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Distributions of gas and small and large grains in the LkHα 330 disk trace a young planetary system
Zhu, Z.; Ginski, C.; Rosotti, G. +13 more
Planets that are forming around young stars are expected to leave clear imprints in the distribution of the gas and dust of their parental protoplanetary disks. In this paper, we present new scattered light and millimeter observations of the protoplanetary disk around LkHα 330, using SPHERE/VLT and ALMA, respectively. The scattered-light SPHERE ob…
A CHEOPS-enhanced view of the HD 3167 system
Alonso, R.; Deleuil, M.; Erikson, A. +92 more
Much remains to be understood about the nature of exoplanets smaller than Neptune, most of which have been discovered in compact multi-planet systems. With its inner ultra-short period planet b aligned with the star and two larger outer planets d-c on polar orbits, the multi-planet system HD 3167 features a peculiar architecture and offers the pos…
1RXH J082623.6-505741: A New Long-period Cataclysmic Variable with an Evolved Donor and a Low Mass-transfer Rate
Strader, Jay; Bahramian, Arash; Chomiuk, Laura +13 more
We report the discovery of 1RXH J082623.6-505741, a 10.4 hr orbital period compact binary. Modeling extensive optical photometry and spectroscopy reveals a ~0.4 M ⊙ K-type secondary transferring mass through a low-state accretion disk to a nonmagnetic ~0.8 M ⊙ white dwarf. The secondary is overluminous for its mass and domina…
The Emptiness Inside: Finding Gaps, Valleys, and Lacunae with Geometric Data Analysis
Hogg, David W.; Peek, Joshua E. G.; Hunt, Jason A. S. +2 more
Discoveries of gaps in data have been important in astrophysics. For example, there are kinematic gaps opened by resonances in dynamical systems, or exoplanets of a certain radius that are empirically rare. A gap in a data set is a kind of anomaly, but in an unusual sense: instead of being a single outlier data point, situated far from other data …
Quantifying kinematic substructure in star-forming regions with statistical tests of spatial autocorrelation
Parker, Richard J.; Wright, Nicholas J.; Arnold, Becky
We investigate whether spatial-kinematic substructure in young star-forming regions can be quantified using Moran's I statistic. Its presence in young star clusters would provide an indication that the system formed from initially substructured conditions, as expected by the hierarchical model of star cluster formation, even if the cluster were sp…
Solar and interplanetary events that drove two CIR-related geomagnetic storms of 1 June 2013 and 7 October 2015, and their ionospheric responses at the American and African equatorial ionization Anomaly regions
Akala, A. O.; Amaechi, P. O.; Simi, K. G. +3 more
This study investigates the sequence of solar and interplanetary events that drove the 1 June 2013 and October 2015 geomagnetic storms and how the American (68°-78oE) and African (32°-42oE) Equatorial Ionization Anomaly (EIA) regions responded to them. We constructed the EIA structures by using Total Electron Content (TEC) an…
The Host Galaxy of the Recoiling Black Hole Candidate in 3C 186: An Old Major Merger Remnant at the Center of a z = 1 Cluster
Bianchi, S.; Macchetto, F. D.; Capetti, A. +10 more
3C 186, a radio-loud quasar at z = 1.0685, was previously reported to have both velocity and spatial offsets from its host galaxy, and has been considered as a promising candidate for a gravitational wave recoiling black hole triggered by a black hole merger. Another possible scenario is that 3C 186 is in an ongoing galaxy merger, exhibiting a tem…
A Close-in Puffy Neptune with Hidden Friends: The Enigma of TOI 620
Bieryla, Allyson; Latham, David W.; Quinn, Samuel N. +82 more
We present the validation of a transiting low-density exoplanet orbiting the M2.5 dwarf TOI 620 discovered by the NASA Transiting Exoplanet Survey Satellite (TESS) mission. We utilize photometric data from both TESS and ground-based follow-up observations to validate the ephemerides of the 5.09 day transiting signal and vet false-positive scenario…
The Origin of the Unfocused XMM-Newton Background, Its Variability, and Lessons Learned for ATHENA
Tiengo, Andrea; De Luca, Andrea; Marelli, Martino +7 more
We analyzed the unexposed to the sky (outFOV) region of the MOS2 detector on board XMM-Newton covering 15 yr of data amounting to 255 Ms. We show convincing evidence that the origin of the unfocused background in XMM-Newton is due to energetic protons, electrons, and hard X-ray photons. Galactic cosmic rays are the main contributors as shown by th…
Backscattered Solar Lyman-α Emission as a Tool for the Heliospheric Boundary Exploration
Bertaux, Jean-Loup; Lallement, Rosine; Quémerais, Eric +4 more
This review summarizes our current understanding of the outer heliosphere and local interstellar medium (LISM) inferred from observations and modeling of interplanetary Lyman-α emission. The emission is produced by solar Lyman-α photons (121.567 nm) backscattered by interstellar H atoms inflowing to the heliosphere from the LISM. Studies of Lyman-…