Related papers: Have mirror planets been observed?
We ask if Earth-like planets (terrestrial mass and habitable-zone orbit) can be detected in multi-planet systems, using astrometric and radial velocity observations. We report here the preliminary results of double-blind calculations…
We detect a cold, terrestrial planet in a binary-star system using gravitational microlensing. The planet has low mass (2 Earth masses) and lies projected at $a_{\perp,ph}$ ~ 0.8 astronomical units (AU) from its host star, similar to the…
We report precise Doppler measurements of GJ849 (M3.5V) that reveal the presence of a planet with a minimum mass of 0.82 Mjup in a 5.16 year orbit. At a = 2.35 AU, GJ849b is the first Doppler-detected planet discovered around an M dwarf to…
Giant planets orbiting stars other than the Sun are clearly detectable through precise radial-velocity measurements of the orbital reflex motion of the parent star. In the four years since the discovery of the companion to the star 51 Peg,…
Imaging of planets is very difficult, due to the glare from their nearby, much brighter suns. Static and slowly-evolving aberrations are the limiting factors, even after application of adaptive optics. The residual speckle pattern is highly…
Strange stars ought to exist in the universe according to the strange quark matter hypothesis, which states that matter made of roughly equal numbers of up, down, and strange quarks could be the true ground state of baryonic matter rather…
We still do not understand how planets form, or why extra-solar planetary systems are so different from our own solar system. But the last few years have dramatically changed our view of the discs of gas and dust around young stars.…
Sahu et al. recently reported tentative evidence for a large population of "free-floating" planetary-mass objects in a nearby globular cluster. If verified, this discovery is consistent with a prediction that the galactic dark matter has a…
The majority of stars form in star clusters and many are thought to have planetary companions. We demonstrate that multi-planet systems are prone to instabilities as a result of frequent stellar encounters in these star clusters much more…
We present new fast numerical simulations of cosmic microwave background and large scale structure in the case in which the cosmological dark matter is made entirely or partly of mirror matter. We consider scalar adiabatic primordial…
In the Solar system the planets' compositions vary with orbital distance, with rocky planets in close orbits and lower-density gas giants in wider orbits. The detection of close-in giant planets around other stars was the first clue that…
We calculate simulated images of disks perturbed by embedded small planets. These 10-50 M_Earth bodies represent the growing cores of giant planets. We examine scattered light and thermal emission from these disks over a range of…
Radial velocity surveys suggest that the Solar System may be unusual and that Jupiter-like planets have a frequency <20% around solar-type stars. However, they may be much more common in one of the closest associations in the solar…
We use Monte Carlo simulations to estimate the number of extrasolar planets that are directly detectable in the solar-neighborhood using current and forthcoming high-contrast imaging instruments. Our calculations take into account the…
The possibility that mirror matter with masses in the several hundred GeV- TeV range exists is explored. Mirror matter appears quite naturally in many unified models of particle interactions both in GUTs and in strings often in vector-like…
The prospects for the habitability of M-dwarf planets have long been debated, due to key differences between the unique stellar and planetary environments around these low-mass stars, as compared to hotter, more luminous Sun-like stars.…
Moderately close binaries are a special class of targets for planet searches. From a theoretical standpoint, their hospitality to giant planets is uncertain and debated. From an observational standpoint, many of these systems present…
Jupiter and Saturn have extended, nearly toroidal atmospheres composed of material ejected from their moons or rings. Here we suggest that similar atmospheres must exist around giant extrasolar planets and might be observable in a transit…
Recent ground and space-based observations show that stars with multiple planets are common in the galaxy. Most of these observational methods are biased toward detecting large planets near to their host stars. Because of these…
Among the numerous known extrasolar planets, only a handful have been imaged directly so far, at large orbital radii and in rather evolved systems. The Atacama Large Millimeter/submillimeter Array (ALMA) will have the capacity to observe…