.7%(+5.5/-3.0%)) is substantially higher than in the field.

Don't we already have a thread for the first few planets from the survey? I'm having a hard time finding it.

Huh, I was sure we had a thread like that...

Of the two new ones listed in the abstract, YBP778 seems to be quite uncertain, while SAND978 ends up being a more secure candidate: 511-day orbital period with low-to-moderate eccentricity around a red giant.

Also interesting to see that the hot Jupiters are in eccentric orbits.