Close-in small planets and their distant giant companions. Masses and periods of exoplanets from our survey (bold squares) and the NASA Exoplanet Archive (faded circles) for context . Red/blue points indicate planets discovered using the transit/RV method. Red squares show true masses of transiting planets in the Distant Giants Survey measured by RVs (Polanski et al. 2024), while blue squares show minimum mass measurements (M sin i). For systems with multiple transiting planets, we show the parameters of the transiting planet with the lowest TOI designation that passed our filters. Red squares with yellow borders indicate systems in which we detected a linear/quadratic trend. Giant planets in our sample are connected to the inner planet in their system by a black line. The box corresponds to our nominal definition of a Distant Giant. -- astro-ph.EP

Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Exploration Gear & Tech, Gas Giants, Status Report, Stellar Cartography

The TESS-Keck Survey XXIV: Outer Giants May be More Prevalent in the Presence of Inner Small Planets

by Keith CowingJanuary 14, 2025January 14, 2025

We present the results of the Distant Giants Survey, a three-year radial velocity (RV) campaign to search for wide-separation giant planets orbiting Sun-like stars known to host an inner transiting […]

The spatial coverage of our study of L 1688A, with the underlying extinction map being computed using 2MASS catalog (Cutri et al. 2003) adopting the NICE technique from Lada et al. (1994). The color bar shows the extinction range. The red square encloses the area of the W band observations covering a field of 20′ × 20′ corresponding to a linear scale of 0.8 pc. -- astro-ph.SR

Astrochemistry, Astronomy & Telescopes, Biosignatures & Paleobiology, Brown Dwarfs, Exoplanets, -moons, -comets, Gaia Mission, Icy Worlds, Interstellar, Status Report, Water/Hycean Worlds & Oceanography

Water-Bearing Objects in the Core of the Rho Ophiuchi Cloud Complex

by Keith CowingJanuary 3, 2025January 3, 2025

We present a study of very low-mass stars and brown dwarfs in the rich star-forming core of the Rho Ophiuchi cloud complex. The selection of the sample relies on detecting […]

Light curves of the microlensing event OGLE-2015-BLG-1609 with three microlensing model topologies for positive values of the impact parameter u0. The difference between the topologies is visible only during the planetary anomaly (HJD ∼ 2457270; see Fig. 2). The photometry comes from the OGLE, MOA, RoboNet, and MiNDSTEp projects. -- astro-ph.EP

Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

OGLE-2015-BLG-1609Lb: Sub-jovian Planet Orbiting A Low-mass Stellar Or Brown Dwarf Host

by Keith CowingDecember 18, 2024December 18, 2024

We present a comprehensive analysis of a planetary microlensing event OGLE-2015-BLG-1609. The planetary anomaly was detected by two survey telescopes, OGLE and MOA.

Infrared image of the center of the Orion Nebula taken with the NIRCam instrument on NASA's James Webb Space Telescope. The insets show expanded images of two faint proplyds from the Hubble Space Telescope at optical wavelengths and Webb at infrared wavelengths. For each proplyd, a small protoplanetary disk is detected in silhouette in the optical image, which is surrounded by a bright ionization front that is produced by the intense UV radiation from the most massive stars. The brown dwarf at the center of each disk is detected in the infrared image from Webb. Spectroscopy from the NIRSpec instrument on Webb has confirmed that these objects are brown dwarfs based on their cool temperatures. -- NASA/ESA/CSA, Mark McCaughrean/ESA, Massimo Robberto/STScI/JHU, Kevin Luhman/Penn State, Catarina Alves de Oliveira/ESA

Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Press Release

Webb And Hubble Discover Brown Dwarf Protoplanetary Disks In The Orion Nebula

by Keith CowingNovember 25, 2024November 25, 2024

Newborn stars are surrounded by disks of gas and dust within which planets are born, known as protoplanetary disks. In the Orion Nebula, the brightest and most massive stars emit […]

The top panel shows the synthetic spectrum for a Y dwarf at 10 pc with the atmospheric parameters given in the legend. WISE and JWST filter bandpasses are illustrated as red and yellow lines respectively. The middle and lower panels show the ratio of this spectrum divided by a spectrum where the surface gravity has been reduced, and by a spectrum where the metallicity is reduced, respectively. The total energy emitted by the lower gravity dwarf is greater because the radius is larger (Marley et al. 2021), hence the average value in the middle panel is < 1. Note that all three models have similar flux levels averaged over the λ ≈ 4.5 µm flux peak, for example through an imaging filter, although the strength of the absorption features at these wavelengths (primarily due to CO and CO2) are sensitive to gravity. See Section 3 for further discussion. -- astro-ph.SR

Astronomy & Telescopes, Atmospheres, Climate, Weather, Brown Dwarfs, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Redshifting the Study of Cold Brown Dwarfs and Exoplanets: the Mid-Infrared Wavelength Region as an Indicator of Surface Gravity and Mass

by Keith CowingNovember 18, 2024November 18, 2024

JWST is opening many avenues for exploration. For cold brown dwarfs and exoplanets, JWST has opened the door to the mid-infrared wavelength region, where such objects emit significant energy.

Selection of the astrometric solutions for our mock astrometric binary catalog. This figure in inspired by Figure 3 of Halbwachs et al. (2023), who present the same quantities for the astrometric solutions of real sources published in Gaia DR3. Upper left panel shows all solutions with a0/σa0 > 5 and F2 < 25. The cloud of points at long Porb and low fm, ast consists mostly of good solutions, while the vertical stripes of solutions with high fm, ast and short periods are all spurious. In the upper right, green and gray show the distributions of solutions with fm, ast < 0.3 M⊙ (presumed mostly reliable) and fm, astt > 0.3 M⊙ (presumed mostly spurious). Black line shows the empirical cut (Equation 20) below which solutions are discarded. Bottom panels show only solutions that pass this cut. Red lines in these panels show additional cuts applied to the final solutions: only solutions below (left panel) and above (right panel) the red lines were retained. -- astro-ph.GA

Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Status Report, Stellar Cartography

A Generative Model for Gaia Astrometric Orbit Catalogs: Selection Functions for Binary Stars, Giant Planets, and Compact Object Companions

by Keith CowingNovember 7, 2024November 7, 2024

Astrometry from Gaia DR3 has produced a sample of ∼170,000 Keplerian orbital solutions, with many more anticipated in the next few years. These data have enormous potential to constrain the […]

An international team of astronomers has used the NASA/ESA/CSA James Webb Space Telescope to detect the first brown dwarf candidates outside the Milky Way in the star cluster NGC 602. larger image - ESA/NASA

Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Press Release

The First Young Brown Dwarfs Found Outside Our Home Galaxy?

by Keith CowingOctober 23, 2024October 23, 2024

Picture the outskirts of the Small Magellanic Cloud, a satellite galaxy of our Milky Way, roughly 200 000 light-years from Earth: here lies the young star cluster NGC 602. The […]

The MIRI/MRS (this work), NIRspec/PRISM and NIRSpec/G395M Luhman et al. (2024) spectrum of WISE 0855 from 0.8 to 22 µm. Panel a) shows the NIRspec/PRISM data in red and panel from 0.8 to 2.2µm b) the NIRspec/G395M in green and MIRI/MRS data in blue from 2.2 to 22 µm. Insets c) and d) show the overlap between the three data sets from 3.5 to 5.4 µm and the ammonia feature from 8.0 to 13.0 µm, respectively. The most dominant absorbing species are presented above the spectrum in various colors. For better visualization he data was binned to a resolution of R = 1000 for MIRI/MRS and NIRSpec/G395M and R = 100 for NIRSpec/PRISM. -- astro-ph.EP

Astrochemistry, Atmospheres, Climate, Weather, Brown Dwarfs, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Water Depletion and 15NH3 in the Atmosphere of the Coldest Brown Dwarf Observed With JWST/MIRI

by Keith CowingOctober 17, 2024October 17, 2024

With a temperature of ∼285 K WISE0855 is the coldest brown dwarf observed so far. Using the James Webb Space Telescope (JWST) we obtained observations that allow us to characterize […]

Top: The high-resolution spectrum of the T-dwarf Gl229 B analyzed using ExoJAX2 (Kawashima et al. submitted) with ∼ 108 total molecular absorption lines considered. The blue solid line shows the median value, while the blue shaded regions indicate the 95% credible interval. Black points represent the observed Subaru/IRD data. The periodic increases in the residuals observed correspond to the gaps between orders. Bottom: Medium-resolution transmission spectrum of WASP-39 b analyzed using ExoJAX2 and the HMC-NUTS method. The black solid line represents the model derived from the median values of each parameter obtained through MCMC sampling, with the 95% credible interval shaded in gray. The blue points show the observed planetary radii from JWST NIRSpec/G395H observations. The vertical axis on the left shows the planetary radius, while the vertical axis on the right displays the corresponding pressure. The contributions of CO, CO2, H2O, SO2, gray clouds, and collision-induced absorption (CIA) are represented by colored shading with an offset of -0.01 Rs. -- astro-ph.SR

AI - Data - Apps - Cybernetics, Apps - Games, Astronomy & Telescopes, Brown Dwarfs, Imaging & Spectroscopy, Status Report, Stellar Cartography

Differentiable Modeling of Planet and Substellar Atmosphere: High-Resolution Emission, Transmission, and Reflection Spectroscopy with ExoJAX2

by Keith CowingOctober 10, 2024October 10, 2024

Modeling based on differentiable programming holds great promise for astronomy, as it can employ techniques such as Hamiltonian Monte Carlo, gradient-based optimization, and other machine learning techniques.

This artist’s concept shows a brown dwarf, an object that is at least 13 times the mass of Jupiter but not massive enough to begin nuclear fusion in its core, which is the defining characteristic of a star. Scientist using NASA’s Spitzer Space Telescope recently made the first ever direct measurement of wind on a brown dwarf. Credits: NASA/JPL-Caltech

Astronomy & Telescopes, Atmospheres, Climate, Weather, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Status Report

Physical Parameters and Properties of 20 Cold Brown Dwarfs in JWST

by Keith CowingOctober 6, 2024October 6, 2024

We present a comprehensive analysis of 20 T and Y dwarfs using spectroscopy from the NIRSpec CLEAR/PRISM and MIRI LRS instruments on the James Webb Space Telescope. To characterize the […]

Brown Dwarfs

The TESS-Keck Survey XXIV: Outer Giants May be More Prevalent in the Presence of Inner Small Planets

Water-Bearing Objects in the Core of the Rho Ophiuchi Cloud Complex

OGLE-2015-BLG-1609Lb: Sub-jovian Planet Orbiting A Low-mass Stellar Or Brown Dwarf Host

Webb And Hubble Discover Brown Dwarf Protoplanetary Disks In The Orion Nebula

Redshifting the Study of Cold Brown Dwarfs and Exoplanets: the Mid-Infrared Wavelength Region as an Indicator of Surface Gravity and Mass

A Generative Model for Gaia Astrometric Orbit Catalogs: Selection Functions for Binary Stars, Giant Planets, and Compact Object Companions

The First Young Brown Dwarfs Found Outside Our Home Galaxy?

Water Depletion and 15NH3 in the Atmosphere of the Coldest Brown Dwarf Observed With JWST/MIRI

Differentiable Modeling of Planet and Substellar Atmosphere: High-Resolution Emission, Transmission, and Reflection Spectroscopy with ExoJAX2

Physical Parameters and Properties of 20 Cold Brown Dwarfs in JWST

Opportunity to Contribute to NASA DARES Community White Paper on Phototrophic Biosignatures

NASA Establishes Mars Forward Operational Risk and Contamination Evaluation (M-FORCE) Tiger Team to Shape Mars Planetary Protection Protocols

Miraflores Butte On Mars

Ocean World Exploration: 2026 American Samoa ROV + Mapping Exploration

Development Of An Adaptive Optics Testbed At MPIA For The ELT/Planetary Camera And Spectrograph (PCS)

Hayabusa Symposium 2026

HWO2026 (Habitable Worlds Observatory)

2nd European Interstellar Symposium

American Society for Gravitational and Space Research (ASGSR) 2026

Life And Space 2026