Search Publications
Nondetection of Helium in the Upper Atmospheres of Three Sub-Neptune Exoplanets
Désert, Jean-Michel; Mansfield, Megan; Kasper, David +5 more
We present a search for helium in the upper atmospheres of three sub-Neptune-sized planets to investigate the origins of these ubiquitous objects. The detection of helium for a low-density planet would be strong evidence for the presence of a primary atmosphere accreted from the protoplanetary nebula because large amounts of helium are not expecte…
Are inner disc misalignments common? ALMA reveals an isotropic outer disc inclination distribution for young dipper stars
Tazzari, M.; Williams, J. P.; Ansdell, M. +12 more
Dippers are a common class of young variable star exhibiting day-long dimmings with depths of up to several tens of per cent. A standard explanation is that dippers host nearly edge-on (Id ≈ 70°) protoplanetary discs that allow close-in (<1 au) dust lifted slightly out of the mid-plane to partially occult the star. The identification…
Varstrometry for Off-nucleus and Dual Subkiloparsec AGN (VODKA): Methodology and Initial Results with Gaia DR2
Shen, Yue; Hwang, Hsiang-Chih; Liu, Xin +1 more
Gaia’s precision astrometry allows systematic identification of optically selected subkiloparsec dual active galactic nuclei (AGNs), off-nucleus AGNs, and small-scale lensed quasars by “varstrometry”—where variability-induced astrometric jitter, I.e., temporal displacements of photocenter in unresolved sources, can be reasonably well detected or c…
Globular clusters in the inner Galaxy classified from dynamical orbital criteria
Barbuy, Beatriz; Bica, Eduardo; Pérez-Villegas, Angeles +3 more
Globular clusters (GCs) are the most ancient stellar systems in the Milky Way. Therefore, they play a key role in the understanding of the early chemical and dynamical evolution of our Galaxy. Around 40 per cent of them are placed within ∼4 kpc from the Galactic centre. In that region, all Galactic components overlap, making their disentanglement …
Cluster Difference Imaging Photometric Survey. II. TOI 837: A Young Validated Planet in IC 2602
Barbieri, M.; Henning, T.; Winn, J. N. +42 more
We report the discovery of TOI 837b and its validation as a transiting planet. We characterize the system using data from the NASA Transiting Exoplanet Survey Satellite mission, the ESA Gaia mission, ground-based photometry from El Sauce and ASTEP400, and spectroscopy from CHIRON, FEROS, and Veloce. We find that TOI 837 is a T = 9.9 mag G0/F9 dwar…
Three Lyα Emitting Galaxies within a Quasar Proximity Zone at z ∼ 5.8
Ellis, Richard S.; Bosman, Sarah E. I.; Meyer, Romain A. +3 more
Quasar proximity zones at $z\gt 5.5$ correspond to overdense and overionized environments. Galaxies found inside proximity zones can therefore display features that would otherwise be masked by absorption in the intergalactic medium. We demonstrate the utility of this quasar-galaxy synergy by reporting the discovery of the first three "proximate L…
The GALAH survey: multiple stars and our Galaxy. I. A comprehensive method for deriving properties of FGK binary stars
Munari, U.; Wittenmyer, R. A.; Stello, D. +24 more
Context. Binary stellar systems form a large fraction of the Galaxy's stars. They are useful as laboratories for studying the physical processes taking place within stars, and must be correctly taken into account when observations of stars are used to study the structure and evolution of the Galaxy. The advent of large-scale spectroscopic and phot…
Ghostly galaxies as solitons of Bose-Einstein dark matter
Broadhurst, Tom; Smoot, George F.; De Martino, Ivan +2 more
The large dark cores of common dwarf galaxies are unexplained by the standard heavy particle interpretation of dark matter. This puzzle is exacerbated by the discovery of a very large but barely visible, dark matter dominated galaxy Antlia II orbiting the Milky Way, uncovered by tracking star motions with the Ĝaia satellite. Although Antlia II has…
The Strength of the Dynamical Spiral Perturbation in the Galactic Disk
Hogg, David W.; Rix, Hans-Walter; Buck, Tobias +4 more
The mean Galactocentric radial velocities $\langle {v}_{R}\rangle (R,\varphi )$ of luminous red giant stars within the midplane of the Milky Way reveal a spiral signature, which could plausibly reflect the response to a nonaxisymmetric perturbation of the gravitational potential in the Galactic disk. We apply a simple steady-state toy model of a l…
ICME Evolution in the Inner Heliosphere
Luhmann, J. G.; Jian, L. K.; Gopalswamy, N. +1 more
ICMEs (interplanetary coronal mass ejections), the heliospheric counterparts of what is observed with coronagraphs at the Sun as CMEs, have been the subject of intense interest since their close association with geomagnetic storms was established in the 1980s. These major interplanetary plasma and magnetic field transients, often preceded and acco…