Astronomy and Astrophysics – Astrophysics
Scientific paper
2002-01-21
Rev.Mod.Astron. 15 (2002) 133
Astronomy and Astrophysics
Astrophysics
17 pages, 7 figures, to appear in Reviews in Modern Astronomy, 15
Scientific paper
We show that the astrometric Hipparcos data of the stars hosting planet candidates are not accurate enough to yield statistically significant orbits. Therefore, the recent suggestion, based on the analysis of the Hipparcos data, that the orbits of the sample of planet candidates are not randomly oriented in space, is not supported by the data. Assuming random orientation, we derive the mass distribution of the planet candidates and show that it is flat in log M, up to about 10 Jupiter masses. Furthermore, the mass distribution of the planet candidates is well separated from the mass distribution of the low-mass companions by the 'brown-dwarf desert'. This indicates that we have here two distinct populations, one which we identify as the giant planets and the other as stellar secondaries. We compare the period and eccentricity distributions of the two populations and find them surprisingly similar. The period distributions between 10 and 1650 days are flat in log period, indicating a scale-free formation mechanism in both populations. We further show that the eccentricity distributions are similar - both have a density distribution peak at about 0.2-0.4, with some small differences on both ends of the eccentricity range. We present a toy model to mimic both distributions. We found a significant paucity of massive giant planets with short orbital periods. The low frequency of planets is noticeable for masses larger than about 1 Jupiter Mass and periods shorter than 30 days. We point out how, in principle, one can account for this paucity.
Mazeh Tsevi
Zucker Shay
No associations
LandOfFree
A Statistical Analysis of The Extrasolar Planets and The Low-Mass Secondaries does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A Statistical Analysis of The Extrasolar Planets and The Low-Mass Secondaries, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Statistical Analysis of The Extrasolar Planets and The Low-Mass Secondaries will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-12313