71 research outputs found
HAT-P-7: A Retrograde or Polar Orbit, and a Third Body
We show that the exoplanet HAT-P-7b has an extremely tilted orbit, with a
true angle of at least 86 degrees with respect to its parent star's equatorial
plane, and a strong possibility of retrograde motion. We also report evidence
for an additional planet or companion star. The evidence for the unparalleled
orbit and the third body is based on precise observations of the star's
apparent radial velocity. The anomalous radial velocity due to rotation (the
Rossiter-McLaughlin effect) was found to be a blueshift during the first half
of the transit and a redshift during the second half, an inversion of the usual
pattern, implying that the angle between the sky-projected orbital and stellar
angular momentum vectors is 182.5 +/- 9.4 degreees. The third body is
implicated by excess radial-velocity variation of the host star over 2 yr. Some
possible explanations for the tilted orbit are a close encounter with another
planet, the Kozai effect, and resonant capture by an inward-migrating outer
planet.Comment: ApJ Letters, in press [7 pages
Childcare in England : parental motivations for use, decision-making and perceptions of quality : a qualitative study : May 2023
Archaeal and bacterial metagenome-assembled genome sequences derived from pig feces
We report the recovery of metagenome-assembled genomes (MAGs) from fecal samples collected in 2018 from five healthy adult female pigs in southeast England. The resulting nonredundant catalog of 192 MAGs encompasses 102 metagenomic species, 41 of them novel, spanning 10 bacterial and 2 archaeal phyla
The Transit Ingress and the Tilted Orbit of the Extraordinarily Eccentric Exoplanet HD 80606b
We present the results of a transcontinental campaign to observe the 2009
June 5 transit of the exoplanet HD 80606b. We report the first detection of the
transit ingress, revealing the transit duration to be 11.64 +/- 0.25 hr and
allowing more robust determinations of the system parameters. Keck spectra
obtained at midtransit exhibit an anomalous blueshift, giving definitive
evidence that the stellar spin axis and planetary orbital axis are misaligned.
The Keck data show that the projected spin-orbit angle is between 32-87 deg
with 68.3% confidence and between 14-142 deg with 99.73% confidence. Thus the
orbit of this planet is not only highly eccentric (e=0.93), but is also tilted
away from the equatorial plane of its parent star. A large tilt had been
predicted, based on the idea that the planet's eccentric orbit was caused by
the Kozai mechanism. Independently of the theory, it is noteworthy that all 3
exoplanetary systems with known spin-orbit misalignments have massive planets
on eccentric orbits, suggesting that those systems migrate differently than
lower-mass planets on circular orbits.Comment: ApJ, in press [13 pg
Warm ice giant GJ 3470b - II. Revised planetary and stellar parameters from optical to near-infrared transit photometry
It is important to explore the diversity of characteristics of low-mass, low-density planets to understand the nature and evolution of this class of planets. We present a homogeneous analysis of 12 new and 9 previously published broad-band photometric observations of the Uranus-sized extrasolar planet GJ 3470b, which belongs to the growing sample of sub-Jovian bodies orbiting M dwarfs. The consistency of our analysis explains some of the discrepancies between previously published results and provides updated constraints on the planetary parameters. Our data are also consistent with previous transit observations of this system. The physical properties of the transiting system can only be constrained as well as the host star is characterized, so we provide new spectroscopic measurements of GJ 3470 from 0.33 to 2.42 μm to aid our analysis. We find R* = 0.48 ± 0.04 R⊙, M* = 0.51 ± 0.06 M⊙, and T_(eff) = 3652 ± 50K for GJ 3470, along with a rotation period of 20.70 ± 0.15 d and an R-band amplitude of 0.01 mag, which is small enough that current transit measurements should not be strongly affected by stellar variability. However, to report definitively whether stellar activity has a significant effect on the light curves, this requires future multiwavelength, multi-epoch studies of GJ 3470. We also present the most precise orbital ephemeris for this system: To = 2455983.70472 ± 0.00021BJD_(TDB), P = 3.336 6487^(+0.0000043)_(−0.0000033)
 d, and we see no evidence for transit timing variations greater than 1 min. Our reported planet to star radius ratio is 0.076 42 ± 0.000 37. The physical parameters of this planet are R_p = 3.88 ± 0.32 R⊕ and M_p = 13.73 ± 1.61 M⊕. Because of our revised stellar parameters, the planetary radius we present is smaller than previously reported values. We also perform a second analysis of the transmission spectrum of the entire ensemble of transit observations to date, supporting the existence of an H_2-dominated atmosphere exhibiting a strong Rayleigh scattering slope
Patient survey examining the experience of care of a hospital-based opt-out tobacco dependency treatment service (the CURE Project)
INTRODUCTION: Treating tobacco dependency in patients admitted to hospital is a key priority in the National Health Service long-term plan. This service evaluation assessed the perception, needs and experience of care within an opt-out hospital-based tobacco dependency treatment service (the Conversation, Understand, Replace, Experts and Evidence Base (CURE) team) in North-West England. METHODS: A survey was offered to all eligible patients between 1 July 2020 and 30 September 2020. Eligibility criteria were adult patients identified as an active smoker being approached by the CURE team as part of the standard opt-out service model, on a non-covid ward without a high suspicion of COVID-19 infection and able to read and write in English. RESULTS: 106 completed surveys were evaluated. Participants demonstrated high levels of tobacco dependency with an average of 37 years smoking history and 66% describing the onset of cravings within 30 min of hospital admission. The average number quit attempts in the previous 12 months was 1.3 but only 9% had used the most effective National Institute for Health and Care Excellence (NICE) recommended treatments. 100% felt the opt-out service model was appropriate and 96% stated the treatment and support they had received had prompted them to consider a further quit attempt. 82% of participants rated their experience of care as 9/10 or 10/10. Participants wanted a broad range of support post discharge with the most popular option being with their general practitioner. 66% and 65% of participants would have been interested in a vaping kit as stop smoking intervention and support vaping-friendly hospital grounds respectively. CONCLUSION: These results suggest this hospital-based, opt-out tobacco dependency treatment service delivers high-quality experience of care and meets the needs of the patients it serves. It also highlights the opportunity to enhance outcomes by providing access to NICE recommended most-effective interventions (varenicline, vaping and combination nicotine replacement therapy) and providing flexible, individualised discharge pathways
<i>TESS</i> Spots a Compact System of Super-Earths around the Naked-eye Star HR 858
Transiting Exoplanet Survey Satellite (TESS) observations have revealed a compact multiplanet system around the sixth-magnitude star HR 858 (TIC 178155732, TOI 396), located 32 pc away. Three planets, each about twice the size of Earth, transit this slightly evolved, late F-type star, which is also a member of a visual binary. Two of the planets may be in mean motion resonance. We analyze the TESS observations, using novel methods to model and remove instrumental systematic errors, and combine these data with follow-up observations taken from a suite of ground-based telescopes to characterize the planetary system. The HR 858 planets are enticing targets for precise radial velocity observations, secondary eclipse spectroscopy, and measurements of the Rossiter–McLaughlin effect
A planet within the debris disk around the pre-main-sequence star AU Microscopii
AU Microscopii (AU Mic) is the second closest pre main sequence star, at a
distance of 9.79 parsecs and with an age of 22 million years. AU Mic possesses
a relatively rare and spatially resolved3 edge-on debris disk extending from
about 35 to 210 astronomical units from the star, and with clumps exhibiting
non-Keplerian motion. Detection of newly formed planets around such a star is
challenged by the presence of spots, plage, flares and other manifestations of
magnetic activity on the star. Here we report observations of a planet
transiting AU Mic. The transiting planet, AU Mic b, has an orbital period of
8.46 days, an orbital distance of 0.07 astronomical units, a radius of 0.4
Jupiter radii, and a mass of less than 0.18 Jupiter masses at 3 sigma
confidence. Our observations of a planet co-existing with a debris disk offer
the opportunity to test the predictions of current models of planet formation
and evolution.Comment: Nature, published June 24th [author spelling name fix
Early Release Science of the exoplanet WASP-39b with JWST NIRCam
Measuring the metallicity and carbon-to-oxygen (C/O) ratio in exoplanet
atmospheres is a fundamental step towards constraining the dominant chemical
processes at work and, if in equilibrium, revealing planet formation histories.
Transmission spectroscopy provides the necessary means by constraining the
abundances of oxygen- and carbon-bearing species; however, this requires broad
wavelength coverage, moderate spectral resolution, and high precision that,
together, are not achievable with previous observatories. Now that JWST has
commenced science operations, we are able to observe exoplanets at previously
uncharted wavelengths and spectral resolutions. Here we report time-series
observations of the transiting exoplanet WASP-39b using JWST's Near InfraRed
Camera (NIRCam). The long-wavelength spectroscopic and short-wavelength
photometric light curves span 2.0 - 4.0 m, exhibit minimal systematics,
and reveal well-defined molecular absorption features in the planet's spectrum.
Specifically, we detect gaseous HO in the atmosphere and place an upper
limit on the abundance of CH. The otherwise prominent CO feature at 2.8
m is largely masked by HO. The best-fit chemical equilibrium models
favour an atmospheric metallicity of 1-100 solar (i.e., an enrichment
of elements heavier than helium relative to the Sun) and a sub-stellar
carbon-to-oxygen (C/O) ratio. The inferred high metallicity and low C/O ratio
may indicate significant accretion of solid materials during planet formation
or disequilibrium processes in the upper atmosphere.Comment: 35 pages, 13 figures, 3 tables, Nature, accepte
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