Related papers: Have mirror planets been observed?
Since the discovery of the first exoplanet we have known that other planetary systems can look quite unlike our own. However, until recently we have only been able to probe the upper range of the planet size distribution. The high precision…
Planetary systems that orbit white dwarf stars can be studied via spectroscopic observations of the stars themselves. Numerous white dwarfs are seen to have accreted mostly rocky minor planets, the remnants of which are present in the…
Are microlensing searches likely to discover planets that harbor life? Given our present state of knowledge, this is a difficult question to answer. We therefore begin by asking a more narrowly focused question: are conditions on planets…
Millisecond pulsars are thought to be neutron stars that have been spun-up by accretion of matter from a binary companion. Although most are in binary systems, some 30% are solitary, and their origin is therefore mysterious. PSR J1719-1438,…
Models are developed to simulate lightcurves of stars dimmed by transiting exoplanets with and without rings. These models are then applied to \textit{Kepler} photometry to search for planetary rings in a sample of 21 exoplanets, mostly hot…
Recent observations indicate that about half of the dwarf satellite galaxies around M31 orbit in a thin plane approximately aligned with the Milky Way. It has been argued that this observation along with several other features can be…
We suggest that the major fraction of binary mergers, which might provide gravitational wave signal detectable by LIGO/Virgo, emerged from the hidden mirror sector. Mirror particles do not interact with an ordinary observer except…
Hundreds of gravitational microlensing events have now been detected towards the Galactic bulge, with many more to come. The detection of fine structure in these events has been theorized to be an excellent way to discover extra-solar…
With more than 260 extrasolar planetary systems discovered to-date, the search for habitable planets has found new grounds. Unlike our solar system, the stars of many of these planets are hosts to eccentric or close-in giant bodies. Several…
During the last couple of years astronomers and astrophysicists have been debating on the fact whether the so called `strange stars' - stars made up of strange quark matter, have been discovered with the candidates like SAX J1808.4-3658, 4U…
With round-the-clock monitoring of galactic bulge microlensing events, the PLANET experiment constrains the abundance and can yield the discovery of planets down to the mass of earth around galactic disk and bulge stars. Data taken until…
We discuss a possible method for detection of dark companions of galactic objects of stellar mass. Such binary systems are likely to occur in the galactic disk and possibly also in the halo. The high incidence of binary and…
We analytically work out the long-term variations caused on the motion of a planet orbiting a star by a very distant, pointlike massive object X. Apart from the semi-major axis a, all the other Keplerian osculating orbital elements…
We used a sample of super-Earth-like planets detected by the Doppler spectroscopy and transit techniques to explore the dependence of orbital parameters of the planets on the metallicity of their host stars. We confirm the previous results…
Observational surveys for extrasolar planets probe the diverse outcomes of planet formation and evolution. These surveys measure the frequency of planets with different masses, sizes, orbital characteristics, and host star properties. Small…
Over the past few decades, a consensus picture has emerged in which roughly a quarter of the universe consists of dark matter. I begin with a review of the observational evidence for the existence of dark matter: rotation curves of…
Detection of Jupiter mass companions to nearby solar type stars with precise radial velocity measurements is now routine, and Doppler surveys are moving towards lower velocity amplitudes. The detection of several Neptune-mass planets with…
Binary systems are a common site of planet formation, despite the destructive effects of the binary on the disk. While surveys of planet forming material have found diminished disk masses around medium separation ($\sim$10--100 au)…
The dependence of gas giant planet occurrence rate on stellar metallicity has been firmly established. We extend this so-called planet-metallicity correlation to broader ranges of metallicities and planet masses/radii. In particular, we…
Small, cool planets represent the typical end-products of planetary formation. Studying the archi- tectures of these systems, measuring planet masses and radii, and observing these planets' atmospheres during transit directly informs…