Search Publications
Storms or systematics? The changing secondary eclipse depth of WASP-12b
de Mooij, Ernst J. W.; Gibson, Neale P.; Watson, Christopher A. +4 more
WASP-12b is one of the most well-studied transiting exoplanets, as its highly inflated radius and its 1.1 d orbit around a G0-type star make it an excellent target for atmospheric categorization through observation during its secondary eclipse. We present two new secondary eclipse observations of WASP-12b, acquired an year apart with the Wide Fiel…
The second-degree gravity coefficients of Phobos from two Mars Express flybys
Pätzold, M.; Hahn, M.; Andert, T. +6 more
Several close spacecraft flybys of Phobos have been performed over the past 40 yr in order to determine the gravity field of this tiny Martian moon. In this work, the second-degree coefficients of the gravity field of Phobos were derived from the radio tracking data of two combined Mars Express flybys (2010 and 2013), by applying a least squares r…
On the emergence of THOUSANDS of absorption lines in the quasar PG 1411+442: a clumpy high-column density outflow from the broad emission-line region?
Tripp, Todd M.; Hamann, Fred; Veilleux, Sylvain +1 more
Quasar outflows are fundamental components of quasar environments that might play an important role in feedback to galaxy evolution. We report on the emergence of a remarkable new outflow absorption-line system in the quasar PG1411+442 (redshift ∼0.089) detected in the UV and visible with the Hubble Space Telescope Cosmic Origins Spectrograph and …
Discovery of the first resolved triple white dwarf
Hermes, J. J.; Gänsicke, B. T.; Tremblay, P. -E. +4 more
We report the discovery of J1953-1019, the first resolved triple white dwarf system. The triplet consists of an inner white dwarf binary and a wider companion. Using Gaia DR2 photometry and astrometry combined with our follow-up spectroscopy, we derive effective temperatures, surface gravities, masses, and cooling ages of the three components. All…
A new line on the wide binary test of gravity
Banik, Indranil
The relative velocity distribution of wide binary (WB) stars is sensitive to the law of gravity at the low accelerations typical of galactic outskirts. I consider the feasibility of this wide binary test using the `line velocity' method. This involves considering only the velocity components along the direction within the sky plane orthogonal to t…
Ultraluminous X-ray sources with flat-topped noise and QPO
Fabrika, Sergei; Atapin, Kirill; Caballero-García, Maria D.
We analysed the X-ray power density spectra of five ultraluminous X-ray sources (ULXs) NGC 5408 X-1, NGC 6946 X-1, M 82 X-1, NGC 1313 X-1, and IC 342 X-1 that are the only ULXs that display both flat-topped noise (FTN) and quasi-periodic oscillations (QPOs). We studied the QPO frequencies, fractional root-mean-square (rms) variability, X-ray lumin…
Particle acceleration in the Herbig-Haro objects HH 80 and HH 81
Carrasco-González, Carlos; Vig, Sarita; González-Martín, Omaira +4 more
We present an analysis of radio (Karl G. Jansky Very Large Array (VLA)), optical (Hubble Space Telescope (HST)), and X-ray (Chandra and XMM-Newton) observations and archival data of the Herbig-Haro objects HH 80 and HH 81 in the context of jet-cloud interactions. Our radio images are the highest angular resolution to date of these objects, allowin…
Characterization of the precision premium in astrometry
Lin, F. R.; Peng, Q. Y.; Zheng, Z. J. +1 more
The precision premium, a concept in astrometry that was first presented by Pascu in 1994, initially means that the relative positional measurement of the Galilean satellites of Jupiter will be more accurate when their separations are small. Correspondingly, many observations have been obtained of these Galilean satellites since it was introduced. …
Bow shocks, bow waves, and dust waves - III. Diagnostics
Henney, William J.; Arthur, S. J.
Stellar bow shocks, bow waves, and dust waves all result from the action of a star's wind and radiation pressure on a stream of dusty plasma that flows past it. The dust in these bows emits prominently at mid-infrared wavelengths in the range 8 to 60 µm. We propose a novel diagnostic method, the τ-η diagram, for analysing these bows, which i…
Using Gaia DR2 to detect extratidal structures around the Galactic globular cluster NGC 362
Carballo-Bello, Julio A.
We explore the possibility of searching for extratidal features around the Galactic globular cluster NGC 362 using the Gaia DR2 (second data release) together with a modified version of a classical statistical decontamination algorithm. Our results suggest that an important stellar component is associated with this globular cluster, which is perfe…