4,060 research outputs found
The LCOGT Network
Motivated by the increasing need for observational resources for the study of
time varying astronomy, the Las Cumbres Observatory Global Telescope (LCOGT) is
a private foundation, whose goal is to build a global network of robotic
telescopes for scientific research and education. Once completed, the network
will become a unique tool, capable of continuous monitoring from both the
Northern and Southern Hemispheres. The network currently includes 2 x 2.0 m
telescopes, already making an impact in the field of exoplanet research. In the
next few years they will be joined by at least 12 x 1.0 m and 20 x 0.4 m
telescopes. The increasing amount of LCOGT observational resources in the
coming years will be of great service to the astronomical community in general,
and the exoplanet community in particular.Comment: 2 pages, 1 figure, to appear in the proceedings of IAU Symposium 276
"The Astrophysics of Planetary Systems: Formation, Structure, and Dynamical
Evolution
The first high-amplitude delta Scuti star in an eclipsing binary system
We report the discovery of the first high-amplitude delta Scuti star in an
eclipsing binary, which we have designated UNSW-V-500. The system is an
Algol-type semi-detached eclipsing binary of maximum brightness V = 12.52 mag.
A best-fitting solution to the binary light curve and two radial velocity
curves is derived using the Wilson-Devinney code. We identify a late A spectral
type primary component of mass 1.49+/-0.02 M_sun and a late K spectral type
secondary of mass 0.33+/-0.02 M_sun, with an inclination of 86.5+/-1.0 degrees,
and a period of 5.3504751+/-0.0000006 d. A Fourier analysis of the residuals
from this solution is performed using PERIOD04 to investigate the delta Scuti
pulsations. We detect a single pulsation frequency of f_1 = 13.621+/-0.015 c/d,
and it appears this is the first overtone radial mode frequency. This system
provides the first opportunity to measure the dynamical mass for a star of this
variable type; previously, masses have been derived from stellar evolution and
pulsation models.Comment: 7 pages, 6 figures, 2 tables, for submission to MNRAS, v2: paper size
change, small typographical changes to abstrac
Deciphering metasomatic events beneath Mindszentkálla (Bakony- Balaton Highland Volcanic Field, western Pannonian Basin) revealed by single-lithology and composite upper mantle xenoliths
Single-lithology and composite xenoliths from Mindszentkálla (Bakony-Balaton
Highland Volcanic Field) in the Carpathian-Pannonian region record
geochemical evolution of the subcontinental lithospheric mantle. The
dominant single-lithology xenoliths are orthopyroxene-rich (22 vol% on
average) harzburgites. Three composite xenoliths contain either two or
more domains including dunite, olivine-orthopyroxenite, orthopyroxenite,
apatite-bearing websterite and amphibole-phlogopite-bearing vein. The
presence of different lithologies is a result of at least two metasomatic
events that affected the lithospheric mantle. The first event resulted in
orthopyroxene enrichment thus formed harzburgitic mantle volumes (Group
I xenoliths). Major- and trace element distributions of the bulk harzburgites
differ from the geochemical trends expected in residues of mantle melting. In
contrast, petrographic and geochemical attributes suggest that the harzburgite
was formed by silica-rich melt - peridotitic wall rock interactions in a suprasubduction
zone. Within the Group I xenoliths, two subgroups were identified
based on the presence or lack of enrichment in U, Pb and Sr. Since these
elements are fluid mobile, their enrichment in certain Group I xenoliths indicate
reaction with a subduction-related fluid, subsequent to the harzburgite
formation. The effect of a second event overprints the features of the Group
I xenoliths and is evidenced in all domains of two composite xenoliths (Group II
xenoliths). The general geochemical character involves enrichment of basaltic major and minor elements (Fe, Mn, Ti, Ca) in the rock-forming minerals and
convex-upward rare earth element (REE) patterns in clinopyroxenes. We
suggest that the different domains represent reaction products with variably
evolved basaltic melts of a single magmatic event. The tectonic background to
the formation of Group I xenoliths is likely linked to the subduction of oceanic
crust during the Mesozoic–Paleogene. This happened far from the current
position of Mindszentkálla, to where the lithosphere, including the
metasomatized mantle volume, was transferred via plate extrusion. The
Group II xenoliths appear to bear the geochemical signature of a younger
(Neogene) basaltic magmatic event, likely the same that produced the host
basalt transporting the xenoliths to the surface.New National Excellence Program of the Ministry for Innovation and Technology from the source of the National Research, Development and Innovation FundLenduelet Research Grant UNKP-21-4National Research, Development & Innovation Office (NRDIO) - Hungary K128122Orszagos Tudomanyos Kutatasi Alapprogramok (OTKA) LP-2018/5
NKFIH_FK research 78425National Science Centre, Poland 132418Eoetvoes Lorand University (ELTE) Institutional Excellence Program - Hungarian Ministry of Human Capacities 2019/33/B/ST10/03016
TKP2020-IKA-0
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