Search Publications
Mid-infrared reflectance spectroscopy of aubrite components
Helbert, Joern; Hiesinger, Harald; Weber, Iris +5 more
Aubrites Peña Blanca Spring and Norton County were studied in the mid-infrared reflectance as part of a database for the MERTIS (Mercury Radiometer and Thermal Infrared Spectrometer) instrument on the ESA/JAXA BepiColombo mission to Mercury. Spectra of bulk powder size fractions from Peña Blanca Spring show enstatite Reststrahlen bands (RB) at 9 µ…
Binary star sequence in the outskirts of the disrupting Galactic open cluster UBC 274
Piatti, Andrés E.
We report the identification of a numerous binary star population in the recently discovered ∼3 Gyr old open cluster UBC 274. It becomes visible when the cluster color-magnitude diagram is corrected by differential reddening and spans mass ratio (q) values from 0.5 up to 1.0. Its stellar density radial profile and cumulative distribution as a func…
LAMOST J040643.69+542347.8: The Fastest Rotator in the Galaxy
Li, Guang-Wei
Rotation and binary interaction play important roles in understanding the nature of massive stars (≳8M⊙). Some interesting transients, such as the long-duration gamma-ray bursts, are thought to be originated from fast-rotating massive stars. Because the strong stellar wind can effectively spin down a metal-rich massive star with fast ro…
Automatic Coronagraph Image Classification with Machine Learning Methods
Zhang, Yan; Feng, Li; Li, Hui +5 more
The detection of Coronal Mass Ejections (CMEs) is an important prerequisite for establishing a CME event database and realizing the prediction of CME interplanetary propagation. The Lyman-alpha Solar Telescope (LST) aboard the ASO-S (Advanced Space-based Solar Observatory) satellite will be equipped with a white-light coronagraph. The images with …
Interstellar Extinction in the Direction of the Young Open Cluster NGC 6530
Topasna, G. A.; Kaltcheva, N. T.; Jones, R. H.
We present UBVRI polarization observations of 12 B-type stars in the direction of the young open cluster NGC 6530, nine of them confirmed as probable members. The maximum degree of polarization for our target stars ranges from 0.16% to 2.84%, with an average value of 1.1%. We note variations of the polarization vector orientations across the clust…
Leveraging HST with MUSE: II. Na-abundance variations in intermediate age star clusters
Martocchia, S.; Salaris, M.; Larsen, S. +13 more
Ancient (>10 Gyr) globular clusters (GCs) show chemical abundance variations in the form of patterns among certain elements, e.g. N correlates with Na and anticorrelates with O. Recently, N abundance spreads have also been observed in massive star clusters that are significantly younger than old GCs, down to an age of ~2 Gyr. However, so far N …
Statistical analysis of solar wind parameter variation with heliospheric distance: Ulysses observations in the ecliptic plane
Bolzan, M. J. A.; Echer, E.; Franco, A. M. S.
The interplanetary magnetic field magnitude Bo, proton density Np and solar wind speed Vsw data from Ulysses spacecraft during its interplanetary cruise interval from Earth to Jupiter, from 18 November 1990 to 31 January 1992, are analyzed in this study. Statistical and wavelet techniques are employed to characteri…
Chandra observations of the planetary nebula IC 4593
Bianchi, L.; Chu, Y. -H.; Guerrero, M. A. +2 more
The Advanced CCD Imaging Spectrometer (ACIS-S) camera on board the Chandra X-ray Observatory has been used to discover a hot bubble in the planetary nebula (PN) IC 4593, the most distant PN detected by Chandra so far. The data are used to study the distribution of the X-ray-emitting gas in IC 4593 and to estimate its physical properties. The hot b…
Morphological and morphometric analysis of a topographic depression near Huygens basin, Mars: Identification of a putative endorheic playa
Singh, Deepali; Singh, Priyadarshini; Roy, Nidhi +1 more
Inter-crater depressions on Mars, which may be host to candidate lakes, have not been explored in much detail. Even if a small percentage of these depressions were actually filled with water, it would mean that Mars was hydrologically more active than previously thought. The present study examined valley networks within the equatorial region of Ma…
Saturn's C ring and Cassini division: Particle sizes from Cassini UVIS, VIMS, and RSS occultations
Nicholson, Philip D.; French, Richard G.; Hedman, Matthew M. +4 more
Saturn's C ring and Cassini Division share many morphological traits: both contain numerous opaque, sharp-edged ringlets and gaps, broader low optical depth "background" regions, larger-optical depth regions that rise abruptly from the background (known as the C ring's plateaus and the Cassini Division's triple band feature), and linear ramps in o…