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The population of M dwarfs observed at low radio frequencies
(2021-12-30)
Coherent low-frequency (≲200 MHz) radio emission from stars encodes the conditions of the outer corona, mass-ejection events and space weather 1–5. Previous low-frequency searches for radio-emitting stellar systems have ...
The Radioactive Nuclei 26Al and 60Fe in the Cosmos and in the Solar System
(2021-12-09)
The cosmic evolution of the chemical elements from the Big Bang to the present time is driven by nuclear fusion reactions inside stars and stellar explosions. A cycle of matter recurrently re-processes metal-enriched stellar ...
The first retrieval of a substellar subdwarf: A cloud-free SDSS J125637.13-022452.4
(2021-12-08)
We present the first retrieval analysis of a substellar subdwarf, SDSS J125637.13-022452.4 (SDSS J1256-0224), using the Brewster retrieval code base. We find SDSS J1256-0224 is best fit by a cloud-free model with an ion ...
High resolution spectroscopic follow-up of the most metal-poor candidates from SkyMapper DR1.1
(2021-11-01)
We present chemical abundances for 21 elements (from Li to Eu) in 150 metal-poor Galactic stars spanning -4.1 < [Fe/H] < -2.1. The targets were selected from the SkyMapper survey and include 90 objects with [Fe/H] ≤ -3 of ...
Variable star classification across the Galactic bulge and disc with the VISTA Variables in the Vía Láctea survey
(2021-10-30)
We present VIVACE, the VIrac VAriable Classification Ensemble, a catalogue of variable stars extracted from an automated classification pipeline for the Vista Variables in the V\'ia L\'actea (VVV) infrared survey of the ...
The JCMT Transient Survey: Four-year Summary of Monitoring the Submillimeter Variability of Protostars
(2021-10-21)
We present the four-year survey results of monthly submillimeter monitoring of eight nearby ($<500 $pc) star-forming regions by the JCMT Transient Survey. We apply the Lomb-Scargle Periodogram technique to search for and ...
A Catalog of Potential Post–Common Envelope Binaries
(2021-10-20)
We present a catalogue containing 839 candidate post common envelope systems. Common envelope evolution is very important in stellar astrophysics, particularly in the context of very compact and short-period binaries, ...
Barium lines in high-quality spectra of two metal-poor giants in the Galactic halo
(2021-10-01)
Context. Theoretical results showed the possibility that neutron capture elements were produced in the early Universe by two different sources: a frequent s-process source hosted by rotating massive stars, and a rare ...
Optimized modeling of Gaia-Hipparcos astrometry for the detection of the smallest cold Jupiter and confirmation of seven low mass companions
(2021-08-03)
To fully constrain the orbits of low mass circumstellar companions, we conduct combined analyses of the radial velocity data as well as the Gaia and Hipparcos astrometric data for eight nearby systems. Our study shows that ...
Variable stars in the VVV globular clusters. II. NGC6441, NGC6569, NGC6626 (M28), NGC6656 (M22), 2MASS-GC02, and Terzan10
(2021-07-12)
Context. The Galactic globular clusters (GGCs) located in the inner regions of the Milky Way suffer from high extinction that makes their observation challenging. High densities of field stars in their surroundings complicate ...