Search Publications
Spectroscopic study of CEMP-(s & r/s) stars. Revisiting classification criteria and formation scenarios, highlighting i-process nucleosynthesis
Goswami, Aruna; Goswami, Partha Pratim; Rathour, Rajeev Singh
Context. The origin of the enhanced abundances of both s- and r-process elements observed in a subclass of carbon-enhanced metal-poor (CEMP) stars, denoted CEMP-r/s stars, still remains poorly understood. The i-process nucleosynthesis has been suggested as one of the most promising mechanisms for the origin of these stars.
Aims: Our aim is to…
Day-night differences in Mars methane suggest nighttime containment at Gale crater
Atreya, Sushil K.; Vasavada, Ashwin R.; Moores, John E. +10 more
We report new measurements of atmospheric methane by the Curiosity rover's Tunable Laser Spectrometer that is part of the Sample Analysis at Mars suite (TLS-SAM), finding nondetections during two daytime measurements of average value 0.05 ± 0.22 ppbv (95% confidence interval CI). These are in marked contrast with nighttime background levels of 0.5…
Refined physical parameters for Chariklo's body and rings from stellar occultations observed between 2013 and 2020
Colas, F.; Bérard, D.; Snodgrass, C. +78 more
Context. The Centaur (10199) Chariklo has the first ring system discovered around a small object. It was first observed using stellar occultation in 2013. Stellar occultations allow sizes and shapes to be determined with kilometre accuracy, and provide the characteristics of the occulting object and its vicinity.
Aims: Using stellar occultati…
Jets from young stars
Ray, T. P.; Ferreira, J.
Jets are ubiquitous in the Universe and are seen from a large number of astrophysical objects including active galactic nuclei, gamma ray bursters, micro-quasars, proto-planetary nebulae, young stars and even brown dwarfs. In every case they seem to be accompanied by an accretion disk and, while the detailed physics may change, it has been suggest…
The Gaia DR2 halo white dwarf population: the luminosity function, mass distribution, and its star formation history
Rebassa-Mansergas, Alberto; Raddi, Roberto; Torres, Santiago +1 more
We analyse the volume-limited nearly complete 100 pc sample of 95 halo white dwarf candidates identified by the second data release of Gaia. Based on a detailed population synthesis model, we apply a method that relies on Gaia astrometry and photometry to accurately derive the individual white dwarf parameters. This method is tested with 25 white …
Improved Constraints on the Initial-to-final Mass Relation of White Dwarfs Using Wide Binaries
Chanamé, Julio; Barrientos, Manuel
We present observational constraints for the initial-to-final mass relation (IFMR) derived from 11 white dwarfs (WDs) in wide binaries (WBs) that contain a turnoff/subgiant primary. Because the components of WBs are coeval to a good approximation, the age of the WD progenitor can be determined from the study of its wide companion. However, previou…
SN 2017gci: a nearby Type I Superluminous Supernova with a bumpy tail
Sollerman, J.; Gromadzki, M.; Jerkstrand, A. +27 more
We present and discuss the optical spectrophotometric observations of the nearby (z = 0.087) Type I superluminous supernova (SLSN I) SN 2017gci, whose peak K-corrected absolute magnitude reaches Mg = -21.5 mag. Its photometric and spectroscopic evolution includes features of both slow- and of fast-evolving SLSN I, thus favoring a contin…
Exploiting timing capabilities of the CHEOPS mission with warm-Jupiter planets
Alonso, R.; Deleuil, M.; Erikson, A. +75 more
We present 17 transit light curves of seven known warm-Jupiters observed with the CHaracterising ExOPlanet Satellite (CHEOPS). The light curves have been collected as part of the CHEOPS Guaranteed Time Observation (GTO) program that searches for transit-timing variation (TTV) of warm-Jupiters induced by a possible external perturber to shed light …
Nonequilibrium Flux Rope Formation by Confined Flares Preceding a Solar Coronal Mass Ejection
Masuda, Satoshi; Liu, Chang; Liu, Rui +3 more
We present evidence that a magnetic flux rope was formed before a coronal mass ejection (CME) and its associated long-duration flare during a pair of preceding confined eruptions and associated impulsive flares in a compound event in NOAA Active Region 12371. Extreme-ultraviolet images and the extrapolated nonlinear force-free field show that the …
Exploring the Solar Wind from Its Source on the Corona into the Inner Heliosphere during the First Solar Orbiter-Parker Solar Probe Quadrature
Telloni, Daniele; Zank, Gary P.; Susino, Roberto +68 more
This Letter addresses the first Solar Orbiter (SO)-Parker Solar Probe (PSP) quadrature, occurring on 2021 January 18 to investigate the evolution of solar wind from the extended corona to the inner heliosphere. Assuming ballistic propagation, the same plasma volume observed remotely in the corona at altitudes between 3.5 and 6.3 solar radii above …