Search Publications
The phenomenon of shape evolution from solar-driven outgassing for analogues of small Kuiper belt objects
Rezac, L.; Li, J. -Y.; Zhao, Y. +1 more
One of the key findings of the Rosetta mission to the Jupiter-family comet 67P/Churyumov-Gerasimenko was its peculiar bi-lobed shape and its apparent Northern/Southern hemispheric dichotomy in large-scale morphology. This has re-ignited scientific discussions on the topic of the origin, evolution and age of the nucleus. In this work, we conduct a …
Onthe changes in the physical properties of the ionized region around the Weigelt structures in η Carinae over the 5.54-yr spectroscopic cycle
Gull, T. R.; Corcoran, M. F.; Hillier, D. J. +3 more
We present HST/STIS observations and analysis of two prominent nebular structures around the central source of η Carinae, the knots C and D. The former is brighter than the latter for emission lines from intermediate- or high-ionization potential ions. The brightness of lines from intermediate- and high-ionization potential ions significantly decr…
Pulsation in the white dwarf HE 1017-1352: confirmation of the class of hot DAV stars
Kepler, S. O.; Romero, Alejandra D.; Antunes Amaral, L. +3 more
We report the detection of periodic variations on the $T_\mathrm{eff}\simeq 32\, 000$ K DA white dwarf star HE 1017-1352. We obtained time series photometry using the 4.1-m Southern Astrophysical Research telescope on three separate nights for a total of 16.8 h. From the frequency analysis, we found four periods of 605, 556, 508, and 869 s with si…
A low-mass stellar companion to the young variable star RZ Psc
Henning, Thomas; Ménard, François; Kral, Quentin +10 more
RZ Psc is a young Sun-like star with a bright and warm infrared excess that is occasionally dimmed significantly by circumstellar dust structures. Optical depth arguments suggest that the dimming events do not probe a typical sightline through the circumstellar dust, and are instead caused by structures that appear above an optically thick mid-pla…
Luminous blue variable candidates in M31
Vinokurov, A.; Solovyeva, Y.; Bizyaev, D. +7 more
We study five luminous blue variable (LBV) candidates in the Andromeda galaxy and one more (MN112) in the Milky Way. We obtain the same-epoch near-infrared (NIR) and optical spectra on the 3.5-m telescope at the Apache Point Observatory and on the 6-m telescope of the SAO RAS. The candidates show typical LBV features in their spectra: broad and st…
Searching for eclipsing binaries in the area of RA: 02h21m36s, Dec: +57○11'32″
Li, Kai; Gao, Xing; Sun, Guo-You +5 more
By analysing the data observed by the Comet Search Programme telescope at Xingming Observatory from 2018 October 11 to 2018 December 19, 24 eclipsing binaries were identified. By cross-matching with the VSX (AAVSO) website, we found that four binaries are newly discovered. By analysing the Transiting Exoplanet Survey Satellite (TESS) data, the lig…
Kinematics of main-sequence stars from the Gaia DR2 and PMA proper motions
Akhmetov, V. S.; Fedorov, P. N.; Velichko, Anna B.
We aim at analysis of kinematics of main-sequence stars from the GaiaDR2 and PMA catalogues as well as comparison of kinematic parameters derived from their proper motions. We decompose the stellar velocity field on to a set of vector spherical harmonics (VSH), and, using the relations between the decomposition coefficients and the Ogorodnikov-Mil…
AStroLens: automatic strong-lens modelling of X-ray selected galaxy clusters
Ebeling, Harald; Zalesky, Lukas
We use AStroLens, a newly developed gravitational lens-modelling code that relies only on geometric and photometric information of cluster galaxies as input, to map the strong-lensing regions and estimate the lensing strength of 96 galaxy clusters at z = 0.5-0.9. All clusters were identified during the extended Massive Cluster Survey (eMACS) based…
A Swift view of X-ray and UV radiation in the planet-forming T Tauri system PDS 70
Güdel, Manuel; Pye, John P.; Page, Kim L. +4 more
PDS 70 is a ∼5-Myr-old star with a gas and dust disc in which several protoplanets have been discovered. We present the first ultraviolet (UV) detection of the system along with X-ray observations taken with the Neil Gehrels Swift Observatory satellite. PDS 70 has an X-ray flux of 3.4 × 10-13 erg cm-2 s-1 in the 0.…
Structural parameters for the globular-cluster-like objects in NGC 1052-DF2
Zou, Hu; Nie, Jundan; Zhang, Tianmeng +8 more
Recently, van Dokkum et al. have found an ultra-diffuse galaxy NGC 1052-DF2 with little or no dark matter, based on a spectroscopic study of its 11 constituent globular-cluster-like objects. In this paper, we analyse these 11 objects using Hubble Space Telescope imaging. We derive the structural parameters for each object by fitting the surface br…