A neutron star candidate in the long-period binary 56 UMa
arXiv:2301.06531 · doi:10.1051/0004-6361/202245796
Abstract
56 UMa is a wide binary system that contains a chemically peculiar red giant and a faint companion. Due to its surface chemical abundances, the red giant was classified as a barium (Ba) star. This implies that the companion has to be a white dwarf, since Ba stars form when mass is transferred to them from an s-process rich Asymptotic Giant Branch (AGB) star. However, in the case of 56 UMa, the companion might be too massive to be the progeny of an AGB star that efficiently produced s-process elements such as barium. In this Letter, we revisit the orbital parameters of the system and perform a full spectral analysis with the goal of investigating the Ba-star classification of the giant and unravelling the nature of its faint companion. We combined radial-velocity and astrometric data to refine the orbital parameters of the system, including the orbital inclination and the companion mass. Then, we re-determined the stellar parameters of the giant and its chemical abundances using high-resolution HERMES spectra. Finally, we investigated the morphology of the interstellar gas in the vicinity of the system. The faint component in 56 UMa has a mass of M, which, together with the mixed s+r abundance profile of the red giant, confirms that the giant is not a standard barium star. Additionally, the clear identification of a cavity surrounding 56 UMa could indicate that a supernova explosion occurred about 10 5 years ago in the system, suggesting that the faint companion might be a neutron star. However, finding an evolutionary scenario that explains all the observables is not trivial, so we discuss different possible configurations of the system and their respective merits.
arXiv commentAccepted for publication in A&AL
References in corpus (49)
- emcee: The MCMC Hammer
- The chemical composition of the Sun
- Gaia Data Release 2. Summary of the contents and survey properties
- PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
- Validation of the new Hipparcos reduction
- A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
- Evolutionary tracks and isochrones for low- and intermediate-mass stars: from 0.15 to 7 M_sun, and from Z=0.0004 to 0.03
- Grids of stellar models with rotation - I. Models from 0.8 to 120 Msun at solar metallicity (Z = 0.014)
- HI4PI: A full-sky HI survey based on EBHIS and GASS
- Gaia Early Data Release 3: The astrometric solution
- The s Process: Nuclear Physics, Stellar Models, Observations
- Updated stellar yields from Asymptotic Giant Branch models
- PSR J0952-0607: The Fastest and Heaviest Known Galactic Neutron Star
- HERMES: a high-resolution fibre-fed spectrograph for the Mercator telescope
- The Evolution of Compact Binary Star Systems
- Evolution, nucleosynthesis and yields of low mass AGB stars
- A new implementation of the infrared flux method using the 2MASS catalogue
- Stellar and substellar companions of nearby stars from Gaia DR2 - Binarity from proper motion anomaly
- From binaries to multiples II: hierarchical multiplicity of F and G dwarfs
- The Hipparcos-Gaia Catalog of Accelerations: Gaia EDR3 Edition
- Abundances of 30 elements in 23 metal-poor stars
- The Hipparcos-Gaia Catalog of Accelerations
- Star formation near the Sun is driven by expansion of the Local Bubble
- Stellar Parameters and Elemental Abundances of Late-G Giants
- s-Process Nucleosynthesis in AGB Stars: A Test for Stellar Evolution
- Super-AGB Stars and their role as Electron Capture Supernova progenitors
- On the rate of core collapse supernovae in the Milky Way
- Rubidium-Rich Asymptotic Giant Branch Stars
- Atomic and Molecular Data for Optical Stellar Spectroscopy
- The XMM-Newton serendipitous ultraviolet source survey catalogue
- orvara: An Efficient Code to Fit Orbits using Radial Velocity, Absolute, and/or Relative Astrometry
- Barium & related stars and their white-dwarf companions I. Giant stars
- NLTE analysis of Sr lines in spectra of late-type stars with new R-matrix atomic data
- Hydrodynamical Neutron-star Kicks in Electron-capture Supernovae and Implications for the CRAB Supernova
- Barium & related stars and their white-dwarf companions II. Main-sequence and subgiant stars
- Revisiting the Parallax of the Isolated Neutron Star RX J185635-3754 Using HST/ACS Imaging
- Primordial r-process Dispersion in Metal-Poor Globular Clusters
- Determining Ages of APOGEE Giants with Known Distances
- Low-mass low-metallicity AGB stars as an efficient i-process site explaining CEMP-rs stars
- Hertzsprung-Russell diagram and mass distribution of barium stars
- When binaries keep track of recent nucleosynthesis: The Zr - Nb pair in extrinsic stars as an s-process diagnostic
- A persistent ultraviolet outflow from an accreting neutron star binary transient
- On the origins of enigmatic stellar populations in Local Group galactic nuclei
- Comment on "A non-interacting low-mass black hole -- giant star binary system"
- The Outcome of Supernovae in Massive Binaries; Removed Mass, and its Separation Dependence
- Barium and related stars, and their white-dwarf companions. III. The masses of the white dwarfs
- Probable Dormant Neutron Star in a Short-Period Binary System
- Sr and Ba abundance determinations: comparing machine-learning with star-by-star analyses -- High-resolution re-analysis of suspected LAMOST barium stars
- The Origin and Distance of the High-Velocity Cloud MI
Cited by in corpus (4)
- Barium and related stars, and their white-dwarf companions. III. The masses of the white dwarfs
- Vintage NPOI: New and Updated Angular Diameters for 145 Stars
- Supernovae Origin for the Low-Latitude-Intermediate-Velocity Arch and the North-Celestial-Pole Loop
- Indo-Belgian co-operation in Astrophysics: From inception to future prospects