Related papers: Deceleration of high-velocity interstellar photon …
A search for laser light from the directions of Alpha Centauri A and B was performed by examining 15362 optical, high-resolution spectra obtained between 2004 and 2018. None of the spectra exhibit laser emission lines. The threshold was 10%…
We analyze the evolution of the potentially habitable planet Proxima Centauri b to identify environmental factors that affect its long-term habitability. We consider physical processes acting on size scales ranging from the galactic to the…
We present differential radial velocity measurements of Proxima Centauri collected over 4 years with the ESO CES with a mean precision of $54 ms^{-1}$. We find no evidence of a periodic signal that could corroborate the existence of a…
We evaluate the achievable maximum energy of nuclei diffusively accelerated by shock wave in the jet of Cen A, based on an updated model involving the stochastic magnetic fields that are responsible for recent synchrotron X-ray…
Radial velocity monitoring has found the signature of a $M \sin i = 1.3$~M$_\oplus$ planet located within the Habitable Zone (HZ) of Proxima Centauri \citep{Anglada16}. Despite a hotter past and an active host star the planet Proxima~b…
Over the past five years, radial-velocity and transit techniques have revealed a new population of Earth-like planets with masses of a few Earth masses. Their very close orbit around their host star requires an exquisite inner working angle…
The solar gravitational lens (SGL) provides a factor of $10^{11}$ amplification for viewing distant point sources beyond our solar system. As such, it may be used for resolved imaging of extended sources, such as exoplanets, not possible…
I review those properties of the interstellar medium within 15 light-years of the Sun which will be relevant for the planning of future rapid ($v /ge 0.1c$) interstellar space missions to the nearest stars. As the detailed properties of the…
The scientific interest in directly image and identifying Earth-like planets within the Habitable Zone (HZ) around nearby stars is driving the design of specialized direct imaging mission such as ACESAT, EXO-C, EXO-S and AFTA-C. The inner…
The solar gravitational lens (SGL) offers unique capabilities for high-resolution imaging of faint, distant objects, such as exoplanets. In the near future, a spacecraft carrying a meter-class telescope with a solar coronagraph would be…
We perform long-term simulations, up to ten billion years, of closely-spaced configurations of 2 -- 6 planets, each as massive as the Earth, traveling on nested orbits about either stellar component in $\alpha$ Centauri AB. The innermost…
We study H I Lyman-alpha absorption observed by the Hubble Space Telescope toward the nearby binary system Alpha Cen (G2 V+K0 V) and its distant companion star Proxima Cen (M5.5 Ve). Absorption from heliospheric H I heated by the solar…
The VVV survey has observed the southern disk of the Milky Way in the near infrared, covering 240 deg$^{2}$ in the $ZYJHK_S$ filters. We search the VVV Survey images in a $\sim$19 deg$^{2}$ field around $\alpha$ Centauri, the nearest…
In this paper we outline the considerations required in order to select a target star system for the Icarus interstellar mission. It is considered that the maximum likely range for the Icarus vehicle will be 15 light-years, and a list is…
Projections for the earliest interstellar mission possibilities are calculated based on 27 years of data on historic energy trends, societal priorities, required mission energy, and the implications of the Incessant Obsolescence Postulate…
We report the detection of a large-scale magnetic field at the surface of the slowly-rotating fully-convective M dwarf Proxima Centauri. Ten circular polarization spectra, collected from April to July 2017 with the HARPS-Pol…
Many astronomers have speculated that the solar system contains undiscovered massive planets or a distant stellar companion. The acceleration of the solar system barycenter can constrain the mass and position of the putative companion. In…
Electric sails are propulsion systems that generate momentum via the deflection of stellar wind particles through electric forces. Here, we investigate the relative merits of electric sails and light sails driven by stellar radiation…
The scenario and efficiency of water transport by icy asteroids and comets are still amongst the most important unresolved questions of planetary systems. A better understanding of cometary dynamics in extrasolar systems shall provide…
The light from a source at a distance d will arrive at detectors separated by 100 AU at times that differ by as much as 120 (d/100 Mpc)^{-1} nanoseconds because of the curvature of the wavefront. At gigahertz frequencies, the arrival time…