Related papers: Mass Limit on Nemesis
We have searched for planetary companions around 800 pulsars monitored at the Jodrell Bank Observatory, with both circular and eccentric orbits of periods between $20$ days and $17$ years and inclination-dependent planetary masses from…
We present numerical simulations of the interaction between a collimated, bipolar ``pulse'' ejected from a star and a continuous wind ejected from a stellar companion. We explore the characteristics of the predicted H$\alpha$ intensity maps…
Almost all massive stars are part of a binary system. Given the wide range of separations at which these companions are found, several observational techniques have been adopted to characterize them, but contrasts greater than 4 in the…
We present the PLANET photometric data set for \ob14, a high magnification ($A_{\rm max}\sim 16$) event alerted by the OGLE collaboration toward the Galactic bulge in 1998. The PLANET data set consists a total of 461 I-band and 139 $V-$band…
Polaris, the nearest and brightest classical Cepheid, is a member of at least a triple system. It has a wide ($18''$) physical companion, the F-type dwarf Polaris B. Polaris itself is a single-lined spectroscopic binary with an orbital…
Stars which pass close to the Sun can perturb the Oort cloud, injecting comets into the inner solar system where they may collide with the Earth. Using van Leeuwen's re-reduction of the Hipparcos data complemented by the original Hipparcos…
A moderately massive early Sun has been proposed to resolve the so-called faint early Sun paradox. We calculate the time-evolution of the solar mass that would be required by this hypothesis, using a simple parametrized energy-balance model…
Based on Gaia DR2 data and new CHIRON radial velocities, we have discovered that two nearby stellar associations UPK 535 (318.08 $\pm$ 0.29 pc, $25^{+15}_{-10}$ Myr, 174 stars) and Yep 3 (339.54 $\pm$ 0.25 pc , $45^{+55}_{-20}$ Myr, 297…
We present the discovery of a 0.2" companion to the young M dwarf GJ 3629 as part of our high contrast adaptive optics imaging search for giant planets around low-mass stars with the Keck-II and Subaru telescopes. Two epochs of imaging…
The mass-luminosity relation for late-type stars has long been a critical tool for estimating stellar masses. However, there is growing need for both a higher-precision relation and a better understanding of systematic effects (e.g.,…
We improve, using a larger set of observations including Voyager 2 Neptune flyby data, previous bounds on the amount of dark matter (DM) trapped in a spherically symmetric distribution about the sun. We bound DM by noting that such a…
The relationship between luminosity and mass is of fundamental importance for direct imaging studies of brown dwarf and planetary companions to stars. In principle this can be inferred from theoretical mass-luminosity models; however, these…
Doppler measurements of the M4 dwarf star, Gliese 876, taken at both Lick and Keck Observatory reveal periodic, Keplerian velocity variations with a period of 61 days. The orbital fit implies that the companion has a mass of, M = 2.1 MJUP…
We present new high-contrast images in near-infrared wavelengths ($\lambda$ = 1.04, 1.24, 1.62, 2.18 and 3.78$\mu$m) of the young variable star CQ Tau, aiming to constrain the presence of companions in the protoplanetary disc. We reached a…
XMASS, a low-background, large liquid-xenon detector, was used to search for solar axions that would be produced by bremsstrahlung and Compton effects in the Sun. With an exposure of 5.6ton days of liquid xenon, the model-independent limit…
We report the detection of seven low mass companions to intermediate-mass stars (SpT B/A/F; $M$$\approx$1.5-4.5 solar masses) in the Scorpius-Centaurus Association using nonredundant aperture masking interferometry. Our newly detected…
We present the analysis of OGLE-2014-BLG-1760, a planetary system in the galactic bulge. We combine Keck Adaptive Optics follow-up observations in $K$-band with re-reduced light curve data to confirm the source and lens star identifications…
We use 7 years of electron and positron Fermi-LAT data to search for a possible excess in the direction of the Sun in the energy range from 42 GeV to 2 TeV. In the absence of a positive signal we derive flux upper limits which we use to…
Why does the Sun have a radius around 696000~km? We will see in this article that dimensional arguments can be used to understand the size of the Sun and of a few other things along the way. These arguments are not new and can be found…
We present an H-band image of the companion of Chi 1 Orionis taken with the Keck adaptive optic system and NIRC2 camera equipped with a 300mas-diameter coronographic mask. The direct detection of this companion star enables us to calculate…