6 research outputs found
Detection and Preliminary Characterisation of Polluted White Dwarfs from Gaia EDR3 and LAMOST
We present a catalogue of 62 polluted white dwarfs observed by the 9th
Low-Resolution Data Release of the Large Sky Area Multi-Object Fiber
Spectroscopic Telescope (LAMOST LRS DR9v1; R1,800) and the Early Data
Release 3 (EDR3) of the Gaia Mission. Among these stellar remnants, 30 are new
discoveries with previously unknown traces of calcium pollution. To generate
our catalogue, we used a database of 4,324 unique Gaia EDR3 white dwarf
candidates with LAMOST LRS DR9v1 observations, many of which have been
spectroscopically confirmed by other telescopes. For these stars, we developed
a quantitative method to detect calcium absorption in their spectra between
3,900-4,000, which we then validated through visual
inspection and multiple literature cross-checks. Our catalogue provides the
astrometric and photometric properties of the white dwarf candidates,
incorporates supplementary data (e.g. Montreal White Dwarf Database, MWDD;
PanSTARRS; the Hubble Space Telescope), and indicates the possibility of
calcium pollution in their atmospheres. For our final sample of polluted white
dwarfs, we also determine the main atmospheric properties of 23 sources with
effective temperatures 25,000K and no existing calcium
abundances in the MWDD. Our analysis represents a first step towards measuring
the full atmospheric composition of these stars and learning about the bulk
properties of their accreted material. As we venture into the era of wide-field
spectroscopic surveys, our work highlights the importance of combining
large-scale databases for identifying and characterising new polluted white
dwarfs.Comment: 29 pages, 14 figures (+3 in the Appendix), 5 tables (+5 in the
Appendix). Accepted for publication in MNRA
HD 219134 Revisited: Planet d Transit Upper Limit and Planet f Transit Nondetection with ASTERIA and TESS
HD 219134 is a K3V dwarf star with six reported radial-velocity discovered planets. The two innermost planets b and c show transits, raising the possibility of this system to be the nearest (6.53 pc), brightest (V = 5.57) example of a star with a compact multiple transiting planet system. Ground-based searches for transits of planets beyond b and c are not feasible because of the infrequent transits, long transit duration (~5 hr), shallow transit depths (<1%), and large transit time uncertainty (~half a day). We use the space-based telescopes the Arcsecond Space Telescope Enabling Research in Astrophysics (ASTERIA) and the Transiting Exoplanet Survey Satellite (TESS) to search for transits of planets f (P = 22.717 days and M sin i = 7.3 ± 0.04M_⊕) and d (P = 46.859 days and M sin i = 16.7 ± 0.64M_⊕). ASTERIA was a technology demonstration CubeSat with an opportunity for science in an extended program. ASTERIA observations of HD 219134 were designed to cover the 3σ transit windows for planets f and d via repeated visits over many months. While TESS has much higher sensitivity and more continuous time coverage than ASTERIA, only the HD 219134 f transit window fell within the TESS survey's observations. Our TESS photometric results definitively rule out planetary transits for HD 219134 f. We do not detect the Neptune-mass HD 219134 d transits and our ASTERIA data are sensitive to planets as small as 3.6 R_⊕. We provide TESS updated transit times and periods for HD 219134 b and c, which are designated TOI 1469.01 and 1469.02 respectively
HD 191939: Three Sub-Neptunes Transiting a Sun-like Star Only 54 pc Away
We present the discovery of three sub-Neptune-sized planets transiting the nearby and bright Sun-like star HD 191939 (TIC 269701147, TOI 1339), a K s = 7.18 mag G8 V dwarf at a distance of only 54 pc. We validate the planetary nature of the transit signals by combining 5 months of data from the Transiting Exoplanet Survey Satellite with follow-up ground-based photometry, archival optical images, radial velocities, and high angular resolution observations. The three sub-Neptunes have similar radii (Rb=3.42-0.11+0.11, Rc=3.23-0.11+0.11, and Rd=3.16-0.11+0.11,R⊕), and their orbits are consistent with a stable, circular, and coplanar architecture near mean-motion resonances of 1:3 and 3:4 (P b = 8.88, P c = 28.58, and P d = 38.35 days). The HD 191939 system is an excellent candidate for precise mass determinations of the planets with high-resolution spectroscopy due to the host star's brightness and low chromospheric activity. Moreover, the system's compact and near-resonant nature can provide an independent way to measure planetary masses via transit timing variations while also enabling dynamical and evolutionary studies. Finally, as a promising target for multiwavelength transmission spectroscopy of all three planets' atmospheres, HD 191939 can offer valuable insight into multiple sub-Neptunes born from a protoplanetary disk that may have resembled that of the early Sun.Funding for this research is provided by the Massachusetts
Institute of Technology, the MIT Torres Fellow Program, and the
MIT Kavli Institute. We acknowledge the use of public TESS
Alert data from pipelines at the TESS Science Office and the TESS
Science Processing Operations Center. Funding for the TESS
mission is provided by NASAʼs Science Mission directorate. This
research has made use of the Exoplanet Follow-up Observation
Program website, which is operated by the California Institute of
Technology, under contract with the National Aeronautics and
Space Administration under the Exoplanet Exploration Program.
Resources supporting this work were provided by the NASA
High-End Computing (HEC) Program through the NASA
Advanced Supercomputing (NAS) Division at Ames Research
Center for the production of the SPOC data products. This paper
includes data collected by the TESS mission that are publicly
available from the Mikulski Archive for Space Telescopes
(MAST). The STScI is operated by the Association of Universities
for Research in Astronomy, Inc., under NASA contract NAS
5-26555. This research has made use of the NASA Exoplanet
Archive, which is operated by the California Institute of
Technology, under contract with the National Aeronautics and
Space Administration under the Exoplanet Exploration Program.
The Digitized Sky Surveys were produced at the Space Telescope
Science Institute under U.S. Government grant NAG W-2166. The
images of these surveys are based on photographic data obtained
using the Oschin Schmidt Telescope on Palomar Mountain and the
UK Schmidt Telescope. The plates were processed into the present
compressed digital form with the permission of these institutions.
The National Geographic Society—Palomar Observatory Sky
Atlas (POSS-I) was made by the California Institute of Technology
with grants from the National Geographic Society. The Second
Palomar Observatory Sky Survey (POSS-II) was made by the
California Institute of Technology with funds from the National
Science Foundation, the National Geographic Society, the Sloan
Foundation, the Samuel Oschin Foundation, and the Eastman
Kodak Corporation. This work has made use of data from the
European Space Agency (ESA) mission Gaia (https://www.
cosmos.esa.int/gaia), processed by the Gaia Data Processing and
Analysis Consortium (DPAC; https://www.cosmos.esa.int/web/
gaia/dpac/consortium). Funding for the DPAC has been provided
by national institutions, in particular the institutions participating in
the Gaia Multilateral Agreement. This paper used data retrieved
from the SOPHIE archive at Observatoire de Haute-Provence
(OHP), available at atlas.obs-hp.fr/sophie. The AO images
presented in this paper were obtained at the Gemini Observatory
(Program ID: GN-2019B-LP-101), which is operated by the Association of Universities for Research in Astronomy, Inc., under
a cooperative agreement with the NSF on behalf of the Gemini
partnership: the National Science Foundation (United States),
National Research Council (Canada), CONICYT (Chile), Ministerio de Ciencia, TecnologÃa e Innovación Productiva (Argentina),
Ministério da Ciência, Tecnologia e Inovação (Brazil), and Korea
Astronomy and Space Science Institute (Republic of Korea).
The authors thank Amanda Bosh (MIT), Tim Brothers (MIT
Wallace Astrophysical Observatory), Julien de Wit (MIT),
Artem Burdanov (MIT), Songhu Wang (Yale University),
Enrique Herrero (IEEC/OAdM), Jonathan Irwin (HarvardCfA), Samuel Hadden (Harvard-CfA), Özgür Baştürk (Ankara
University), Ergün Ege (Istanbul University), and Brice-Olivier
Demory (University of Bern) for helping to coordinate followup observations.
We thank the anonymous referee for helpful comments
and suggestions that greatly improved this work. M.N.G. and
C.X.H. acknowledge support from MIT’s Kavli Institute as
Juan Carlos Torres Fellows. T.D. acknowledges support from
MITʼs Kavli Institute as a Kavli postdoctoral fellow. A.V.ʼs
work was performed under contract with the California Institute
of Technology/Jet Propulsion Laboratory, funded by NASA
through the Sagan Fellowship Program executed by the NASA
Exoplanet Science Institute. I.R. acknowledges support from
the Spanish Ministry of Science, Innovation and Universities
(MCIU) and the Fondo Europeo de Desarrollo Regional
(FEDER) through grant PGC2018-098153-B-C33, as well as
the support of the Generalitat de Catalunya/CERCA program.
B.V.R. and J.N.W. thank the Heising-Simons Foundation for
support. I.J.M.C. acknowledges support from the NSF through
grant AST-1824644 and NASA through Caltech/JPL grant
RSA-1610091
Hide your pain:Social threat increases pain reports and aggression, but reduces facial pain expression and empathy
Earlier research studying the effects of social threat on the experience and expression of pain led to mixed results. In this study, female participants (N = 32) came to the lab with two confederates. Both confederates administered a total of 10 painful electrocutaneous stimuli to the participant. The framing of the administration was manipulated in a within-subjects design: In the low social threat condition the participant was told that the confederate could choose between 10 to 20 pain stimuli, thus they believed that this confederate chose to administer the minimum allowed number of pain stimuli. In the high social threat condition the confederate had a choice between 1 and 10 stimuli, thus they believed that this confederate chose to administer the maximum allowed number of stimuli. Participants reported on the intensity, unpleasantness, and threat value of the painful stimuli, and their facial expression was recorded. Moreover, aggression and empathy towards the confederates were assessed. As hypothesized, participants reported increased pain intensity, unpleasantness, and threat in the high social threat condition compared to the low social threat condition, but showed less facial pain expression. Finally, participants exhibited increased aggression and reduced empathy towards the confederate in the high social threat condition.status: publishe
Breed concept van deelname met smalle strafschaal
status: publishe