Search Publications
Imaging Evidence for Solar Wind Outflows Originating from a Coronal Mass Ejection Footpoint
Golub, Leon; Aulanier, Guillaume; Schmieder, Brigitte +2 more
We report on Atmospheric Imaging Assembly observations of plasma outflows originating in a coronal dimming during a 2015 April 28 filament eruption. After the filament started to erupt, two flare ribbons formed, one of which had a well-visible hook enclosing a core (twin) dimming region. Along multiple funnels located in this dimming, a motion of …
The RR Lyrae projected density distribution from the Galactic centre to the halo
Minniti, Dante; Ripepi, Vincenzo; Alonso-García, Javier +4 more
The projected density distribution of type ab RR Lyrae (RRab) stars was characterised from the innermost regions of the Milky Way to the halo, with the aim of placing constraints on the Galaxy's evolution. The compiled sample (NRRab = 64 850) stems from fundamental mode RR Lyrae variables identified by the VVV, OGLE, and Gaia surveys. T…
Galactic Potential and Dark Matter Density from Angular Stellar Accelerations
Buschmann, Malte; Safdi, Benjamin R.; Schutz, Katelin
We present an approach to measure the Milky Way (MW) potential using the angular accelerations of stars in aggregate as measured by astrometric surveys like Gaia. Accelerations directly probe the gradient of the MW potential, as opposed to indirect methods using, e.g., stellar velocities. We show that end-of-mission Gaia stellar acceleration data …
The first photometric and spectroscopic analysis of the extremely low mass-ratio contact binary NSVS 5029961
Li, Kai; Xia, Qi-Qi; Zheng, Shu-Yue
We performed photometric and spectroscopic investigations of NSVS 5029961 for the first time. The new BV(RI)c-band light curves were obtained with the 1.0-m telescope at Weihai Observatory of Shandong University. Applying the Wilson-Devinney program, we found that NSVS 5029961 is an A-subtype shallow contact binary with extremely low ma…
Radio and optical observations of the possible AE Aqr twin, LAMOST J024048.51+195226.9
Knigge, C.; Heywood, I.; Hewitt, D. M. +8 more
It was recently proposed that the cataclysmic variable (CV) LAMOST J024048.51+195226.9 may be a twin to the unique magnetic propeller system AE Aqr. If this is the case, two predictions are that it should display a short period white dwarf spin modulation, and that it should be a bright radio source. We obtained follow-up optical and radio observa…
The TESS View of LOFAR Radio-emitting Stars
Pope, Benjamin J. S.; Günther, Maximilian N.; Ansdell, Megan +4 more
The recent detection of the M dwarf GJ 1151 at 144 MHz low radio frequencies using LOFAR has been interpreted as evidence of an exoplanet magnetically interacting with its host star. This would be the first exoplanet detected around a main-sequence star by a radio telescope. Radial velocity confirmation of such a planet has proven inconclusive and…
A ΔR ∼ 9.5 mag Superflare of an Ultracool Star Detected by the SVOM/GWAC System
Xu, Y.; Huang, L.; Wang, J. +21 more
We report the detection and follow-up of a superstellar flare GWAC 181229A with an amplitude of ΔR ∼ 9.5 mag on an M9-type star by SVOM/GWAC and the dedicated follow-up telescopes. The estimated bolometric energy Ebol is (5.56-9.25) × 1034 erg, which makes the event one of the most powerful flares seen on ultracool stars. The…
Identifying Bound Stellar Companions to Kepler Exoplanet Host Stars Using Speckle Imaging
Howell, Steve B.; Everett, Mark E.; Horch, Elliott P. +4 more
The Kepler mission and subsequent ground-based follow-up observations have revealed a number of exoplanet host stars with nearby stellar companions. This study presents speckle observations of 57 Kepler objects of interest (KOIs) that are also double stars, each observed over a 3-8 yr period, which has allowed us to track their relative motions wi…
The Fornax3D project: Planetary nebulae catalogue and independent distance measurements to Fornax cluster galaxies
Viaene, S.; Morelli, L.; Pinna, F. +17 more
Extragalactic planetary nebulae (PNe) offer a way to determine the distance to their host galaxies thanks to the nearly universal shape of the planetary nebulae luminosity function (PNLF). Accurate PNe distance measurements rely on obtaining well-sampled PNLFs and the number of observed PNe scales with the encompassed stellar mass. This means eith…
Exploring the Galactic Anticenter Substructure with LAMOST and Gaia DR2
Tian, Hao; Zhao, Gang; Wu, Yaqian +12 more
We characterize the kinematic and chemical properties of 589 Galactic anticenter substructure stars (GASS) with K/M giants in integrals-of-motion space. These stars likely include members of previously identified substructures such as Monoceros, A13, and the Triangulum-Andromeda cloud. We show that these stars are in nearly circular orbits on both…