288 research outputs found
Red giants from the Pennsylvania - Torun Planet Search
The main goal of the Pennsylvania - Torun Planet Search (PTPS) is detection
and characterization of planets around evolved stars using the high-accuracy
radial velocity (RV) technique. The project is performed with the 9.2 m
Hobby-Eberly Telescope. To determine stellar parameters and evolutionary status
for targets observed within the survey complete spectral analysis of all
objects is required. In this paper we present the atmospheric parameters
(effective temperatures, surface gravities, microturbulent velocities and
metallicities) of a subsample of Red Giant Clump stars using strictly
spectroscopic methods based on analysis of equivalent widths of Fe I and Fe II
lines. It is shown that our spectroscopic approach brings reliable and
consistent results.Comment: 3 pages, 2 figures, proceeding of the conference "New Technologies
for Probing the Diversity of Brown Dwarfs and Exoplanets" (Shangai, China,
July 19-24, 2009), to appear in EPJ Web of Conference
A Planet in a 0.6-AU Orbit Around the K0 Giant HD 102272
We report the discovery of one or more planet-mass companions to the K0-giant
HD 102272 with the Hobby-Eberly Telescope. In the absence of any correlation of
the observed periodicities with the standard indicators of stellar activity,
the observed radial velocity variations are most plausibly explained in terms
of a Keplerian motion of at least one planet-mass body around the star. With
the estimated stellar mass of 1.9M, the minimum mass of the confirmed
planet is 5.9M. The planet's orbit is characterized by a small but nonzero
eccentricity of =0.05 and the semi-major axis of 0.61 AU, which makes it the
most compact one discovered so far around GK-giants. This detection adds to the
existing evidence that, as predicted by theory, the minimum size of planetary
orbits around intermediate-mass giants is affected by both planet formation
processes and stellar evolution. The currently available evidence for another
planet around HD 102272 is insufficient to obtain an unambiguous two-orbit
solution.Comment: 10 pages, 5 figure
The Penn State - Toru\'n Planet Search: target characteristics and recent results
More than 450 stars hosting planets are known today but only approximately 30
planetary systems were discovered around stars beyond the Main Sequence. The
Penn State-Toru\'n Planet Search, putting an emphasis on extending studies of
planetary system formation and evolution to intermediate-mass stars, is
oriented towards the discoveries of substellar-mass companions to a large
sample of evolved stars using high-precision radial velocity technique. We
present the recent status of our survey and detailed characteristic for ~350
late type giant stars, i.e. the new results of radial velocity analysis and
stellar fundamental parameters obtained with extensive spectroscopic method.
Moreover, in the future we will make an attempt to perform the statistical
study of our sample and searching the correlations between the existence of
substellar objects and stellar atmospheric parameters according to previous
works which investigated the planetary companion impact on the evolution of the
host stars.Comment: 7 pages, 5 figures, proceeding of the conference "Planetary Systems
beyond the Main Sequence" (Bamberg, Germany, August 11-14, 2010) edited by S.
Schuh, H. Drechsel and U. Heber, AIP Conference Series, part of
PlanetsbeyondMS/2010 proceedings http://arxiv.org/html/1011.660
Planets Around the K-Giants BD+20 274 and HD 219415
We present the discovery of planet-mass companions to two giant stars by the
ongoing Penn State- Toru\'n Planet Search (PTPS) conducted with the 9.2 m
Hobby-Eberly Telescope. The less massive of these stars, K5-giant BD+20 274,
has a 4.2 MJ minimum mass planet orbiting the star at a 578-day period and a
more distant, likely stellar-mass companion. The best currently available model
of the planet orbiting the K0-giant HD 219415 points to a Jupiter-mass
companion in a 5.7-year, eccentric orbit around the star, making it the longest
period planet yet detected by our survey. This planet has an amplitude of
\sim18 m/s, comparable to the median radial velocity (RV) "jitter", typical of
giant stars.Comment: 5 figures, 13 pages, accepted by the Astrophysical Journal. arXiv
admin note: substantial text overlap with arXiv:1110.164
Is there a metallicity enhancement in planet hosting red giants?
The Penn State/Toru\'n Centre for Astronomy Search for Planets Around Evolved
Stars is a high-precision radial velocity (RV) survey aiming at planets
detection around giant stars. It is based on observations obtained with the 9.2
m Hobby-Eberly Telescope. As proper interpretation of high precision RV data
for red giants requires complete spectral analysis of targets we perform
spectral modeling of all stars included in the survey. Typically, rotation
velocities and metallicities are determined in addition to stellar luminosities
and temperatures what allows us to estimate stellar ages and masses. Here we
present preliminary results of metallicity studies in our sample. We search a
metallicity dependence similar to that for dwarfs by comparing our results for
a sample of 22 giants earlier than K5 showing significant RV variations with a
control sample of 58 relatively RV-stable stars.Comment: 5 pages, 2 figures. To appear in "Extrasolar Planets in Multi-body
Systems: Theory and Observations
Phenolic and Flavonoid Content in Hericium Erinaceus, Ganoderma Lucidum and Agrocybe Aegerita under Selenium Addition
The phenolic and flavonoid contents and composition and the antioxidant ability in Hericium erinaceus, Ganoderma lucidum, and Agrocybe aegerita under selenium (Se) addition to growth medium were studied. The contents of total Se in fruiting bodies of controls (0 mM of Se) were 4.58 (A. aegerita), 8.53 (G. lucidum), and 14.29 (H. erinaceus) mg kg–1 dry weight (DW), and was significantly increased by Se enrichment of substrate. The total phenolics in fruiting bodies of controls of H. erinaceus, G. lucidum, and A. aegerita were significantly lower (17.10, 28.11, and 16.05 mg of gallic acid equivalent (GAE)/g of extract, respectively) than for Se-rich mushrooms (26.29, 40.29, and 20.07 mg GAE/g of extract, respectively). Total flavonoid content for H. erinaceus, G. lucidum, and A. aegerita increased after Se supplementation from 368.6 to 445.6, 469.9 to 627.7, and 318.1 to 393.9 μg g–1 of extract, respectively. The results show that the mushrooms have superior antioxidant properties after Se addition, because the scavenging ability on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals was improved
A symptomatic pelvic rib
Pelvic rib is a rare anomaly where ectopic rib is found in a pelvic region. It is usually found occasionally in asymptomatic patients. We report a case of 15-year-old male, diagnosed with a symptomatic pelvic rib. It had an unusual presentation creating a pseudotumour associated with pain and reduced range of motion in the hip joint. Patient was operated on with good result and final diagnosis was confirmed in pathological examination. (Folia Morphol 2018; 77, 2: 406–408
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