Search Publications
The curious case of II Lup: a complex morphology revealed with SAM/NACO and ALMA
Avison, A.; Zijlstra, A. A.; Tuthill, P. G. +5 more
We present the first-ever images of the circumstellar environment of the carbon-rich asymptotic giant branch (AGB) star II Lup in the infrared and sub-mm wavelengths, and the discovery of the envelope's non-spherical morphology with the use of high angular resolution imaging techniques with the sparse aperture masking mode on NACO/Very Large Teles…
Gemini IFU, VLA, and HST observations of the OH megamaser galaxy IRAS F23199+0123: the hidden monster and its outflow
Robinson, Andrew; Baum, Stefi; Storchi-Bergmann, Thaisa +6 more
We present Gemini Multi-Object Spectrograph (GMOS) Integral field Unit (IFU), Very Large Array (VLA), and Hubble Space Telescope (HST) observations of the OH megamaser (OHM) galaxy IRAS F23199+0123. Our observations show that this system is an interacting pair, with two OHM sources associated with the eastern (IRAS 23199E) member. The two members …
Dynamics of Trees of Fragmenting Granules in the Quiet Sun: Hinode/SOT Observations Compared to Numerical Simulation
Roudier, T.; Malherbe, J. -M.; Frank, Z. +1 more
We compare horizontal velocities, vertical magnetic fields, and the evolution of trees of fragmenting granules (TFG, also named families of granules) derived in the quiet Sun at disk center from observations at solar minimum and maximum of the Solar Optical Telescope (SOT on board Hinode) and results of a recent 3D numerical simulation of the magn…
Size Distributions of Solar Proton Events and Their Associated Soft X-Ray Flares: Application of the Maximum Likelihood Estimator
D'Huys, Elke; Cliver, Edward W.
We use the maximum likelihood estimator to determine the slope (α) of the power-law size distribution of the peak proton fluxes of a subsampled set of 106 ∼ 25 MeV solar energetic proton (SEP) events from 1997 to 2016 associated with western hemisphere soft X-ray (SXR) flares: α = 1.28 ± 0.03. For the peak SXR fluxes of a subsample of 110 SEP-asso…
SNhunt151: an explosive event inside a dense cocoon
Drake, A. J.; Djorgovski, S. G.; Geier, S. +20 more
SNhunt151 was initially classified as a supernova (SN) impostor (nonterminal outburst of a massive star). It exhibited a slow increase in luminosity, lasting about 450 d, followed by a major brightening that reaches MV ≈ -18 mag. No source is detected to MV ≳ -13 mag in archival images at the position of SNhunt151 before the …
A Multiline Study of a High-mass Young Stellar Object in the Small Magellanic Cloud with ALMA: The Detection of Methanol Gas at 0.2 Solar Metallicity
Onaka, Takashi; Aikawa, Yuri; Shimonishi, Takashi +5 more
We report the results of subparsec-scale submillimeter observations toward an embedded high-mass young stellar object in the Small Magellanic Cloud (SMC) with ALMA. Complementary infrared data obtained with the AKARI satellite and the Gemini South telescope are also presented. The target infrared point source is spatially resolved into two dense m…
Heating of the solar photosphere during a white-light flare
Kleint, Lucia; Kašparová, Jana; Jurčák, Jan +1 more
Context. The Fe I lines observed by the Hinode/SOT spectropolarimeter were always seen in absorption, apart from the extreme solar limb. Here we analyse a unique dataset capturing these lines in emission during a solar white-light flare.
Aims: We analyse the temperature stratification in the solar photosphere during a white-light flare and co…
Three new barium dwarfs with white dwarf companions: BD+68°1027, RE J0702+129 and BD+80°670
Wang, L.; Zhao, G.; Zhao, J. K. +6 more
We report three new barium (Ba) dwarfs lying in Sirius-like systems. They provide direct evidence that Ba dwarfs are companions to white dwarfs (WDs). Atmospheric parameters, stellar masses and the chemical abundances of 25 elements, including light, α, Fe-peak and s-process elements, are derived from high-resolution and high S/N spectra. The enha…
The Gaia-WISE Extragalactic Astrometric Catalog
Darling, Jeremy; Paine, Jennie; Truebenbach, Alexandra
The Gaia mission has detected a large number of active galactic nuclei (AGNs) and galaxies, but these objects must be identified among the thousandfold more numerous stars. Extant astrometric AGN catalogs do not have the uniform sky coverage required to detect and characterize the all-sky, low-multipole proper motion signals produced by the baryce…
The upcoming mutual event season for the Patroclus-Menoetius Trojan binary
Buie, M. W.; Grundy, W. M.; Noll, K. S. +1 more
We present new Hubble Space Telescope and ground-based Keck observations and new Keplerian orbit solutions for the mutual orbit of binary Jupiter Trojan asteroid (617) Patroclus and Menoetius, targets of NASA's Lucy mission. We predict event times for the upcoming mutual event season, which is anticipated to run from late 2017 through mid 2019.