Search Publications
Combining Astrometry and Elemental Abundances: The Case of the Candidate Pre-Gaia Halo Moving Groups G03-37, G18-39, and G21-22
Agüeros, Marcel A.; Schuler, Simon C.; Andrews, Jeff J. +3 more
While most moving groups are young and nearby, a small number have been identified in the Galactic halo. Understanding the origin and evolution of these groups is an important piece of reconstructing the formation history of the halo. Here we report on our analysis of three putative halo moving groups: G03-37, G18-39, and G21-22. Based on Gaia EDR…
LIStEN: L' band Imaging Survey for Exoplanets in the North
Henning, Thomas; Ertel, Steve; Musso Barcucci, Arianna +9 more
Context. Planetary systems and debris discs are natural by-products of the star formation process, and they affect each other. The direct imaging technique allows simultaneous imaging of both a companion and the circumstellar disc it resides in, and is thus a valuable tool to study companion-disc interactions. However, the number of systems in whi…
Stellar and Accretion Disk Parameters of the Close Binary HD 50526
Mennickent, R. E.; Zharikov, S.; Djurašević, G. +5 more
We present a photometric and spectroscopic study of HD 50526, an ellipsoidal binary member of the group Double Periodic Variable stars. Performing data mining in photometric surveys and conducting new spectroscopic observations with several spectrographs during 2008-2015, we obtained orbital and stellar parameters of the system. The radial velocit…
Heavy-element Rydberg transition line emission from the post-giant-evolution star HD 101584
Lindqvist, M.; Olofsson, H.; Black, J. H. +7 more
Context. We report the detection of two lines at millimetre wavelengths towards the immediate surroundings of the post-giant and most likely post-common-envelope star HD 101584 using high-angular-resolution ALMA observations. The circumstellar environment of this object is rich in different molecular species, but we find no viable identifications …
The First Radio Spectrum of a Rapidly Rotating A-type Star
De la Luz, V.; Moór, A.; Fehér, O. +9 more
The radio spectra of main-sequence stars remain largely unconstrained due to the lack of observational data to inform stellar atmosphere models. As such, the dominant emission mechanisms at long wavelengths, how they vary with spectral type, and how much they contribute to the expected brightness at a given radio wavelength are still relatively un…
Investigation of the shortest period Am type eclipsing binary TYC 6408-989-1
Tian, Xiao-Man
The first BV bands photometric observations and the low-resolution spectrum of the shortest period Am type eclipsing binary TYC 6408-989-1 have been obtained. The stellar atmospheric parameters of the primary star were obtained through the spectral fitting as follows: Teff = 6990 ± 117 K, log g = 4.25 ± 0.26 cm s-2, [Fe/H] = …
Evidence of the nonstationarity of the terrestrial bow shock from multi-spacecraft observations: methodology, results, and quantitative comparison with particle-in-cell (PIC) simulations
Mazelle, Christian; Lembège, Bertrand
The nonstationarity of the terrestrial bow shock is analyzed in detail from in situ magnetic field measurements issued from the fluxgate magnetometer (FGM) experiment of the Cluster mission. Attention is focused on statistical analysis of quasi-perpendicular supercritical shock crossings. The present analysis stresses for the first time the import…
Rotational excitation of highly excited H2O by H2
Żóltowski, Michal; Lique, François; Karska, Agata +1 more
Water is a key molecule for interstellar chemistry. Observations with Herschel telescope show significant population of very high rotational transitions (j ≳ 8) in young stellar objects, indicating significant amounts of water in hot (T ≳ 1500 K) and dense (n ≳ 106 cm-3) gas. Non-local thermodynamic equilibrium (LTE) modellin…
High-resolution CARMA Observation of Molecular Gas in the North America and Pelican Nebulae
Mairs, Steve; Nakamura, Fumitaka; Klessen, Ralf S. +15 more
In this paper, we present the first results from a CARMA high-resolution 12CO(1-0), 13CO(1-0), and C18O(1-0) molecular line survey of the North America and Pelican (NAP) Nebulae. CARMA observations have been combined with single-dish data from the Purple Mountain 13.7 m telescope, to add short spacings and to produ…
K2, Spitzer, and TESS Transits of Four Sub-Neptune Exoplanets
Deming, Drake; Crossfield, Ian; Harada, Caleb K. +5 more
We present new Spitzer transit observations of four K2 transiting sub-Neptunes: K2-36 c, K2-79b, K2-167b, and K2-212b. We derive updated orbital ephemerides and radii for these planets based on a joint analysis of the Spitzer, TESS, and K2 photometry. We use the EVEREST pipeline to provide improved K2 photometry, by detrending instrumental noise a…