Search Publications
GAUSSN: Bayesian time-delay estimation for strongly lensed supernovae
Arendse, Nikki; Grayling, Matthew; Dhawan, Suhail +3 more
We present GAUSSN, a Bayesian semiparametric Gaussian Process (GP) model for time-delay estimation with resolved systems of gravitationally lensed supernovae (glSNe). GAUSSN models the underlying light curve non-parametrically using a GP. Without assuming a template light curve for each SN type, GAUSSN fits for the time delays of all images using …
BEBOP V. Homogeneous stellar analysis of potential circumbinary planet hosts
Hellier, Coel; Triaud, Amaury H. M. J.; Sairam, Lalitha +29 more
Planets orbiting binary systems are relatively unexplored compared to those around single stars. Detections of circumbinary planets and planetary systems offer a first detailed view into our understanding of circumbinary planet formation and dynamical evolution. The BEBOP (binaries escorted by orbiting planets) radial velocity survey plays a speci…
A benchmark white dwarf-ultracool dwarf wide field binary
Smith, Leigh C.; Minniti, Dante; Caceres, Claudio +8 more
We present the discovery and multiwavelength characterization of VVV J1438-6158 AB, a new field wide-binary system consisting of a $4.6^{+5.5}_{-2.4}~{\rm Gyr}$ and $T_{\rm eff} = 9500\pm 125~\mathrm{ K}$ DA white dwarf (WD) and a $T_{\rm eff} = 2400\pm 50~\mathrm{ K}$ M8 ultracool dwarf (UCD). The projected separation of the system is $a = 1236.7…
TESS duotransit candidates from the Southern Ecliptic Hemisphere
Ramsay, Gavin; Wheatley, Peter J.; Bayliss, Daniel +20 more
Discovering transiting exoplanets with long orbital periods allows us to study warm and cool planetary systems with temperatures similar to the planets in our own Solar system. The Transiting Exoplanet Survey Satellite (TESS) mission has photometrically surveyed the entire Southern Ecliptic Hemisphere in Cycle 1 (2018 August-2019 July), Cycle 3 (2…
Probing the accretion geometry of the atoll source 4U 1702-429 in different spectral states with NICER, NuSTAR, and AstroSat
Homan, Jeroen; Banerjee, Srimanta
We perform a comprehensive spectral study of a carefully selected sample (total exposure ~50.5 ks) of NICER observations of the atoll neutron star low-mass X-ray binary 4U 1702-429. Our sample encompasses nearly all classical spectral states found within the NICER data set. We require two thermal emission components, originating from the accretion…
A survey for variable young stars with small telescopes - VIII. Properties of 1687 Gaia selected members in 21 nearby clusters
Scholz, Aleks; Eislöffel, Jochen; Dvorak, Shawn +60 more
The Hunting Outbursting Young Stars (HOYS) project performs long-term, optical, multifilter, high cadence monitoring of 25 nearby young clusters and star-forming regions. Utilizing Gaia DR3 data, we have identified about 17 000 potential young stellar members in 45 coherent astrometric groups in these fields. Twenty one of them are clear young gro…
Photometric determination of main-sequence binaries with Gaia
Wallace, A. L.
Since its launch in 2013, the Gaia space telescope has provided precise measurements of the positions and magnitudes of over 1 billion stars. This has enabled extensive searches for stellar and substellar companions through astrometric and radial velocity measurements. However, these surveys require a prior knowledge of any unresolved companion af…
Optically quiet, but FUV loud: results from comparing the far-ultraviolet predictions of flare models with TESS and HST
Loyd, R. O. Parke; Jackman, James A. G.; Richey-Yowell, Tyler +1 more
The far-ultraviolet (FUV) flare activity of low-mass stars has become a focus in our understanding of the exoplanet atmospheres and how they evolve. However, direct detection of FUV flares and measurements of their energies and rates are limited by the need for space-based observations. The difficulty of obtaining such observations may push some w…
Multiband polarimetric imaging of HD 34700 with SCExAO/CHARIS
Currie, Thayne; Lewis, Briley L.; Uyama, Taichi +5 more
We present Subaru/SCExAO + CHARIS broad-band (JHK) integral field spectroscopy of HD 34700 A in polarized light. CHARIS has the unique ability to obtain polarized integral field images at 22 wavelength channels in broad-band, as the incoming light is first split into different polarization states before passing though the lenslet array. We recover…
The first glimpse of ULXs through the near-infrared images captured by the JWST
Allak, Sinan
This work presents the first results of near-infrared (NIR) counterparts of ultraluminous X-ray sources (ULXs) in the case of NGC 1672 by using JWST observations. Through advanced astrometry, unique counterparts were identified for four of the eight ULXs (ULX-1, ULX-4, ULX5, and ULX-8) located in NGC 1672, while multiple counterparts were identifi…