Search Publications
Informing the Cataclysmic Variable Sequence from Gaia Data: The Orbital-period-Color-Absolute-magnitude Relationship
Rix, Hans-Walter; Szkody, Paula; Bloom, Joshua S. +2 more
The orbital-period (P orb) gap in the population of cataclysmic variables (CVs) informs the theoretical narrative of CV evolution, yet a complete understanding of the driving angular momentum loss mechanisms above and below this gap remains elusive. Here we identify, for standard CVs, a new, apparently monotonic relationship between qui…
Analysis of the Evolution of a Multi-Ribbon Flare and Failed Filament Eruption
Schmieder, Brigitte; Joshi, Reetika; Chandra, Ramesh +5 more
How filaments form and erupt are topics about which solar researchers have wondered for more than a century and they are still open to debate. We present observations of a filament formation, its failed eruption, and the associated flare (SOL2019-05-09T05:51) that occurred in active region (AR) 12740 using data from the Solar Dynamics Observatory …
The Origin of the Vanishing Soft X-Ray Excess in the Changing-look Active Galactic Nucleus Mrk 590
Dewangan, Gulab C.; Laha, Sibasish; Bhalerao, Varun +3 more
We have studied the nature and origin of the soft X-ray excess detected in the interesting changing-look active galactic nucleus (CLAGN) Mrk 590 using two decades of multiwavelength observations from XMM-Newton, Suzaku, Swift, and NuSTAR. In light of vanishing soft excess in this CLAGN, we test two models, "the warm Comptonization" and "the ionize…
Absolute colors and phase coefficients of asteroids
Alvarez-Candal, A.; Colazo, M.; Jimenez Corral, S.
Context. We use the phase curves of small bodies to measure absolute magnitudes and, together with complementary theoretical and laboratory results, to understand the micro- and macroscopic properties of their surfaces. Although we can observe asteroids up to phase angles of about 30 deg, the range of phase angles covered by outer Solar System obj…
Analysis of high-resolution FEROS spectroscopy for a sample of variable B-type stars assembled from TESS photometry
Xiang, Maosheng; Rix, Hans-Walter; Bowman, Dominic M. +8 more
Context. Spectroscopic data are necessary to break degeneracies in the asteroseismic modelling of the interior structure in high- and intermediate-mass stars. With the TESS mission, the number of bright intermediate-mass B-type stars with long photometric light curves that are suitable for detailed asteroseismic studies has increased substantially…
Sgr B2 hard X-ray emission with INTEGRAL after 2009: still detectable?
Krivonos, Roman; Clavel, Maïca; Kuznetsova, Ekaterina +1 more
The molecular cloud Sgr B2 is a natural Compton mirror in the Central Molecular Zone. It is believed that the observed fading of the Sgr B2 X-ray emission in continuum and the Fe Kα 6.4 keV line indicates past X-ray flare activity of the supermassive black hole Sgr A⋆. Sgr B2 was investigated by the INTEGRAL observatory in the hard X-ra…
Characterizing eclipsing white dwarf M dwarf binaries from multiband eclipse photometry
Dhillon, V. S.; Parsons, Steven G.; Breedt, E. +10 more
With the prevalence of wide-field, time-domain photometric sky surveys, the number of eclipsing white dwarf (WD) systems being discovered is increasing dramatically. An efficient method to follow these up will be key to determining any population trends and finding any particularly interesting examples. We demonstrate that multiband eclipse photom…
A Hot Mars-sized Exoplanet Transiting an M Dwarf
Cochran, William D.; Endl, Michael; Mahadevan, Suvrath +21 more
We validate the planetary nature of an ultra-short-period planet orbiting the M dwarf KOI-4777. We use a combination of space-based photometry from Kepler, high-precision, near-infrared Doppler spectroscopy from the Habitable-zone Planet Finder, and adaptive optics imaging to characterize this system. KOI-4777.01 is a Mars-sized exoplanet (R …
UVIT view of Centaurus A: a detailed study on positive AGN feedback
Mathew, Blesson; Paul, K. T.; Stalin, C. S. +4 more
Supermassive black holes at the centre of active galactic nuclei (AGNs) produce relativistic jets that can affect the star formation characteristics of the AGN hosts. Observations in the ultraviolet (UV) band can provide an excellent view of the effect of AGN jets on star formation. Here, we present a census of star formation properties in the Nor…
Statistical Analysis of Circular-ribbon Flares
Xu, Zhe; Li, Shuting; Zhang, Qingmin +4 more
Circular-ribbon flares (CFs) are a special type of solar flares owing to their particular magnetic topology. In this paper, we conducted a comprehensive statistical analysis of 134 CFs from 2011 September to 2017 June, including 4 B-class, 82 C-class, 40 M-class, and 8 X-class flares. The flares were observed by the Atmospheric Imaging Assembly on…