New binaries from the SHINE survey Bonavita, M.; Gratton, R.; Desidera, S. ...
Astronomy and astrophysics (Berlin),
07/2022, Volume:
663
Journal Article, Web Resource
Peer reviewed
Open access
We present the multiple stellar systems observed within the SpHere INfrared survey for Exoplanet (SHINE). SHINE searched for sub-stellar companions to young stars using high contrast imaging. ...Although stars with known stellar companions within the SPHERE field of view (< 5.5 arcsec) were removed from the original target list, we detected additional stellar companions to 78 of the 463 SHINE targets observed so far. Twenty-seven per cent of the systems have three or more components. Given the heterogeneity of the sample in terms of observing conditions and strategy, tailored routines were used for data reduction and analysis, some of which were specifically designed for these datasets. We then combined SPHERE data with literature and archival data, TESS light curves, and
Gaia
parallaxes and proper motions for an accurate characterisation of the systems. Combining all data, we were able to constrain the orbits of 25 systems. We carefully assessed the completeness of our sample for separations between 50–500 mas (corresponding to periods of a few years to a few decades), taking into account the initial selection biases and recovering part of the systems excluded from the original list due to their multiplicity. This allowed us to compare the binary frequency for our sample with previous studies and highlight interesting trends in the mass ratio and period distribution. We also found that, when such an estimate was possible, the values of the masses derived from dynamical arguments were in good agreement with the model predictions. Stellar and orbital spins appear fairly well aligned for the 12 stars that have enough data, which favours a disk fragmentation origin. Our results highlight the importance of combining different techniques when tackling complex problems such as the formation of binaries and show how large samples can be useful for more than one purpose.
Aims.
We present new optical and near-infrared images of the debris disk around the F-type star HD 114082 in the Scorpius-Centaurus OB association. We obtained direct imaging observations and ...analyzed the TESS photometric time series data of this target with the goal of searching for planetary companions to HD 114082 and characterizing the morphology of the debris disk and the scattering properties of dust particles.
Methods.
HD 114082 was observed with the VLT/SPHERE instrument in different modes – the IRDIS camera in the
K
band (2.0–2.3 μm) together with the IFS in the
Y
,
J
, and
H
bands (0.95–1.66 μm) using the angular differential imaging technique as well as IRDIS in the
H
band (1.5–1.8 μm) and ZIMPOL in the I_PRIME band (0.71–0.87 μm) using the polarimetric differential imaging technique. To constrain the basic geometrical parameters of the disk and the scattering properties of dust grains, scattered light images were fitted with a 3D model for single scattering in an optically thin dust disk using a Markov chain Monte Carlo approach. We performed aperture photometry to derive the scattering and polarized phase functions, the polarization fraction, and the spectral scattering albedo for the dust particles in the disk. This method was also used to obtain the reflectance spectrum of the disk and, in turn, to retrieve the disk color and study the dust reflectivity in comparison to the debris disk HD 117214. We also performed the modeling of the HD 114082 light curve measured by TESS using models for planet transit and stellar activity to put constraints on the radius of the detected planet and its orbit. Last, we searched for additional planets in the system by combining archival radial velocity data, astrometry, and direct imaging.
Results.
The debris disk HD 114082 appears as an axisymmetric debris belt with a radius of ~0.37″ (35 au), an inclination of ~83°, and a wide inner cavity. Dust particles in HD 114082 have a maximum polarization fraction of ~17% and a higher reflectivity when compared to the debris disk HD 117214. This high reflectivity results in a spectral scattering albedo of ~0.65 for the HD 114082 disk at near-infrared wavelengths. The disk reflectance spectrum exhibits a red color at the position of the planetesimal belt and shows no obvious features, whereas that of HD 117214 might indicate the presence of CO
2
ice. The analysis of TESS photometric data reveals a transiting planetary companion to HD 114082 with a radius of ~1
R
Jup
on an orbit with a semimajor axis of 0.7 ± 0.4 au. No additional planet was detected in the system when we combined the SPHERE images with constraints from astrometry and radial velocity. We reach deep sensitivity limits down to ~5
M
Jup
at 50 au and ~10
M
Jup
at 30 au from the central star.
Aims. We present new optical and near-infrared images of the debris disk around the F-type star HD 114082 in the Scorpius-Centaurus OB association. We obtained direct imaging observations and ...analyzed the TESS photometric time series data of this target with the goal of searching for planetary companions to HD 114082 and characterizing the morphology of the debris disk and the scattering properties of dust particles. Methods. HD 114082 was observed with the VLT/SPHERE instrument in different modes – the IRDIS camera in the K band (2.0–2.3 μm) together with the IFS in the Y, J, and H bands (0.95–1.66 μm) using the angular differential imaging technique as well as IRDIS in the H band (1.5–1.8 μm) and ZIMPOL in the I_PRIME band (0.71–0.87 μm) using the polarimetric differential imaging technique. To constrain the basic geometrical parameters of the disk and the scattering properties of dust grains, scattered light images were fitted with a 3D model for single scattering in an optically thin dust disk using a Markov chain Monte Carlo approach. We performed aperture photometry to derive the scattering and polarized phase functions, the polarization fraction, and the spectral scattering albedo for the dust particles in the disk. This method was also used to obtain the reflectance spectrum of the disk and, in turn, to retrieve the disk color and study the dust reflectivity in comparison to the debris disk HD 117214. We also performed the modeling of the HD 114082 light curve measured by TESS using models for planet transit and stellar activity to put constraints on the radius of the detected planet and its orbit. Last, we searched for additional planets in the system by combining archival radial velocity data, astrometry, and direct imaging. Results. The debris disk HD 114082 appears as an axisymmetric debris belt with a radius of ~0.37″ (35 au), an inclination of ~83°, and a wide inner cavity. Dust particles in HD 114082 have a maximum polarization fraction of ~17% and a higher reflectivity when compared to the debris disk HD 117214. This high reflectivity results in a spectral scattering albedo of ~0.65 for the HD 114082 disk at near-infrared wavelengths. The disk reflectance spectrum exhibits a red color at the position of the planetesimal belt and shows no obvious features, whereas that of HD 117214 might indicate the presence of CO2 ice. The analysis of TESS photometric data reveals a transiting planetary companion to HD 114082 with a radius of ~1 RJup on an orbit with a semimajor axis of 0.7 ± 0.4 au. No additional planet was detected in the system when we combined the SPHERE images with constraints from astrometry and radial velocity. We reach deep sensitivity limits down to ~5 MJup at 50 au and ~10 MJup at 30 au from the central star.
Recent observations of resolved cold debris discs at tens of au have revealed that gaps could be a common feature in these Kuiper-belt analogues. Such gaps could be evidence for the presence of ...planets within the gaps or closer in near the edges of the disc. We present SPHERE observations of HD 92945 and HD 107146, two systems with detected gaps. We constrained the mass of possible companions responsible for the gap to 1–2 M Jup for planets located inside the gap and to less than 5 M Jup for separations down to 20 au from the host star. These limits allow us to exclude some of the possible configurations of the planetary systems proposed to explain the shape of the discs around these two stars. In order to put tighter limits on the mass at very short separations from the star, where direct-imaging data are less effective, we also combined our data with astrometric measurements from Hipparcos and Gaia and radial-velocity measurements. We were able to limit the separation and the mass of the companion potentially responsible for the proper-motion anomaly of HD 107146 to values of 2–7 au and 2–5 M Jup , respectively.
This study examined the effect of information source on students' estimates of academic dishonesty. Undergraduates read an estimate of the incidence of academic dishonesty. Half of the participants ...were told that the source was a professor’s study and the other half heard that the source was a student’s study. Participants then estimated the likelihood that they, their friends, and the average college student would plagiarize or cheat on tests. Results indicated that when the source of the statistic was a professor, students were more likely to provide estimates of cheating and plagiarism that more closely approximated the provided statistic. The authors discuss how these findings might be used to enhance social norms campaign efforts.
Carbon doping of silicon is a subject of high interest since at high concentration (>
1×10
18
cm
−3
), carbon can reduce or even suppress the undesirable diffusion of boron in silicon-based bipolar ...transistors. To understand this macroscopic behavior, processes of point defect interactions (i.e. between dopants, vacancies and self-interstitials) have to be analyzed. The reduction of the boron diffusion by carbon is known to be due to the creation of a self-interstitial undersaturation. In this work we discuss the influence of the oversaturation of vacancies also produced by a high carbon concentration during annealing. Experiments with a vacancy diffusing dopant, antimony, are demonstrated to prove this effect: in a carbon rich sample, the antimony diffusion is enhanced about eight times compared to samples with a much lower carbon concentration. We also investigate the carbon co-precipitation with oxygen. We explain this affinity by an exchange of point defects and a volume compensation.
Seventy-five women, of whom 30 had received postoperative radiotherapy, were tested for range of motion (ROM) and shoulder strength with a goniometer and an isokinetic device (Orthotron II), ...respectively. On the individual level, irradiated patients exhibited significantly reduced range of motion (varying from p<0.05 to p<0.001) for all movements compared with the non-operated side. In contrast, in the non-irradiated patients only flexion was significantly reduced (p<0.05). The same individual pattern was evident for shoulder strength where all movements except external rotation were significantly reduced in irradiated patients (varying from p<0.05 to p<0.001). Non-irradiated patients exhibited a significant reduction in shoulder strength for flexion and abduction (p<0.05), whereas other movements were less affected. The observed differences in ROM and strength were less pronounced when analyzed on a group level, but were still significant for ROM (p<0.001) for flexion and abduction. Group level analysis also showed reduced shoulder strength for all movements but only rotation was significantly (p<0.01) impaired.
Context. R Aqr is a symbiotic binary system consisting of a mira variable, a hot companion with a spectacular jet outflow, and an extended emission line nebula. Because of its proximity to the Sun, ...this object has been studied in much detail with many types of high resolution imaging and interferometric techniques. We have used R Aqr as test target for the visual camera subsystem ZIMPOL, which is part of the new extreme adaptive optics (AO) instrument SPHERE at the Very Large Telescope (VLT). Aims. We describe SPHERE /ZIMPOL test observations of the R Aqr system taken in H alpha and other filters in order to demonstrate the exceptional performance of this high resolution instrument. We compare our observations with data from the Hubble Space Telescope (HST) and illustrate the complementarity of the two instruments. We use our data for a detailed characterization of the inner jet region of R Aqr. Methods. We analyze the high resolution approximate to 25 mas images from SPHERE /ZIMPOL and determine from the H alpha emission the position, size, geometric structure, and line fluxes of the jet source and the clouds in the innermost region <2 `' (< 400 AU) of R Aqr. The data are compared to simultaneous HST line filter observations. The H alpha fluxes and the measured sizes of the clouds yield H alpha emissivities for many clouds from which one can derive the mean density, mass, recombination time scale, and other cloud parameters. Results. Our H alpha data resolve for the first time the R Aqr binary and we measure for the jet source a relative position 45 mas West (position angle ‐89.5 degrees) of the mira. The central jet source is the strongest H alpha component with a flux of about 2.5 x 10(‐12) erg cm(‐2) s(‐1). North east and south west from the central source there are many clouds with very diverse structures. Within 0.5 `' (100 AU) we see in the SW a string of bright clouds arranged in a zig‐zag pattern and, further out, at 1 `'‐2 `', fainter and more extended bubbles. In the N and NE we see a bright, very elongated filamentary structure between 0.2 `'‐0.7 `' and faint perpendicular `` wisps'' further out. Some jet clouds are also detected in the ZIMPOL O I and He I filters, as well as in the HST‐WFC3 line filters for H alpha, O III, N II, and O I. We determine jet cloud parameters and find a very well defined correlation N‐e proportional to r(‐1.3) between cloud density and distance to the central binary. Densities are very high with typical values of N‐e approximate to 3 x 10(5) cm(‐3) for the ``outer'' clouds around 300 AU, N‐e approximate to 3 x 10(6) cm(‐3) for the ``inner'' clouds around 50 AU, and even higher for the central jet source. The high Ne of the clouds implies short recombination or variability timescales of a year or shorter. Conclusions. H alpha high resolution data provide a lot of diagnostic information for the ionized jet gas in R Aqr. Future H alpha observations will provide the orientation of the orbital plane of the binary and allow detailed hydrodynamical investigations of this jet outflow and its interaction with the wind of the red giant companion.
The relationship between separation-individuation and identity development was investigated in a sample of runaway/homeless adolescents (N = 83). Participants were 18-21 years (M = 19.4, SD = 0.86). ...The ethnic distribution consisted of 50.6% African American, 24.1% European American, 18.1% Hispanic American and 7.2% Other. Participants provided demographic information and completed the Separation Individuation Test of Adolescence (SITA) and the Ego Identity Process Questionnaire. The hypotheses that Healthy Separation (one of the nine SITA variables) would predict Identity Exploration and Identity Commitment were not supported. Hierarchical regression analyses yielded only one statistically significant finding: Practicing Mirroring (a SITA subscale that measures narcissistic self-confidence derived from feedback from others) predicted Identity Commitment scores. These results support the importance of caregiver encouragement during the identity development process. Consideration of the separation- individuation process in this population and its role in identity development are reviewed as implications for intervention within out-of-home placements.
ABSTRACT LkCa 15 hosts a pre-transitional disk as well as at least one accreting protoplanet orbiting in its gap. Previous disk observations have focused mainly on the outer disk, which is cleared ...inward of ∼50 au. The planet candidates, on the other hand, reside at orbital radii around 15 au, where disk observations have been unreliable until recently. Here, we present new J-band imaging polarimetry of LkCa 15 with SPHERE IRDIS, yielding the most accurate and detailed scattered-light images of the disk to date down to the planet-hosting inner regions. We find what appear to be persistent asymmetric structures in the scattering material at the location of the planet candidates, which could be responsible at least for parts of the signals measured with sparse-aperture masking. These images further allow us to trace the gap edge in scattered light at all position angles and search the inner and outer disks for morphological substructure. The outer disk appears smooth with slight azimuthal variations in polarized surface brightness, which may be due to shadowing from the inner disk or a two-peaked polarized phase function. We find that the near-side gap edge revealed by polarimetry matches the sharp crescent seen in previous ADI imaging very well. Finally, the ratio of polarized disk to stellar flux is more than six times larger in the J-band than in the RI bands.
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