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Spectroscopic observations of flares and superflares on AU Mic
Heinzel, P.; Guenther, E. W.; Skarka, M. +13 more
The young active flare star AU Mic is the planet host star with the highest flare rate from Transiting Exoplanet Survey Satellite data. Therefore, it represents an ideal target for dedicated ground-based monitoring campaigns with the aim to characterize its numerous flares spectroscopically. We performed such spectroscopic monitoring with the ESO1…
NGTS-31b and NGTS-32b: two inflated hot Jupiters orbiting subgiant stars
Ramsay, Gavin; Wheatley, Peter J.; Bayliss, Daniel +38 more
We present the discoveries of NGTS-31b(= TOI-2721), and NGTS-32b, two hot Jupiters from the Next Generation Transit Survey (NGTS) transiting slightly evolved stars. The orbital periods, radii, and masses are 4.16 and 3.31 d, 1.61 and 1.42
Connection between steep radio spectral slopes and dust extinction in QSOs: evidence for outflow-driven shocks in dusty QSOs
Alexander, D. M.; Rosario, D. J.; Morabito, L. K. +9 more
Recent studies have found a striking positive correlation between the amount of dust obscuration and enhanced radio emission in quasi-stellar objects (QSOs). However, what causes this connection remains unclear. In this paper we analyse uGMRT Band-3 (400 MHz) and Band-4 (650 MHz) data of a sample of 38 1.0 < z < 1.5 QSOs with existing high-r…
On the progenitor of the Crab Pulsar
Kochanek, C. S.; Cruz-Cruz, Elvira
We investigate the progenitor of the Crab supernova by examining the remnant's surrounding stellar population. The Crab is interesting because of the apparently low energy and mass of the supernova remnant. We also know it was not a binary at death and that the explosion formed a neutron star. Using Gaia EDR3 parallaxes and photometry, we analyse …
Photometric and spectroscopic studies of six W UMa-type eclipsing binaries
Li, Kai; Zhang, Bin; Wang, Jing-Jing +3 more
We performed new photometric and spectroscopic studies on six W UMa-type eclipsing binaries (V342 UMa, LX Leo, V1062 Her, V801 And, 1SWASP J165649.13+402738.4, and V1067 Her). From orbital period analysis, V342 UMa and LX Leo show continuous period decrease with a rate of -2.11(
Observed dispersive properties of the slow magnetoacoustic waves propagating in coronal fan loops above sunspots
Zhao, Junwei; Chen, Ruizhu; Wang, Tongjiang
Recurrent and propagating intensity perturbations are frequently observed in extreme ultraviolet (EUV) channels along coronal fan loops above sunspots, and these perturbations are suggested to be slow magnetoacoustic waves. Numerous studies have been conducted to investigate their propagation speeds, damping, and excitation sources; however, there…
Temporal variability and obscuration effects in the X-ray emission of classical nova V339 Delphini (Nova Delphini 2013)
Cai, Yongzhi; Pei, Songpeng; Li, Qiang +4 more
In this study, we present a detailed analysis of public archival soft X-ray data on the classical nova V339 Delphini (Nova Del 2013) during its outburst, obtained using the Chandra High-Resolution Camera Spectrometer and Low Energy Transmission Grating, as well as XMM-Newton in 2013. The observations, spanning from days 85.2 to 112.0 after the opt…
Cleaning WASP-33 b transits from the host star photometric variability: analysis of TESS data from two sectors
Baluev, Roman V.; Sokov, Eugene N.
Based on TESS observations of a
Two almost planetary mass survivors of common envelope evolution
Dhillon, V. S.; Littlefair, S. P.; Hollands, M. A. +19 more
White dwarfs are often found in close binaries with stellar or even substellar companions. It is generally thought that these compact binaries form via common envelope evolution, triggered by the progenitor of the white dwarf expanding after it evolved off the main sequence and engulfing its companion. To date, a handful of white dwarfs in compact…
The ultraviolet luminosity function of star-forming galaxies between redshifts of 0.4 and 0.6
McHardy, I.; Page, M. J.; Seymour, N. +7 more
We combine ultraviolet imaging of the