Search Publications
Intensity contrast of solar network and faculae close to the solar limb, observed from two vantage points
Schmidt, W.; Woch, J.; Solanki, S. K. +44 more
Context. The brightness of faculae and network depends on the angle at which they are observed and the magnetic flux density. Close to the limb, the assessment of this relationship has until now been hindered by the increasingly lower signal in magnetograms.
Aims: This preliminary study aims to highlight the potential of using simultaneous ob…
Photometric and spectroscopic properties of the eclipsing system V864 Monocerotis
Hong, Kyeongsoo; Lee, Jae Woo; Park, Jang-Ho
We present the orbital period variability and evolutionary status of the W UMa-type binary system V864 Mon from accurately measured fundamental parameters. New BV photometric observations of this system were performed in 2019 January and 2022 January, and the first high-resolution spectroscopic observations were carried out on three nights between…
LAMOST medium-resolution spectroscopic survey of binarity and exotic star (LAMOST-MRS-B): Observation strategy and target selection
Tian, Hao; Liu, Chao; Zhang, Bo +15 more
LAMOST-MRS-B is one of the sub-surveys of LAMOST medium-resolution (R ~ 7500) spectroscopic survey. It aims at studying the statistical properties (e.g., binary fraction, orbital period distribution, mass ratio distribution) of binary stars and exotic stars. We intend to observe about 30000 stars (10 mag ≤ G < 14.5 mag) with at least 10 visits …
Constraints on clumps in the representative wind of the WN8 Wolf-Rayet star HD 96548 = WR 40 with simultaneous broad-band light and linear-polarization variability
Ignace, R.; Moffat, A. F. J.; Robert, C. +1 more
We report precision ground-based broad-band optical intensity and linear-polarization light curves for the sky's brightest WN8 star, WR 40. WN8 stars are notorious for their high level of variability, stemming from stochastic clumps in their strong winds that are slower and less hot than the winds of most other Wolf-Rayet (WR) stars. We confirm pr…
The Dynamics of Earth's Cusp in Response to the Interplanetary Shock
Zong, Qiugang; Kistler, Lynn; Fu, Suiyan +9 more
The Earth's magnetospheric cusp, a region with an off-equatorial magnetic field minimum, is an important place which directly transports plasma and energy from the solar wind into the magnetosphere and ionosphere. Its magnetic topology and charged particles therein are known to respond to the solar wind and the interplanetary magnetic field. Howev…
Chicxulub-like Gale impact into an ocean/land interface on Mars: An explanation for the formation of Mount Sharp
Dohm, James M.; Williams, Jean-Pierre; Fink, Wolfgang +2 more
A geologic investigation of Gale Crater and surrounding terrain was conducted combining orbital data with reported in situ information collected through the Mars Science Laboratory (MSL Curiosity) rover cameras to better explain the anomalous features in and nearby Gale Crater with the primary focus being the formational history of Aeolis Mons, in…
Beyond small-scale transients: A closer look at the diffuse quiet solar corona
Peter, H.; Chitta, L. P.; Solanki, S. K. +9 more
Aims: Within the quiet Sun corona imaged at 1 MK, much of the field of view consists of diffuse emission that appears to lack the spatial structuring that is so evident in coronal loops or bright points. Our aim is to determine if these diffuse regions are categorically different in terms of their intensity fluctuations and spatial configurat…
Spectroscopy of TOI-1259B - an unpolluted white dwarf companion to an inflated warm Saturn
Triaud, Amaury H. M. J.; El-Badry, Kareem; Fitzmaurice, Evan +7 more
TOI-1259 consists of a transiting exoplanet orbiting a main-sequence star, with a bound outer white dwarf (WDs) companion. Less than a dozen systems with this architecture are known. We conduct follow-up spectroscopy on the WD TOI-1259B using the Large Binocular Telescope to better characterize it. We observe only strong hydrogen lines, making TOI…
An Updated Line List for Spectroscopic Investigation of G Stars- I: Redetermination of the Abundances in the Solar Photosphere
Sahin, Timur; Bilir, Selcuk; Marismak, Mahmut +1 more
We propose a line list that may be useful for the abundance analysis of G-type stars in the wavelength range 4080 -- 6780 Å. It is expected that the line list will be useful for surveys/libraries with overlapping spectral regions (e.g. ELODIE/SOPHIE libraries, UVES-580 setting of Gaia-ESO), and in particular for the analysis of F- and G-type stars…
Precise Age for the Binary Star System 12 Com in the Coma Berenices Cluster
Klement, Robert; Monnier, John D.; Schaefer, Gail H. +11 more
We present measurements of the interferometrically resolved binary star system 12 Com and the single giant star 31 Com in the cluster Coma Berenices. 12 Com is a double-lined spectroscopic binary system consisting of a G7 giant and an A3 dwarf at the cluster turnoff. Using an extensive radial velocity data set and interferometric measurements from…