Search Publications
High-velocity CP2 stars in the Galactic halo
Paunzen, E.; Prišegen, M.; Faltová, N. +2 more
Context. The second subclass of chemically peculiar stars, the CP2 stars, are early-type stars exhibiting anomalous abundances with variable line strengths possibly also accompanied by photometric variability that typically belong to the Galactic disk. However, a small fraction of these objects were recently found to be located far from the Galact…
Multiwavelength study of radio galaxy Pictor A: detection of western hotspot in far-UV and possible origin of high energy emissions
Stalin, C. S.; Sreekumar, P.; Bhattacharya, Debbijoy +2 more
A comprehensive study of the nucleus and western hotspot of Pictor A is carried out using AstroSat observations, 13 yr of Fermi, and archival Swift observations along with other published data. We report the first detection of the western hotspot of Pictor A in the far-UV band using observations from AstroSat-UVIT. The broad-band SED of the wester…
Searching for quasi-periodic eruptions using machine learning
Young, A. J.; Webbe, Robbie
Quasi-periodic eruption (QPE) is a rare phenomenon in which the X-ray emission from the nuclei of galaxies shows a series of large amplitude flares. Only a handful of QPEs have been observed but the possibility remains that there are as yet undetected sources in archival data. Given the volume of data available a manual search is not feasible, and…
Third Epoch HST Imaging of a Nonradiative Shock in the Cygnus Loop Supernova Remnant
Blair, William P.; Raymond, John C.; Sankrit, Ravi
We present new HST/WFC3 optical images of a region in the northeastern part of the Cygnus Loop supernova remnant, which includes a well-studied Balmer-line filament. These data represent the third epoch of HST Hα imaging and a second epoch of [O III] λ5007 imaging of that particular filament. The Hα images were used to measure the proper motions a…
TOI-1055 b: Neptunian planet characterised with HARPS, TESS, and CHEOPS
Alonso, R.; Deleuil, M.; Erikson, A. +89 more
Context. TOI-1055 is a Sun-like star known to host a transiting Neptune-sized planet on a 17.5-day orbit (TOI-1055 b). Radial velocity (RV) analyses carried out by two independent groups using nearly the same set of HARPS spectra have provided measurements of planetary masses that differ by ∼2σ.
Aims: Our aim in this work is to solve the inco…
The First Photometric and Spectroscopic Study of Contact Binary V2840 Cygni
Jagirdar, Rukmini; Devarapalli, Shanti Priya; Pothuneni, Ravi Raja
The first photometric, spectroscopic and period variation studies of neglected short-period eclipsing binary V2840 Cygni are presented. High mass ratio contact binaries (HMRCBs), especially those in the weak-contact configuration, are vital when probing the evolutionary models of contact binaries (CBs) using stellar parameters. The photometric sol…
Low NH3/H2O ratio in comet C/2020 F3 (NEOWISE) at 0.7 au from the Sun
McGuire, Brett A.; Drozdovskaya, Maria N.; Opitom, Cyrielle +7 more
Context. A lower-than-solar elemental nitrogen content has been demonstrated for several comets, including 1P/Halley and 67P/Churyumov-Gerasimenko (67P/C-G) with independent in situ measurements of volatile and refractory budgets. The recently discovered semi-refractory ammonium salts in 67P/C-G are thought to be the missing nitrogen reservoir in …
TOI-858 B b: A hot Jupiter on a polar orbit in a loose binary
Bouchy, F.; Stassun, K.; Winn, J. N. +31 more
We report the discovery of a hot Jupiter on a 3.28-day orbit around a 1.08 M⊙ G0 star that is the secondary component in a loose binary system. Based on follow-up radial velocity observations of TOI-858 B with CORALIE on the Swiss 1.2 m telescope and CHIRON on the 1.5 m telescope at the Cerro Tololo Inter-American Observatory (CTIO), we…
A deep dive into the Type II globular cluster NGC 1851
Milone, A. P.; Cordoni, G.; Marino, A. F. +13 more
About one-fifth of the Galactic globular clusters (GCs), dubbed Type II GCs, host distinct stellar populations with different heavy elements abundances. NGC 1851 is one of the most studied Type II GCs, surrounded by several controversies regarding the spatial distribution of its populations and the presence of star-to-star [Fe/H], C+N+O, and age d…
The Second International Asteroid Warning Network Timing Campaign: 2005 LW3
Licandro, Javier; Granvik, Mikael; Thuillot, William +90 more
The Earth close approach of near-Earth asteroid 2005 LW3 on 2022 November 23 represented a good opportunity for a second observing campaign to test the timing accuracy of astrometric observation. With 82 participating stations, the International Asteroid Warning Network collected 1046 observations of 2005 LW3 around the time of the close approach.…