brown dwarf Archives

Artist impression of exoplanet Gaia-4b -- ESA

Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Gaia Mission, Imaging & Spectroscopy, Press Release, Stellar Cartography

Wobbling Stars Reveal Hidden Companions In Gaia Data

by Keith CowingFebruary 4, 2025

New research, published today, uses data collected by ESA’s Gaia spacecraft to confirm the existence of two mysterious celestial objects. Gaia-4b is a ‘Super-Jupiter’ exoplanet, and Gaia-5b a brown dwarf. […]

Newly formed giant planet - Grok via Astrobiology.com

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

Formation of Giant Planets

by Keith CowingJanuary 24, 2025January 24, 2025

Giant planets dominate the mass of many planetary systems, including the Solar System, and represent the best-characterized class of extrasolar planets.

Radius versus mass for all transiting companions from 7 - 150 MJ . The black dashed lines depict the canonical 13 and 80 MJ BD boundaries. The solid purple line at 42 MJ shows the proposed Ma & Ge (2014) boundary between planet and star-like BDs. Note: systems where the primary object is a white dwarf or brown dwarf are not shown. -- astro-ph.EP

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

11 New Transiting Brown Dwarfs and Very Low Mass Stars from TESS

by Keith CowingJanuary 22, 2025January 22, 2025

We present the discovery of 11 new transiting brown dwarfs and low-mass M-dwarfs from NASA’s TESS mission: TOI-2844, TOI-3122, TOI-3577, TOI-3755, TOI-4462, TOI-4635, TOI-4737, TOI-4759, TOI-5240, TOI-5467, and TOI-5882.

Diagram of the MSG model algorithm for cloudy substellar atmospheres. The boxes with a dashed outline indicate parameters that are inputs to the model. The boxes with a dotted outline indicate control processes within the workflow. For a detailed explanation of the cloud formation process, see section 2. For a detailed explanation of the control process, see section 4.3. For the convergence criteria considered under the control process see section 4.1 -- astro-ph.EP

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

The MSG Model For Cloudy Substellar Atmospheres: A Grid Of Self-consistent Substellar Atmosphere Models With Microphysical Cloud Formation

by Keith CowingJanuary 22, 2025January 22, 2025

State-of-the-art JWST observations are unveiling unprecedented views into the atmospheres of substellar objects in the infrared, further highlighting the importance of clouds. Current forward models struggle to fit the silicate […]

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.

Top panel: Final flux-calibrated NIRSpec/Prism (blue) and MIRI/LRS (red) spectra of SIMP 0136+0933, compared to the spectrum presented in Vos et al. (2023) (black) and error (shaded in grey). For the NIRSpec and MIRI spectra, each spectrum is plotted individually. Notable absorption features are indicated by horizontal black lines and their labels. For each instrument, we plot each spectrum individually, so the observed spread is a result of both noise and intrinsic variability. Bottom panel: Minimum spectrum subtracted from the maximum spectrum. The maximum and minimum spectra were identified using the 4.5 − 5.1 µm light curve (Figure 4). -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report

The JWST Weather Report From the Isolated Exoplanet Analog SIMP 0136+0933: Pressure-Dependent Variability Driven by Multiple Mechanisms

by Keith CowingNovember 26, 2024November 26, 2024

Isolated planetary-mass objects share their mass range with planets but do not orbit a star. They lack the necessary mass to support fusion in their cores and thermally radiate their […]

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.

brown dwarf

Wobbling Stars Reveal Hidden Companions In Gaia Data

Formation of Giant Planets

11 New Transiting Brown Dwarfs and Very Low Mass Stars from TESS

The MSG Model For Cloudy Substellar Atmospheres: A Grid Of Self-consistent Substellar Atmosphere Models With Microphysical Cloud Formation

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

The JWST Weather Report From the Isolated Exoplanet Analog SIMP 0136+0933: Pressure-Dependent Variability Driven by Multiple Mechanisms

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

COSPAR Panel On Planetary Protection Endorses Proposed Update To The Mars Planetary Protection Policy

Jupiter Icy Moons Explorer Astrobiology Droid Completes Earth Flyby

Roman Space Telescope’s Wide Field Instrument Activated – Coronagraph Checked Out

Nonequilibrium Formation of C4 Carbonyls in Interstellar Ices Linked to Amino Acids

The North Pole Of Mars Is Less Dusty Than Scientists Thought