Search Publications
A multiband look at ultraluminous X-ray sources in NGC 7424
Soria, Roberto; Russell, Thomas D.; Motch, Christian +2 more
We studied the multiband properties of two ultraluminous X-ray sources (2CXO J225728.9-410211 = X-1 and 2CXO J225724.7-410343 = X-2) and their surroundings, in the spiral galaxy NGC 7424. Both sources have approached X-ray luminosities LX ~ 1040 erg s-1 at some epochs. Thanks to a more accurate astrometric solution…
Constraining planetary albedo of JWST targets in the TESS bandpass, using TESS, HST, and Spitzer eclipse depth observations
Goyal, Jayesh; Arora, Rahul
Albedo is one of the important characteristics of hot Jupiter exoplanets. However, albedo constraints have been obtained for very few exoplanets. In this work, we present the Transiting Exoplanet Survey Satellite (TESS) phase curve observations of WASP-18b, WASP-19b, WASP-121b, WASP-43b, WASP-17b, and WASP-77b, all targets for atmospheric characte…
DanceCam: atmospheric turbulence mitigation in wide-field astronomical images with short-exposure video streams
Cuillandre, Jean-Charles; Bialek, Spencer; Bertin, Emmanuel +4 more
We introduce a novel technique to mitigate the adverse effects of atmospheric turbulence on astronomical imaging. Utilizing a video-to-image neural network trained on simulated data, our method processes a sliding sequence of short-exposure (~0.2 s) stellar field images to reconstruct an image devoid of both turbulence and noise. We demonstrate th…
Spectro-photometric follow-up of the outbursting AM CVn system ASASSN-21br
Mukai, K.; Maccarone, T. J.; Kochanek, C. S. +8 more
We report on spectroscopic and photometric observations of the AM Canum Venaticorum (AM CVn) system ASASSN-21br, which was discovered in outburst by the All-Sky Automated Survey for Supernovae in 2021 February. The outburst lasted for around three weeks, and exhibited a pronounced brightness dip for $\approx$4 d, during which the spectra showed a …
Photometric recalibration of VPHAS+ u-band photometry with the stellar colour regression method and Gaia DR3
Yuan, Hai-Bo; Chen, Bing-Qiu; Huang, Bo-Wen
The u-band magnitude is vital for determining stellar parameters and investigating specific astronomical objects. However, flux calibration in the u band for stars in the Galactic disc presents significant challenges. In this study, we introduce a comprehensive recalibration of u-band photometric magnitudes of the VPHAS+ Data Release 4, employing …
Radial velocity analysis of stars with debris discs
Jones, Hugh R. A.; Bisht, Deepak
This study aims to identify potential exoplanet signals from nearby stars with resolved debris discs. However, the high activity of many stars with debris discs limits the detection of periodic signals. Our study is constrained to a sample of 29 stars that have appropriate radial velocity data and debris disc measurements sufficient to resolve the…
Correction to: Stellar clustering and the kinematics of stars around Collinder 121 using Gaia DR3
Ward-Thompson, Derek; Fleming, Graham D.; Kirk, Jason M.
Localized ejection of dust and chunks on comet 67P/Churyumov-Gerasimenko: testing how comets work
Blum, J.; Gundlach, B.; Attree, N. +2 more
We extend an existing thermophysical activity model of comet 67P/Churyumov-Gerasimenko to include pressure build-up inside the pebbles making up the nucleus. We test various quantities of H
Investigating scaling relations in X-ray reverberating AGN using symbolic regression
Chainakun, P.; Young, A. J.; Thongkonsing, P. +1 more
Symbolic regression (SR) is a regression analysis based on genetic algorithms to search for mathematical expressions that best fit a given data set, by allowing the expressions themselves to mutate. We use the SR to analyse the parameter relations of the X-ray reverberating active galactic nuclei where the soft Fe-L lags were observed by the X-ray…
4U 1210-64: a new member of the rare intermediate-mass X-ray binary subclass
Montesinos, B.; McBride, V. A.; Pottschmidt, K. +5 more
4U 1210-64 is a peculiar X-ray binary that was first discovered in 1978 by the Uhuru satellite. The analysis of the X-ray data revealed a 6.7-d orbital period and an additional long-term modulation that is manifested as low- and high-flux states. Based on the previous classification of the donor star from the analysis of its optical spectra, the s…