Related papers: Is the Interstellar Object 3I/ATLAS Alien Technolo…

The Zoo Hypothesis posits that we have not detected extraterrestrial intelligences (ETIs) because they deliberately prevent us from detecting them. While a valid solution to Fermi's Paradox, it is not particularly amenable to rigorous…

Ultra Fast Astronomy is a new frontier becoming enabled by improved detector technology allowing discovery of optical transients on millisecond to nanosecond time scales. These may reveal counterparts of energetic processes such as fast…

Several recent works have proposed "stellar relay" transmission systems in which a spacecraft at the focus of a star's gravitational lens achieves dramatic boosts in the gain of an outgoing or incoming interstellar transmission. We examine…

We present a multi-wavelength study of the unassociated Fermi-LAT source, 3FGL J0954.8-3948, which is likely the gamma-ray counterpart of a 9.3-hour binary in the field. With more than 9 years of Pass 8 LAT data, we updated the gamma-ray…

We present the concept for STARI: STarlight Acquisition and Reflection toward Interferometry. If launched, STARI will be the first mission to control a 3-D CubeSat formation to the few mm-level, reflect starlight over 10s to 100s of meters…

The recent discovery of the first confirmed Interstellar Objects (ISOs) passing through the Solar System on clearly hyperbolic objects opens the potential for near term ISO missions, either to the two known objects, or to similar objects…

ATLAS (Asteroid Terrestrial Last Alert System) is a time-domain survey using four telescopes, covering the entire sky. It has observed over 10,000 spectroscopically confirmed Type Ia supernovae (SNe~Ia), with thousands of cosmology-grade…

We present case studies of two impulsive solar energetic electron (SEE) events during which particles at energies from 1-600 keV were detected by THEMIS-ARTEMIS orbiting the Moon, Wind at Earth's first Lagrange point, and (for one event)…

With the construction of the VLTI (Very Large Telescope Interferometer of the European Observatory ESO for the southern hemisphere) it is now possible to make observations with resolutions of the order of milli-arc-seconds, especially in IR…

(99942) Apophis is a potentially hazardous asteroid that will closely approach the Earth on April 13, 2029. Although the likelihood of an impact has been ruled out, this close encounter represents a unique opportunity for planetary science…

A recent proposal for the detection of a hypothetical gravitating body 500 AU from the Sun (termed Planet 9) calls for a fleet of near-relativistic spacecraft, equipped with high-precision clocks, to be sent to a region where the object is…

The optimal frequency for interstellar communication, using "Earth 2017" technology, was derived in papers I and II of this series (arXiv:1706.03795, arXiv:1706.05570). The framework included models for the loss of photons from diffraction…

To investigate the feasibility of ancillary target observations with ESA's Ariel mission, we compiled a list of potentially interesting young stars: FUors, systems harbouring extreme debris discs and a larger sample of young stellar objects…

We present high-resolution UVES+VLT observations of neutral nickel and iron atoms in the coma of the interstellar comet 3I/ATLAS taken after perihelion. Metal emission was strong shortly after perihelion and persisted at large heliocentric…

This paper explicates the concept of an Intermediate Point (IP), its incorporation as a node along an interplanetary trajectory, and how it permits the determination and optimization of trajectories to interstellar objects (ISOs). IPs can…

Interstellar objects (ISOs) are small bodies that can travel through our solar system from other star systems. When present in our solar system, they represent an opportunity to study the properties and origins of these objects, as well as…

A body in Solar orbit beyond the Kuiper belt exhibits an annual parallax that exceeds its apparent proper motion by up to many orders of magnitude. Apparent motion of this body along the parallactic ellipse will deflect the angular position…

This paper reports the discovery and orbital characterization of two extreme trans-Neptunian objects (ETNOs), 2016 QV$_{89}$ and 2016 QU$_{89}$, which have orbits that appear similar to that of a previously known object, 2013 UH$_{15}$. All…

Massive stars are of fundamental importance for almost all aspects of astrophysics, but there still exist large gaps in our understanding of their properties and formation because they are rare and therefore distant. It has been found that…

We use an extensive suite of numerical simulations to constrain the mass and orbit of Planet Nine, the recently proposed perturber in a distant eccentric orbit in the outer solar system. We compare our simulations to the observed population…