Search Publications
Nova LMC 2009a as observed with XMM-Newton, compared with other novae
Ness, Jan-Uwe; Behar, Ehud; Pinto, Ciro +9 more
We examine four high-resolution reflection grating spectrometers (RGS) spectra of the February 2009 outburst of the luminous recurrent nova LMC 2009a. They were very complex and rich in intricate absorption and emission features. The continuum was consistent with a dominant component originating in the atmosphere of a shell burning white dwarf (WD…
Population-based identification of H α-excess sources in the Gaia DR2 and IPHAS catalogues
Maccarone, T. J.; Court, J. M. C.; Knigge, C. +8 more
We present a catalogue of point-like H α-excess sources in the Northern Galactic Plane. Our catalogue is created using a new technique that leverages astrometric and photomeric information from Gaia to select H α-bright outliers in the INT Photometric H α Survey of the Northern Galactic Plane (IPHAS), across the colour-absolute magnitude diagram. …
Space observations of AA Doradus provide consistent mass determinations. New HW-Vir systems observed with TESS
Heber, U.; Irrgang, A.; Reed, M. D. +5 more
We present an overview of eclipsing systems of the HW-Virginis (HW-Vir) type, based on space observations from the Transiting Exoplanet Survey Satellite (TESS) mission. We perform a detailed analysis of the properties of AA Doradus (AA Dor), which was monitored for almost a full year. This excellent time series data set permitted us to search for …
Effect of orbital trapping by bar resonances in the local U-V velocity field
Fernández-Trincado, José G.; Moreno, Edmundo; Chaves-Velasquez, Leonardo +2 more
The effects in the local U-V velocity field due to orbital trapping by bar resonances have been studied computing 15 resonant families in a non-axisymmetric Galactic potential, considering the bar's angular velocity between 35 and 57.5 ${\rm \, km\, s^{-1}{kpc}^{-1}}$. Only cases in the low, 37.5, 40 ${\rm \, km\, s^{-1}{kpc}^{-1}}$, and high, 55,…
A universal relationship between stellar masses and binding energies of galaxies
Chen, Yanmei; Mao, Shude; Shi, Yong +3 more
In this study, we demonstrate that stellar masses of galaxies (Mstar) are universally correlated through a double power-law function with the product of the dynamical velocities (Ve) and sizes to one-fourth power ($R_{\rm e}^{0.25}$) of galaxies, both measured at the effective radii. The product $V_{\rm e}R_{\rm e}^{0.25}$ re…
Long-term measurements of the erosion and accretion of dust deposits on comet 67P/Churyumov-Gerasimenko with the OSIRIS instrument
Sierks, H.; Fulle, M.; Güttler, C. +10 more
We monitor the seasonal erosion and accretion of dust deposits in the Imhotep, Hatmehit, and Ma'at regions of comet 67P/Churyumov-Gerasimenko with OSIRIS Narrow Angle Camera images. The vertical accuracy of such measurements is 0.2 m and the spatial scale of the images we used is lower than 0.60 m pixel-1. We calculate the height of 21 …
Effects of solar flares and coronal mass ejections on Earth's horizontal magnetic field and solar wind parameters during the minimum solar cycle 24
Yoshikawa, A.; Syed Zafar, S. N. A.; Umar, R. +3 more
Previous studies have reported that coronal mass ejections (CMEs) and solar flares lead to the development of huge storms and high-speed streams. Our aim in this paper is to investigate the response of the geomagnetic index SYM/H to the solar wind parameters, such as solar wind speed V, dynamic pressure P, input energy IE and the interplanetary ma…
Characteristics of source locations and solar cycle distribution of the strong solar proton events (≥1000 pfu) from 1976 to 2018
Le, Gui-Ming; Zhao, Ming-Xian; Qi-Li +3 more
We studied the source locations and solar cycle distribution of strong solar proton events (SPEs, ≥1000 pfu) measured at the Earth from 1976 to 2018. There were 43 strong SPEs during this period. 27.9 per cent of the strong SPEs were ground level enhancement (GLE) events. We detect more strong SPEs coming from the Western hemisphere. The strong SP…
Unveiling short-period binaries in the inner VVV bulge
Minniti, D.; Contreras Ramos, R.; Saito, R. K. +5 more
Most of our knowledge of the structure of the Milky Way has come from the study of variable stars. Among these variables, mimicking the periodic variation of pulsating stars, are eclipsing binaries. These stars are important in astrophysics because they allow us to directly measure the radii and masses of the components, as well as the distance to…
A spectroscopically confirmed Gaia-selected sample of 318 new young stars within ∼200 pc
Zhou, George; Nordlander, Thomas; Žerjal, Maruša +7 more
In the Gaia era, the majority of stars in the Solar neighbourhood have parallaxes and proper motions precisely determined while spectroscopic age indicators are still missing for a large fraction of low-mass young stars. In this work, we select 756 overluminous late K and early M young star candidates in the southern sky and observe them over 64 n…