Abstract
We present a novel machine-learning approach for detecting faint point sources in high-contrast adaptive optics (AO) imaging data sets. The most widely used algorithms for primary ...subtraction aim to decouple bright stellar speckle noise from planetary signatures by subtracting an approximation of the temporally evolving stellar noise from each frame in an imaging sequence. Our approach aims to improve the stellar noise approximation and increase the planet detection sensitivity by leveraging deep learning in a novel direct imaging post-processing algorithm. We show that a convolutional autoencoder neural network, trained on an extensive reference library of real imaging sequences, accurately reconstructs the stellar speckle noise at the location of a potential planet signal. This tool is used in a post-processing algorithm we call Direct Exoplanet Detection with Convolutional Image Reconstruction, or
ConStruct
. The reliability and sensitivity of
ConStruct
are assessed using real Keck/NIRC2 angular differential imaging data sets. Of the 30 unique point sources we examine,
ConStruct
yields a higher signal-to-noise ratio than traditional principal component analysis-based processing for 67% of the cases and improves the relative contrast by up to a factor of 2.6. This work demonstrates the value and potential of deep learning to take advantage of a diverse reference library of point-spread function realizations to improve direct imaging post-processing.
ConStruct
and its future improvements may be particularly useful as tools for post-processing high-contrast images from JWST and extreme AO instruments, both for the current generation and those being designed for the upcoming 30 m class telescopes.
Abstract
We present the direct-imaging discovery of a giant planet orbiting the young star AF Lep, a 1.2
M
⊙
member of the 24 ± 3 Myr
β
Pic moving group. AF Lep was observed as part of our ongoing ...high-contrast imaging program targeting stars with astrometric accelerations between Hipparcos and Gaia that indicate the presence of substellar companions. Keck/NIRC2 observations in
L
′
with the vector vortex coronagraph reveal a point source, AF Lep b, at ≈340 mas, which exhibits orbital motion at the 6
σ
level over the course of 13 months. A joint orbit fit yields precise constraints on the planet’s dynamical mass of
3.2
−
0.6
+
0.7
M
Jup
, semimajor axis of
8.4
−
1.3
+
1.1
au, and eccentricity of
0.24
−
0.15
+
0.27
. AF Lep hosts a debris disk located at ∼50 au, but it is unlikely to be sculpted by AF Lep b, implying there may be additional planets in the system at wider separations. The stellar inclination (
i
*
=
54
−
9
+
11
°
) and orbital inclination (
i
o
=
50
−
12
+
9
°
) are in good agreement, which is consistent with the system having spin–orbit alignment. AF Lep b is the lowest-mass imaged planet with a dynamical mass measurement and highlights the promise of using astrometric accelerations as a tool to find and characterize long-period planets.
Modern astronautics problems require methods of tractable uncertainty quantification for problems with data in a variety of mathematical spaces. Polynomial Chaos Expansions (PCEs) enable tractable ...uncertainty propagation, sensitivity analysis, and provide a surrogate model to efficiently solve stochastic optimization problems. Existing PCE methods are mostly isolated to bases defined via tensor products of univariate functions over subdomains of the real line or integers. The goal of this work is to incorporate random vectors on the
n
-dimensional sphere, thereby extending the use of PCEs to problems that include spacecraft attitude uncertainty. Random inputs with probability densities on the
n
-sphere are generally correlated. When directional random inputs are independent, products of univariate functions fail to produce an orthogonal basis. Basis functions must preserve the periodic response of the system produced by the underlying structure of the domain. This paper presents an approach to generating an orthogonal basis with respect to a density function on the
n
-sphere by combining hyperspherical harmonics with an orthogonalization procedure based on the raw moments of the harmonic functions. For highly concentrated densities on the unit sphere, the spherical cap harmonics provide a more numerically stable solution while preserving periodicity. Numeric errors in the proposed procedure are presented for multiple cases. Performance of the PCEs is quantified when propagating uncertainty for a highly eccentric orbit with a random translational maneuver error, and a second case based on rigid-body dynamics with the attitude state parameterized as a quaternion.
We present a novel machine-learning approach for detecting faint point sources in high-contrast adaptive optics imaging datasets. The most widely used algorithms for primary subtraction aim to ...decouple bright stellar speckle noise from planetary signatures by subtracting an approximation of the temporally evolving stellar noise from each frame in an imaging sequence. Our approach aims to improve the stellar noise approximation and increase the planet detection sensitivity by leveraging deep learning in a novel direct imaging post-processing algorithm. We show that a convolutional autoencoder neural network, trained on an extensive reference library of real imaging sequences, accurately reconstructs the stellar speckle noise at the location of a potential planet signal. This tool is used in a post-processing algorithm we call Direct Exoplanet Detection with Convolutional Image Reconstruction, or ConStruct. The reliability and sensitivity of ConStruct are assessed using real Keck/NIRC2 angular differential imaging datasets. Of the 30 unique point sources we examine, ConStruct yields a higher S/N than traditional PCA-based processing for 67\(\%\) of the cases and improves the relative contrast by up to a factor of 2.6. This work demonstrates the value and potential of deep learning to take advantage of a diverse reference library of point spread function realizations to improve direct imaging post-processing. ConStruct and its future improvements may be particularly useful as tools for post-processing high-contrast images from the James Webb Space Telescope and extreme adaptive optics instruments, both for the current generation and those being designed for the upcoming 30 meter-class telescopes.
With a dynamical mass of $3 \, M_\mathrm{Jup}$, the recently discovered giant
planet AF Lep b is the lowest-mass imaged planet with a direct mass
measurement. Its youth and spectral type near the L/T ...transition make it a
promising target to study the impact of clouds and atmospheric chemistry at low
surface gravities. In this work, we present JWST/NIRCam imaging of AF Lep b.
Across two epochs, we detect AF Lep b in F444W ($4.4 \, \mathrm{\mu m}$) with
S/N ratios of 9.6 and 8.7, respectively. At the planet's separation of $320 \,
\mathrm{mas}$ during the observations, the coronagraphic throughput is
${\approx}7\%$, demonstrating that NIRCam's excellent sensitivity persists down
to small separations. The F444W photometry of AF Lep b affirms the presence of
disequilibrium carbon chemistry and enhanced atmospheric metallicity. These
observations also place deep limits on wider-separation planets in the system,
ruling out $1.1 \, M_\mathrm{Jup}$ planets beyond $15.6 \, \mathrm{au}$ (0.58
arcsec), $1.1 \, M_\mathrm{Sat}$ planets beyond $27 \, \mathrm{au}$ (1 arcsec),
and $2.8 \, M_\mathrm{Nep}$ planets beyond $67 \, \mathrm{au}$ (2.5 arcsec). We
also present new Keck/NIRC2 $L'$ imaging of AF Lep b; combining this with the
two epochs of F444W photometry and previous Keck $L'$ photometry provides
limits on the long-term 3-$5 \, \mathrm{\mu m}$ variability of AF Lep b on
months-to-years timescales. AF Lep b is the closest-separation planet imaged
with JWST to date, demonstrating that planets can be recovered well inside the
nominal (50% throughput) NIRCam coronagraph inner working angle.
With a dynamical mass of \(3 \, M_\mathrm{Jup}\), the recently discovered giant planet AF Lep b is the lowest-mass imaged planet with a direct mass measurement. Its youth and spectral type near the ...L/T transition make it a promising target to study the impact of clouds and atmospheric chemistry at low surface gravities. In this work, we present JWST/NIRCam imaging of AF Lep b. Across two epochs, we detect AF Lep b in F444W (\(4.4 \, \mathrm{\mu m}\)) with S/N ratios of 9.6 and 8.7, respectively. At the planet's separation of \(320 \, \mathrm{mas}\) during the observations, the coronagraphic throughput is \({\approx}7\%\), demonstrating that NIRCam's excellent sensitivity persists down to small separations. The F444W photometry of AF Lep b affirms the presence of disequilibrium carbon chemistry and enhanced atmospheric metallicity. These observations also place deep limits on wider-separation planets in the system, ruling out \(1.1 \, M_\mathrm{Jup}\) planets beyond \(15.6 \, \mathrm{au}\) (0.58 arcsec), \(1.1 \, M_\mathrm{Sat}\) planets beyond \(27 \, \mathrm{au}\) (1 arcsec), and \(2.8 \, M_\mathrm{Nep}\) planets beyond \(67 \, \mathrm{au}\) (2.5 arcsec). We also present new Keck/NIRC2 \(L'\) imaging of AF Lep b; combining this with the two epochs of F444W photometry and previous Keck \(L'\) photometry provides limits on the long-term 3-\(5 \, \mathrm{\mu m}\) variability of AF Lep b on months-to-years timescales. AF Lep b is the closest-separation planet imaged with JWST to date, demonstrating that planets can be recovered well inside the nominal (50% throughput) NIRCam coronagraph inner working angle.
Most candidate drugs currently fail later-stage clinical trials, largely due to poor prediction of efficacy on early target selection
. Drug targets with genetic support are more likely to be ...therapeutically valid
, but the translational use of genome-scale data such as from genome-wide association studies for drug target discovery in complex diseases remains challenging
. Here, we show that integration of functional genomic and immune-related annotations, together with knowledge of network connectivity, maximizes the informativeness of genetics for target validation, defining the target prioritization landscape for 30 immune traits at the gene and pathway level. We demonstrate how our genetics-led drug target prioritization approach (the priority index) successfully identifies current therapeutics, predicts activity in high-throughput cellular screens (including L1000, CRISPR, mutagenesis and patient-derived cell assays), enables prioritization of under-explored targets and allows for determination of target-level trait relationships. The priority index is an open-access, scalable system accelerating early-stage drug target selection for immune-mediated disease.
Abstract
Benchmark brown dwarf companions with well-determined ages and model-independent masses are powerful tools to test substellar evolutionary models and probe the formation of giant planets and ...brown dwarfs. Here, we report the independent discovery of HIP 21152 B, the first imaged brown dwarf companion in the Hyades, and conduct a comprehensive orbital and atmospheric characterization of the system. HIP 21152 was targeted in an ongoing high-contrast imaging campaign of stars exhibiting proper-motion changes between Hipparcos and Gaia, and was also recently identified by Bonavita et al. (2022) and Kuzuhara et al. (2022). Our Keck/NIRC2 and SCExAO/CHARIS imaging of HIP 21152 revealed a comoving companion at a separation of 0.″37 (16 au). We perform a joint orbit fit of all available relative astrometry and radial velocities together with the Hipparcos-Gaia proper motions, yielding a dynamical mass of
24
−
4
+
6
M
Jup
, which is 1–2
σ
lower than evolutionary model predictions. Hybrid grids that include the evolution of cloud properties best reproduce the dynamical mass. We also identify a comoving wide-separation (1837″ or 7.9 × 10
4
au) early-L dwarf with an inferred mass near the hydrogen-burning limit. Finally, we analyze the spectra and photometry of HIP 21152 B using the Saumon & Marley (2008) atmospheric models and a suite of retrievals. The best-fit grid-based models have
f
sed
= 2, indicating the presence of clouds,
T
eff
= 1400 K, and
log
g
=
4.5
dex
. These results are consistent with the object’s spectral type of T0 ± 1. As the first benchmark brown dwarf companion in the Hyades, HIP 21152 B joins the small but growing number of substellar companions with well-determined ages and dynamical masses.
Defects of motile cilia cause primary ciliary dyskinesia (PCD), characterized by recurrent respiratory infections and male infertility. Using whole-exome resequencing and high-throughput mutation ...analysis, we identified recessive biallelic mutations in ZMYND10 in 14 families and mutations in the recently identified LRRC6 in 13 families. We show that ZMYND10 and LRRC6 interact and that certain ZMYND10 and LRRC6 mutations abrogate the interaction between the LRRC6 CS domain and the ZMYND10 C-terminal domain. Additionally, ZMYND10 and LRRC6 colocalize with the centriole markers SAS6 and PCM1. Mutations in ZMYND10 result in the absence of the axonemal protein components DNAH5 and DNALI1 from respiratory cilia. Animal models support the association between ZMYND10 and human PCD, given that zmynd10 knockdown in zebrafish caused ciliary paralysis leading to cystic kidneys and otolith defects and that knockdown in Xenopus interfered with ciliogenesis. Our findings suggest that a cytoplasmic protein complex containing ZMYND10 and LRRC6 is necessary for motile ciliary function.
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