candidates faq

Our candidates table contains information for 124 known extrasolar planets. We strive to keep this table up to date as new planets are discovered, and as the orbital determinations of existing planets improve. If you notice any planetary parameters that are out of date, please contact laughlin at sign ucolick period org.

the candidates table

1. Planet-bearing stars are listed in the candidates table by their most commonly used name. For further information on the listed stars, including exact coordinates, spectral type, space motion, and alternate names, query the SIMBAD astronomical database maintained by the Centre de Donnees astronomiques de Strasbourg (CDS). For finding charts and evaluation of the comparison star situation of each star, we recommend the Goddard SkyView Virtual Telescope.

2. We follow the usual convention and label planets with "b", "c", "d", etc. in order of their discovery, rather than in order of their distance from the parent star. GJ 876 "b", for example, has a period of ~60 days, which is twice as long as the ~30 day period of GJ 876 "c". Planetary orbital data have been taken from the discovery papers, or in some cases, the updated websites of the discoverers. The table is based on the following source data files for planetary orbital elements and parent stellar properties. We are currently in the process of adding detailed information regarding the bibliographic source of each orbital parameter. If you notice any orbital parameters that appear to be outdated or incorrect, please contact Greg Laughlin at: laughlin at sign ucolick period org. Planetary radii are calculated using the evolution models given in Bodenheimer, Laughlin and Lin (2003). In every case, we assume that the giant planets contain solid cores, and do not have extra sources of interior heat.

3. Planetary periods are listed with four significant digits. In some cases, periods are known to considerably higher accuracy. The period of the transiting planet HD 209458 b, for example, is now determined to be P=3.52474541 days, with an uncertainty of only 0.00000025 days (Wittenmyer, 2004, unpublished Masters thesis, SDSU).

4. The "P" column gives the geometric probability that the planet can be observed in transit. This probability is given by equation (1) of Seagroves et al 2003. The values for the eccentricity, argument of perihelion, and stellar radius used to compute the probabilities are found by clicking on the planet's entry in the "Planet" column (column 2). Important: For planets such as HD 209458 b and TrES-1, which are known to transit, the true probability that transits can be observed is unity, whereas for planets which are known not to transit (such as 51 Peg b) the true probability is zero.

5,6 Right Ascension and Declinations are given for each planets. For exact coordinates, one should query SIMBAD with the name of the parent star.

7. The estimated transit depth is based on (RPlanet)2/(RStar)2, and does not take limb darkening into account.

8. Transit time predictions are based on the predicted midpoint moment of a central transit, and are computed using the orbital data listed in the entries of column 2.

9. The window flag indicates whether the planet is currently within our definition of the "transit window". The transit window is currently defined as the interval between NT(P-dP)-dTPeri-TDuration/2 and NT(P+dP)+dTPeri+TDuration/2. We are currently working on code to make

Monte Carlo estimates of the transit windows based on a Markov Chain Monte Carlo procedure.

10. Ephemeris tables are computed based on Keplerian orbits, using this Fortran source listing. The Fortran code is run once per day at 1:00 AM Pacific Time. The Fortran source writes HTML code to automatically update the Master table and all associated Ephemeris files.

11.We list all transit photometry checks of which we are aware. This includes sources cited in the literature, in addition to observations made by transitsearch members. If you have information to update this column, please send it to laughlin at sign ucolick period org.