Related papers: Have mirror planets been observed?
Models of terrestrial planet formation in the presence of a migrating giant planet have challenged the notion that hot-Jupiter systems lack terrestrial planets. We briefly review this issue and suggest that hot-Jupiter systems should be…
The first extrasolar planets were discovered serendipitously, by finding the slight variation in otherwise highly regular timing of the pulses, caused by the planets orbiting a millisecond pulsar. In analogy with the Solar system planets,…
Kepler has identified over 600 multiplanet systems, many of which have several planets with orbital distances smaller than that of Mercury -- quite different from the Solar System. Because these systems may be difficult to explain in the…
We present the lightcurves of two microlensing events from the MACHO Project data that are likely to be due to lenses with masses similar to Jupiter's mass. Although the MACHO Project survey data are not sufficient to definitively establish…
Small planets, 1-4x the size of Earth, are extremely common around Sun-like stars, and surprisingly so, as they are missing in our solar system. Recent detections have yielded enough information about this class of exoplanets to begin…
To date, nearly two hundred planet-forming disks have been imaged with high resolution. Our propensity to study bright and extended objects is however biasing our view of the disk demography. In this work, we contribute to alleviate this…
Observations of circumstellar disks around stars as a function of stellar properties such as mass, metallicity, multiplicity, and age, provide constraints on theories concerning the formation and evolution of planetary systems. Utilizing…
Recent analyses have shown that distant orbits within the scattered disk population of the Kuiper belt exhibit an unexpected clustering in their respective arguments of perihelion. While several hypotheses have been put forward to explain…
We report precise Doppler measurements of GJ317 (M3.5V) that reveal the presence of a planet with a minimum mass Msini = 1.2 Mjup in an eccentric, 692.9 day orbit. GJ317 is only the third M dwarf with a Doppler-detected Jovian planet. The…
Studies have shown that remnants of destroyed planets and debris-disk planetesimals can survive the volatile evolution of their host stars into white dwarfs, but detection of intact planetary bodies around white dwarfs are few. Simulations…
For centuries, our knowledge of planetary systems and ideas about planet formation were based on a single example, our solar system. During the last thirteen years, the discovery of ~170 planetary systems has ushered in a new era for…
We have detected a 12 M$_{\rm Jup}$ planet orbiting in or near the habitable zone of a main-sequence A star via the pulsational phase shifts induced by orbital motion. The planet has an orbital period of $840\pm20$ d and an eccentricity of…
Two decades ago, astronomers began detecting planets orbiting stars other than our Sun, so-called exoplanets. Since that time, the rate of detections and the sensitivity to ever-smaller planets has improved dramatically with several…
We explore two ways in which objects of planetary masses can form. One is in disk systems like the solar system. The other is in dense clusters where stars and brown dwarfs form. We do not yet have the instrumental accuracy to detect…
Stars and planets are the fundamental objects of the Universe. Their formation processes, though related, may differ in important ways. Stars almost certainly form from gravitational collapse and probably have formed this way since the…
We have gathered a sample of 112 main-sequence stars with known debris disks. We collected published information and performed adaptive optics observations at Lick Observatory to determine if these debris disks are associated with binary or…
To date, several exoplanets have been discovered orbiting stars with close binary companions (a~<30 AU). The fact that planets can form in these dynamically challenging environments implies that planet formation must be a robust process.…
Discovering other worlds the size of our own has been a long-held dream of astronomers. The transiting planets Kepler-20e and Kepler-20f, which belong to a multi-planet system, hold a very special place among the many groundbreaking…
Doppler planet searches revealed that many giant planets orbit close to their host star or in highly eccentric orbits. These and subsequent observations inspired new theories of planet formation that invoke gravitation interactions in…
Rings are ubiquitous around giant planets in our Solar System. They evolve jointly with the nearby satellite system. They could form either during the giant planet formation process or much later, as a result of large scale dynamical…