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MOVES - I. The evolving magnetic field of the planet-hosting star HD189733
Moutou, C.; Vidotto, A. A.; Ehrenreich, D. +9 more
HD189733 is an active K dwarf that is, with its transiting hot Jupiter, among the most studied exoplanetary systems. In this first paper of the Multiwavelength Observations of an eVaporating Exoplanet and its Star (MOVES) programme, we present a 2-yr monitoring of the large-scale magnetic field of HD189733. The magnetic maps are reconstructed for …
HST/COS Observations of Ionized Gas Accretion at the Disk-Halo Interface of M33
Peek, J. E. G.; Zheng, Y.; Putman, M. E. +1 more
We report the detection of accreting ionized gas at the disk-halo interface of the nearby galaxy M33. We analyze Hubble Space Telescope/Cosmic Origins Spectrograph absorption-line spectra of seven ultraviolet-bright stars evenly distributed across the disk of M33. We find Si IV absorption components consistently redshifted relative to the bulk M33…
The Outer Halo of the Milky Way as Probed by RR Lyr Variables from the Palomar Transient Facility
Kulkarni, Shrinivas R.; Laher, Russ R.; Prince, Thomas A. +5 more
RR Lyrae stars are ideal massless tracers that can be used to study the total mass and dark matter content of the outer halo of the Milky Way (MW). This is because they are easy to find in the light-curve databases of large stellar surveys and their distances can be determined with only knowledge of the light curve. We present here a sample of 112…
The Sleeping Monster: NuSTAR Observations of SGR 1806-20, 11 Years After the Giant Flare
Göğüş, Ersin; Kouveliotou, Chryssa; Younes, George +5 more
We report the analysis of five Nuclear Spectroscopic Telescope Array (NuSTAR) observations of SGR 1806-20 spread over a year from 2015 April to 2016 April, more than 11 years following its giant flare (GF) of 2004. The source spin frequency during the NuSTAR observations follows a linear trend with a frequency derivative \dot{ν }=(-1.25+/- 0.03)× …
Multi-instrument observations of the solar eclipse on 20 March 2015 and its effects on the ionosphere over Belgium and Europe
De Keyser, Johan; Berghmans, David; West, Matthew J. +19 more
A total solar eclipse occurred on 20 March 2015, with a totality path passing mostly above the North Atlantic Ocean, which resulted in a partial solar eclipse over Belgium and large parts of Europe. In anticipation of this event, a dedicated observational campaign was set up at the Belgian Solar-Terrestrial Centre of Excellence (STCE). The objecti…
The VMC survey - XXIII. Model fitting of light and radial velocity curves of Small Magellanic Cloud classical Cepheids
Clementini, G.; Ripepi, V.; Molinaro, R. +7 more
We present the results of the χ2 minimization model fitting technique applied to optical and near-infrared photometric and radial velocity data for a sample of nine fundamental and three first overtone classical Cepheids in the Small Magellanic Cloud (SMC). The near-infrared photometry (JK filters) was obtained by the European Southern …
The Scientific Foundations of Forecasting Magnetospheric Space Weather
Eastwood, J. P.; Nakamura, R.; Turc, L. +2 more
The magnetosphere is the lens through which solar space weather phenomena are focused and directed towards the Earth. In particular, the non-linear interaction of the solar wind with the Earth's magnetic field leads to the formation of highly inhomogenous electrical currents in the ionosphere which can ultimately result in damage to and problems w…
Cosmic phylogeny: reconstructing the chemical history of the solar neighbourhood with an evolutionary tree
Jofré, Paula; Das, Payel; Foley, Robert +1 more
Using 17 chemical elements as a proxy for stellar DNA, we present a full phylogenetic study of stars in the solar neighbourhood. This entails applying a clustering technique that is widely used in molecular biology to construct an evolutionary tree from which three branches emerge. These are interpreted as stellar populations that separate in age …
Intrinsic AGN SED & black hole growth in the Palomar-Green quasars
Lani, Caterina; Lutz, Dieter; Netzer, Hagai
We present a new analysis of the Palomar-Green quasar sample based on Spitzer and Herschel observations. (I) Assuming polycyclic aromatic hydrocarbon (PAH)-based star formation luminosities (LSF) similar to Symeonidis et al. (S16), we find mean and median intrinsic active galactic nucleus (AGN) spectral energy distributions (SEDs). Thes…
Swift Observations of SMC X-3 during Its 2016-2017 Super-Eddington Outburst
Wang, Wei; Weng, Shan-Shan; Ge, Ming-Yu +4 more
The Be X-ray pulsar SMC X-3 underwent a giant outburst from 2016 August to 2017 March, which was monitored with the Swift satellite. During the outburst, its broadband flux increased dramatically, and the unabsorbed X-ray luminosity reached an extreme value of ∼ {10}39 erg s-1 around August 24. Using the Swift/XRT data, we me…