Search Publications
Weighing the Galactic disk in sub-regions of the solar neighbourhood using Gaia DR2
Monari, G.; de Salas, P. F.; Widmark, A.
Aims: We infer the gravitational potential of the Galactic disk by analysing the phase-space densities of 120 stellar samples in 40 spatially separate sub-regions of the solar neighbourhood, using Gaia's second data release (DR2), in order to quantify spatially dependent systematic effects that bias this type of measurement.
Methods: The…
Giant Outer Transiting Exoplanet Mass (GOT 'EM) Survey. II. Discovery of a Failed Hot Jupiter on a 2.7 Yr, Highly Eccentric Orbit
Esposito, Thomas M.; Kane, Stephen R.; Rosenthal, Lee J. +13 more
Radial velocity (RV) surveys have discovered giant exoplanets on au-scale orbits with a broad distribution of eccentricities. Those with the most eccentric orbits are valuable laboratories for testing theories of high-eccentricity migration. However, few such exoplanets transit their host stars, thus removing the ability to apply constraints on fo…
Discovery of a Candidate Hypervelocity Star Originating from the Sagittarius Dwarf Spheroidal Galaxy
Huang, Yang; Chang, Jiang; Zhang, Huawei +5 more
In this Letter, we report the discovery of an intriguing hypervelocity star (HVS; J1443+1453) candidate that is probably from the Sagittarius Dwarf Spheroidal galaxy (Sgr dSph). The star is an old and very metal-poor low-mass main-sequence turn-off star (age ∼14.0 Gyr and [Fe/H] = -2.23 dex) and has a total velocity of ${559.01}_{-87.40}^{+135.07}…
High-frequency Wave Power Observed in the Solar Chromosphere with IBIS and ALMA
Kowalski, Adam F.; Cranmer, Steven R.; Reardon, Kevin P. +3 more
We present observational constraints on the chromospheric heating contribution from acoustic waves with frequencies between 5 and 50 mHz. We use observations from the Dunn Solar Telescope in New Mexico, complemented with observations from the Atacama Large Millimeter Array collected on 2017 April 23. The properties of the power spectra of the vari…
Discovery of 40.5 ks Hard X-Ray Pulse-phase Modulations from SGR 1900+14
Suzuki, H.; Enoto, T.; Makishima, K. +4 more
X-ray timing properties of the magnetar SGR 1900+14 were studied, using the data taken with Suzaku in 2009 and NuSTAR in 2016, for a time lapse of 114 and 242 ks, respectively. On both occasions, the object exhibited the characteristic two-component spectrum. The soft component, dominant in energies below ~5 keV, showed a regular pulsation, with a…
The Pulsating White Dwarf G117-B15A: Still the Most Stable Optical Clock Known
Kepler, S. O.; Hermes, J. J.; Bell, Keaton J. +14 more
The pulsating hydrogen atmosphere white dwarf star G 117-B15A has been observed since 1974. Its main pulsation period at 215.19738823(63) s, observed in optical light curves, varies by only (5.12 ± 0.82) × 10-15 s s-1 and shows no glitches, as pulsars do. The observed rate of period change corresponds to a change of the pulsa…
The Breakthrough Listen Search for Intelligent Life: MeerKAT Target Selection
de Pater, Imke; DeBoer, David; Gajjar, Vishal +18 more
New radio telescope arrays offer unique opportunities for large-scale commensal SETI surveys. Ethernet-based architectures are allowing multiple users to access telescope data simultaneously by means of multicast Ethernet subscriptions. Breakthrough Listen will take advantage of this by conducting a commensal SETI survey on the MeerKAT radio teles…
Variable stars in the VVV globular clusters. II. NGC 6441, NGC 6569, NGC 6626 (M 28), NGC 6656 (M 22), 2MASS-GC 02, and Terzan 10
Carballo-Bello, Julio A.; Smith, Leigh C.; Minniti, Dante +18 more
Context. The Galactic globular clusters (GGCs) located in the inner regions of the Milky Way suffer from high extinction that makes their observation challenging. High densities of field stars in their surroundings complicate their study even more. The VISTA Variables in the Via Lactea (VVV) survey provides a way to explore these GGCs in the near-…
(6478) Gault: physical characterization of an active main-belt asteroid
Skiff, Brian A.; Rivet, Jean-Pierre; Bendjoya, Philippe +22 more
In 2018 December, the main-belt asteroid (6478) Gault was reported to display activity. Gault is an asteroid belonging to the Phocaea dynamical family and was not previously known to be active, nor was any other member of the Phocaea family. In this work, we present the results of photometric and spectroscopic observations that commenced soon afte…
Precision Millimeter Astrometry of the α Centauri AB System
Kervella, Pierre; Beichman, Charles; Benedict, G. Fritz +2 more
Alpha Centauri A is the closest solar-type star to the Sun and offers the best opportunity to find and ultimately to characterize an Earth-sized planet located in its habitable zone. Here, we describe initial results from an Atacama Large Millimeter/submillimeter Array (ALMA) program to search for planets in the α Cen AB system using differential …