Search Publications
Improved Main-sequence Turnoff Ages of Young Open Clusters: Multicolor UBV Techniques and the Challenges of Rotation
Cummings, Jeffrey D.; Kalirai, Jason S.
Main-sequence turnoff ages in young open clusters are complicated by turnoffs that are sparse, have high binarity fractions, can be affected by differential reddening, and typically include a number of peculiar stars. Furthermore, stellar rotation can have a significant effect on a star’s photometry and evolutionary timescale. In this paper we ana…
Local measurements of the mean interstellar polarization at high Galactic latitudes
Blinov, D.; Liodakis, I.; Panopoulou, G. V. +4 more
Very little information exists concerning the properties of the interstellar medium (ISM)-induced starlight polarization at high Galactic latitudes. Future optopolarimetric surveys promise to fill this gap. We conduct a small-scale pathfinding survey designed to identify the average polarization properties of the diffuse ISM locally, at regions wi…
Electron Acceleration and Jet-facilitated Escape in an M-class Solar Flare on 2002 August 19
Fleishman, Gregory D.; Glesener, Lindsay
Sudden jets of collimated plasma arise from many locations on the Sun, including active regions. The magnetic field along which a jet emerges is often open to interplanetary space, offering a clear “escape route” for any flare-accelerated electrons, making jets lucrative targets for studying particle acceleration and the solar sources of transient…
Solar meridional circulation from twenty-one years of SOHO/MDI and SDO/HMI observations. Helioseismic travel times and forward modeling in the ray approximation
Gizon, Laurent; Liang, Zhi-Chao; Birch, Aaron C. +2 more
Context. The solar meridional flow is an essential ingredient in flux-transport dynamo models. However, no consensus on its subsurface structure has been reached.
Aims: We merge the data sets from SOHO/MDI and SDO/HMI with the aim of achieving a greater precision on helioseismic measurements of the subsurface meridional flow.
Methods: Th…
The Complete Local-volume Groups Sample - II. A study of the central radio galaxies in the high-richness sub-sample
Babul, Arif; Raychaudhury, Somak; Giacintucci, Simona +3 more
We present a study of the radio properties of the dominant early-type galaxies in 26 galaxy groups, the high-richness sub-sample of the Complete Local-volume Groups Sample (CLoGS). Combining new 610 and 235 MHz observations of 21 groups from the Giant Metrewave Radio Telescope (GMRT) with archival GMRT and Very Large Array (VLA) survey data, we fi…
Geological Features and Evolution of Yardangs in the Qaidam Basin, Tibetan Plateau (NW China): A Terrestrial Analogue for Mars
Huang, Jun; Xiao, Long; Xu, Yi +6 more
Wind-eroded ridges known as yardangs are common in most arid desert regions on Earth, as well as on other planets, notably in the Medusae Fossae Formation (MFF) and Gale Crater on Mars. However, the formation and evolution of these various yardangs are not well understood, which, therefore, requires further studies by more terrestrial analogues. H…
Automated Identification of Coronal Holes from Synoptic EUV Maps
Asikainen, Timo; Mursula, Kalevi; Virtanen, Ilpo +1 more
Coronal holes (CHs) are regions of open magnetic field lines in the solar corona and the source of the fast solar wind. Understanding the evolution of coronal holes is critical for solar magnetism as well as for accurate space weather forecasts. We study the extreme ultraviolet (EUV) synoptic maps at three wavelengths (195 Å/193 Å, 171 Å and 304 Å…
SPOTS: The Search for Planets Orbiting Two Stars. III. Complete sample and statistical analysis
Kuzuhara, M.; Marzari, F.; Henning, Th. +8 more
Binary stars constitute a large percentage of the stellar population, yet relatively little is known about the planetary systems orbiting them. Most constraints on circumbinary planets (CBPs) so far come from transit observations with the Kepler telescope, which is sensitive to close-in exoplanets but does not constrain planets on wider orbits. Ho…
Testing models of stellar structure and evolution - I. Comparison with detached eclipsing binaries
del Burgo, C.; Allende Prieto, C.
We present the results of an analysis aimed at testing the accuracy and precision of the PARSEC v1.2S library of stellar evolution models, combined with a Bayesian approach, to infer stellar parameters. We mainly employ the online DEBCat catalogue by Southworth, a compilation of detached eclipsing binary systems with published measurements of mass…
Star formation complexes in the `galaxy-sized' supergiant shell of the galaxy HolmbergI
Egorov, Oleg V.; Lozinskaya, Tatiana A.; Moiseev, Alexei V. +1 more
We present the results of observations of the galaxy Holmberg I carried out at the Russian 6-m telescope in the narrow-band imaging, long-slit spectroscopy, and scanning Fabry-Perot interferometer modes. A detailed analysis of gas kinematics, ionization conditions, and metallicity of star-forming regions in the galaxy is presented. The aim of the …