Search Publications
Missions
Journals
Publication Years
Carbon dust in the evolved born-again planetary nebulae A 30 and A 78
Estrada-Dorado, S.; Guerrero, M. A.; Toalá, J. A. +6 more
We present an infrared (IR) characterization of the born-again planetary nebulae (PNe) A 30 and A 78 using IR images and spectra. We demonstrate that the carbon-rich dust in A 30 and A 78 is spatially coincident with the H-poor ejecta and coexists with hot X-ray-emitting gas up to distances of 50 arcsec from the central stars of PNe (CSPNe). Dust …
Evidence of Rocky Planet Engulfment in the Wide Binary System HIP 71726/HIP 71737
Meléndez, Jorge; Yana Galarza, Jhon; Lorenzo-Oliveira, Diego +1 more
Binary stars are supposed to be chemically homogeneous, as they are born from the same molecular cloud. However, high-precision chemical abundances show that some binary systems display chemical differences between the components, which could be due to planet engulfment. In this work, we determine precise fundamental parameters and chemical abunda…
Fermi-GBM Observations of GRB 210812A: Signatures of a Million Solar Mass Gravitational Lens
Veres, P.; Fraija, N.; Bhat, N. +1 more
Observing gravitationally lensed objects in the time domain is difficult, and well-observed time-varying sources are rare. Lensed gamma-ray bursts (GRBs) offer improved timing precision for this class of objects, complementing observations of quasars and supernovae. The rate of lensed GRBs is highly uncertain, approximately one in 1000. The Gamma-…
Ultralow Frequency Waves in Driving Jovian Aurorae Revealed by Observations From HST and Juno
Grodent, Denis; Bonfond, Bertrand; Wei, Yong +6 more
Large scale electrical currents and Alfvénic waves are the two main drivers responsible for producing planetary aurorae. The relative contribution of each process is a central question in terrestrial auroral science, and poorly understood for other planets due to the relatively rare opportunity of in situ spacecraft measurements. Here, we present …
The High-energy Spectrum of the Nearby Planet-hosting Inactive Mid-M Dwarf LHS 3844
Youngblood, Allison; Charbonneau, David; Kempton, Eliza M. -R. +5 more
To fully characterize the atmospheres, or lack thereof, of terrestrial exoplanets, we must include the high-energy environments provided by their host stars. The nearby mid-M dwarf LHS 3844 hosts a terrestrial world that lacks a substantial atmosphere. We present a time-series UV spectrum of LHS 3844 from 1131 to 3215 Å captured by HST/COS. We det…
Linking nearby stellar streams to more distant halo overdensities
Helmi, A.; Balbinot, E.
Context. It has recently been shown that the halo near the Sun contains several kinematic substructures associated with past accretion events. For the more distant halo, there is evidence of large-scale density variations - in the form of stellar clouds or overdensities.
Aims: We study the link between the local halo kinematic groups and thre…
Testing the Limits of Precise Subgiant Characterization with APOGEE and Gaia: Opening a Window to Unprecedented Astrophysical Studies
Stassun, Keivan G.; van Saders, Jennifer L.; Beaton, Rachael L. +6 more
Given their location on the Hertzsprung-Russell (H-R) diagram, thoroughly characterized subgiant stars can place stringent constraints on a wide range of astrophysical problems. Accordingly, they are prime asteroseismic targets for the Transiting Exoplanet Survey Satellite (TESS) mission. In this work, we infer stellar properties for a sample of 3…
The effect of varying porosity and inhomogeneities of the surface dust layer on the modelling of comet gas production
Skorov, Yuri; Reshetnyk, Volodymyr; Blum, Jürgen +3 more
We study how uncertainties in knowledge of the microstructure of the porous dust surface layer affect our estimates of effective gas production of comet 67P/Churyumov-Gerasimenko. We analyse the transport properties (distribution of free paths, mean pore size, permeability) for random densely packed porous layers. Bimodal layers, as well as variou…
Asteroseismology of overmassive, undermassive, and potential past members of the open cluster NGC 6791
Miglio, A.; Brogaard, K.; Arentoft, T. +1 more
We perform an asteroseismic investigation of giant stars in the field of NGC 6791 with previous indications of atypical evolution. The analysis uses observations from Kepler and Gaia in combination with ground-based photometry, a literature radial-velocity study, and measurements of eclipsing binaries in the cluster. We derive mass, radius, effect…
Distances to molecular clouds in the second Galactic quadrant
Wang, Hongchi; Xu, Ye; Su, Yang +5 more
We present distances to 76 medium-sized molecular clouds and an extra large-scale molecular cloud in the second Galactic quadrant (104. °75 < l < 150. °25 and |b| < 5. °25), 73 of which are accurately measured for the first time. Molecular cloud samples are drawn from l-b-V space (- 95 < VLSR < 25 km s-1) with …