Search Publications
Realistic gravitational focusing of meteoroid streams
Vida, Denis; Moorhead, Althea V.; Clements, Tiffany D.
The number density and flux of a meteoroid stream is enhanced near a massive body due to the phenomenon known as gravitational focusing. The greatest enhancement occurs directly opposite the massive body from the stream radiant: as an observer approaches this location, the degree of focusing is unbound for a perfectly collimated stream. However, r…
A Random Forest Approach to Identifying Young Stellar Object Candidates in the Lupus Star-forming Region
Melton, Elizabeth
The identification and characterization of stellar members within a star-forming region are critical to many aspects of star formation, including formalization of the initial mass function, circumstellar disk evolution, and star formation history. Previous surveys of the Lupus star-forming region have identified members through infrared excess and…
The GAPS programme at TNG. XXVI. Magnetic activity in M stars: spectroscopic monitoring of AD Leonis
Scandariato, G.; Lanza, A. F.; Maldonado, J. +7 more
Context. Understanding stellar activity in M dwarfs is fundamental to improving our knowledge of the physics of stellar atmospheres and for planet search programmes. High levels of stellar activity (also frequently associated with flare events) can cause additional variations in the stellar emission that contaminate the signal induced by a planet …
Inference of Solar Rotation from Perturbations of Acoustic Mode Eigenfunctions
Roth, Markus; Schad, Ariane
Today's picture of the internal solar rotation rate profile results essentially from helioseismic analyses of frequency splittings of resonant acoustic waves. Here we present another, complementary estimation of the internal solar rotation rate using the perturbation of the shape of the acoustic waves. For this purpose, we extend a global heliosei…
First discovery of an ultra-cool white dwarf benchmark in common proper motion with an M dwarf
Hambly, N. C.; Harvey, E. J.; Lodieu, N. +5 more
Ultra-cool white dwarfs are among the oldest stellar remnants in the Universe. Their efficient gravitational settling and low effective temperatures are responsible for the smooth spectra they exhibit. For that reason, it is not possible to derive their radial velocities or to find the chemistry of the progenitors. The best that can be done is to …
Toward Solving the Puzzle: Dissecting the Complex Merger A521 with Multiwavelength Data
Kim, Jae-Woo; Jee, M. James; Finner, Kyle +3 more
A521 has been a subject of extensive panchromatic studies from X-ray to radio. The cluster possesses a number of remarkable features, including a bright radio relic with a steep spectrum, more than three distinct galaxy groups forming a filament, and two disturbed X-ray peaks at odds with the distant position and tilted orientation of the radio re…
Investigation of ionospheric TEC anomalies caused by space weather conditions
Alcay, Salih; Gungor, Merve
This study examines the influence of space weather conditions on ionospheric TEC variations at different latitudes around the world. According to the space weather condition indices (geomagnetic storm-activity indices, solar activity indices, magnetic field change indices, plasma density and proton flux indices) different time periods were chosen.…
Hubble Space Telescope Snapshot Survey for Resolved Companions of Galactic Cepheids: Final Results
Schaefer, Gail H.; Bond, Howard E.; Evans, Nancy Remage +13 more
Cepheids in multiple systems provide information on the outcome of the formation of massive stars. They can also lead to exotic end-stage objects. This study concludes our survey of 70 galactic Cepheids using the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) with images at two wavelengths to identify companions closer than 5″. In the ent…
Electric sails are potentially more effective than light sails near most stars
Lingam, Manasvi; Loeb, Abraham
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 pressure for F-, G-, K- and M-type stellar systems. We show that electric sails originating near M-dwarfs could att…
Physical characterization of double asteroid (617) Patroclus from 2007/2012 mutual events observations
Colas, F.; Berthier, J.; Pauwels, T. +20 more
We publish a set of 16 light curves of mutual events inside the synchronous system of the Jupiter Trojan (617) Patroclus. Patroclus is th only binary system of the six target asteroids of the forthcoming NASA Discovery-class mission Lucy. Determining the physical parameters of the system is therefore of primary importance in helping to plan the fl…