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Red dwarf

A red dwarf is a small, low-mass main-sequence star of spectral type M, defined by strong titanium oxide absorption bands in its optical spectrum and characterized by cool surface temperatures that give it a reddish appearance. These stars have masses ranging from 0.08 to 0.6 times that of the Sun and surface temperatures between approximately 2,400 and 3,700 K.^[1]^[2] Red dwarfs constitute the most common class of stars in the Milky Way galaxy, accounting for roughly 70–75% of all stars.^[1]^[2] Their low masses result in slow hydrogen fusion rates, enabling main-sequence lifetimes that can exceed 10 trillion years for the lowest-mass examples—vastly longer than the universe's current age of about 13.8 billion years.^[2] These stars are inherently faint, with luminosities a fraction of the Sun's, making them invisible to the naked eye and requiring telescopes for observation; notable examples include Proxima Centauri, the closest known star to the Sun at 4.24 light-years away.^[2] Due to their prevalence and stability, red dwarfs play a key role in galactic stellar populations and are prime targets for exoplanet searches, as their close-in habitable zones allow for easier detection of potentially Earth-like worlds.^[2] Many exhibit magnetic activity, including flares that can impact planetary atmospheres, though their long lifespans provide extended windows for planetary system evolution.^[1]

Definition and Classification

Definition

Red dwarfs are a class of low-mass main-sequence stars classified under spectral type M, spanning subtypes from M0 to M9, with masses typically ranging from about 0.08 to 0.6 solar masses (M⊙).^[3]^[4] These stars represent the most common type of hydrogen-fusing stellar object in the galaxy, forming the lower end of the main sequence on the Hertzsprung-Russell diagram.^[5] They are distinguished from higher-mass main-sequence stars, such as G- and K-type dwarfs, by their significantly lower masses and luminosities, as well as from substellar objects like brown dwarfs, which fall below the hydrogen-burning minimum mass of approximately 0.075–0.08 M⊙ and thus cannot sustain core fusion of hydrogen into helium.^[6] This mass threshold marks the boundary between true stars and failed stars, with red dwarfs maintaining stable fusion over extraordinarily long timescales.^[5] Red dwarfs constitute about 75% of all stars in the Milky Way and are presumed to dominate the stellar population across the universe due to their prevalence in star formation processes.^[2] The term "red dwarf" derives from their relatively cool surface temperatures, which result in peak emission in the red and infrared portions of the spectrum, giving them a reddish or orange appearance to observers.^[7]

Spectral Classification

Red dwarfs are classified within the Morgan-Keenan (MK) system using spectral types ranging from M0V to M9V, where the "M" denotes the coolest stellar class and the "V" indicates main-sequence luminosity. These subtypes reflect decreasing effective temperatures from approximately 3900 K at M0V to 2300 K at M9V, with finer subdivisions (e.g., M0.5V, M5.5V) based on the relative strengths of absorption features in optical and near-infrared spectra. The primary diagnostic features for M subtypes include molecular bands of titanium monoxide (TiO), particularly the prominent ε-band at 7055 Å and γ-band at 6651 Å, which strengthen from early to mid-M types before weakening in the latest subtypes; vanadium oxide (VO) bands near 7900–8600 Å, more evident in giants but present in dwarfs; and atomic lines such as neutral sodium (Na I) at 8183/8195 Å, which broaden and deepen toward later types, along with neutral calcium (Ca I) at 4226 Å and the calcium hydride (CaH) band at 6971 Å. Early M types (M0V–M2V) are distinguished by dominant TiO absorption with minimal alkali interference, while mid-to-late types (M3V–M9V) show enhanced Na I resonance lines and CaH, providing a continuous sequence for precise typing.^[8]^[9] Spectral standards anchor this system, with well-established examples including Gliese 581 for M3V, featuring moderate TiO strength and emerging Na I lines; Proxima Centauri (Gliese 551) for M5.5Ve, marked by strong TiO bands, CaH absorption, and chromospheric emission in Ca II; and LP 944-20 for M9V, showing diminished TiO and prominent alkali doublets. These standards, derived from high-resolution spectra, enable comparison-based classification. Subtypes further distinguish luminosity and metallicity: the "V" class applies to typical solar-neighborhood dwarfs, while "VI" denotes subdwarfs (sdM), which exhibit weaker TiO and CaH bands due to lower metallicity ([Fe/H] ≈ -0.5 to -1.0) and are fainter by 1–2 magnitudes in absolute terms; extreme subdwarfs (esdM) extend this to [Fe/H] < -1.5. Ultracool dwarfs occupy M8V–M9V, transitioning to L types around 2300–2200 K, where TiO bands fade significantly, metal hydride features like chromium hydride (CrH) at 8611 Å emerge, and broad Na I and potassium (K I) lines dominate, marking the onset of brown dwarf-like spectra.^[10]^[11] Recent refinements incorporate near-infrared spectra and astrometry from missions like Gaia, whose Data Release 3 (2022) provides low-resolution spectra for over 10 million sources, enabling precise subtyping of nearby M dwarfs through parallax-confirmed distances and feature ratios (e.g., TiO vs. H2O bands), improving accuracy for ultracool transitions by cross-matching with 2MASS and SDSS data.^[12]

Physical Characteristics

Size, Mass, and Composition

Red dwarfs, or M-type main-sequence stars, possess masses ranging from approximately 0.08 to 0.6 solar masses (M⊙), corresponding to radii between about 0.1 and 0.6 solar radii (R⊙).^[1] This compact size results in average densities 10 to 100 times that of the Sun, with central densities typically on the order of 100 to 400 g/cm³ in the lowest-mass examples.^[13] The mass-radius relation for these low-mass stars follows an approximation of R \propto M^{0.8}, reflecting how gravitational compression balances internal pressures more efficiently at lower masses compared to higher-mass stars.^[14] The structural stability of red dwarfs arises partly from partial electron degeneracy pressure in their dense cores, which supplements thermal pressure to counteract gravity, particularly in stars below 0.2 M⊙ where degeneracy effects become significant.^[13] Stellar evolution models incorporate detailed equations of state to accurately predict these density profiles, accounting for interactions between ions, electrons, and radiation in the high-density regime.^[13] Compositionally, red dwarfs consist primarily of about 74% hydrogen, 24% helium, and 2% heavier elements (metals) by mass, similar to the cosmic average for Population I stars.^[15] Variations in metallicity influence internal opacity, which in turn affects convective efficiency; lower-metallicity red dwarfs exhibit reduced opacity, potentially leading to shallower convection zones and altered energy transport.^[16] In terms of internal structure, red dwarfs with masses below approximately 0.35 M⊙ are fully convective, lacking a radiative core and mixing material throughout their interiors via turbulent motions.^[17] Higher-mass red dwarfs (0.35–0.6 M⊙) feature thin radiative zones near the center surrounded by extensive convective envelopes, a configuration that influences their overall thermal profiles and long-term evolution.^[17]

Temperature, Luminosity, and Spectra

Red dwarfs exhibit effective temperatures ranging from approximately 3,900 K for early M subtypes like M0 to about 2,300 K for late subtypes such as M9, with temperatures generally decreasing as spectral types progress from M0 to M9.^[18] This cool temperature regime results in low radiative output, with luminosities spanning roughly 0.0001 to 0.08 times that of the Sun, depending on mass and evolutionary stage.^[19] The luminosity closely follows the mass-luminosity relation approximated as L \propto M^{3.5} along the Hayashi track for fully convective low-mass stars.^[19] Due to their infrared-dominated emission, deriving bolometric luminosities for red dwarfs requires significant corrections to visual-band photometry, as much of their energy output peaks in the near-infrared rather than optical wavelengths.^[20] Their reddish appearance stems from this thermal profile, characterized by B-V color indices exceeding 1.5, which distinguishes them from hotter main-sequence stars.^[21] The spectra of red dwarfs approximate blackbody curves but deviate markedly due to strong molecular absorption features, particularly titanium oxide (TiO) and vanadium oxide (VO) bands in the optical and water vapor (H₂O) and carbon monoxide (CO) bands in the near-infrared.^[22] These absorptions, prominent in the 2.3–2.4 μm region for CO overtone bands and overlapping H₂O features, complicate spectral analysis but provide key diagnostics for atmospheric composition and temperature.^[22] The inherent faintness of red dwarfs poses significant observational challenges, as their low luminosities make ground-based detection difficult, especially for late subtypes; space telescopes like Gaia DR3 enable precise photometry and luminosity function studies through astrometric and low-resolution spectroscopic data for millions of cool dwarfs.^[23] Similarly, the James Webb Space Telescope (JWST) excels in infrared observations, resolving faint red dwarf spectra and enabling detailed characterization of their thermal properties in crowded fields or distant systems.^[12]

Magnetic Activity and Flares

Red dwarf stars exhibit exceptionally strong magnetic fields, generated through dynamo action within their fully convective interiors, where turbulent motions amplify and sustain magnetism throughout the stellar volume. These fields can reach strengths of up to several kilogauss (kG), as observed in early-M dwarfs via spectropolarimetry, with global dipolar components often exceeding 1 kG in active examples. The dynamo efficiency is closely tied to rotation, with faster-rotating red dwarfs producing stronger fields and higher activity levels, following a well-established rotation-activity relation where X-ray luminosity scales with the square of the Rossby number until saturation.^[24] These intense magnetic fields drive frequent stellar flares, sudden releases of energy that can amplify the star's luminosity by factors of 10^3 to 10^5 above quiescent levels, lasting from minutes to hours. Such superflares arise from magnetic reconnection in the corona, converting stored magnetic energy—typically on the order of 10^{30} to 10^{34} erg—into high-energy radiation across X-ray, ultraviolet, and optical wavelengths.^[25] Recent observations have highlighted the potency of these events. In 2025, the James Webb Space Telescope (JWST) captured ultraviolet light curves from a red dwarf, revealing flares that emit bright far-UV radiation far exceeding prior estimates, with peaks indicating extreme coronal heating.^[26] Complementing this, Chandra X-ray Observatory data from the same year on the nearby red dwarf Wolf 359 detected 18 X-ray flares over just 3.5 days, underscoring the potential for intense space weather that could bombard orbiting planets with particle radiation and erode atmospheres.^[27]^[28] Magnetic activity in red dwarfs evolves with age and rotation, declining significantly over the first 1 to 2 billion years as spin-down via magnetic braking reduces dynamo vigor, transitioning stars from rapid rotators with saturated activity to slower, less active ones. This decline manifests in reduced flare rates and X-ray emissions, as quantified in age-rotation-activity relations derived from photometric and spectroscopic surveys.^[29] Additionally, magnetic spots cover substantial portions of the photosphere, inducing photometric variability of 10-20% in active young red dwarfs, which diminishes as activity wanes.^[30] Such flares pose risks to planetary habitability by delivering sterilizing radiation doses, though protective magnetic fields on worlds like those around Proxima Centauri might mitigate some effects.^[28]

Formation and Evolution

Stellar Formation

Red dwarfs, the most abundant stellar type in the Milky Way, primarily form through the gravitational collapse of dense fragments within molecular clouds, particularly in clustered environments. These low-mass stars (0.08–0.6 M⊙) occupy the low-mass end of the initial mass function (IMF), which describes the distribution of stellar masses at birth. The Salpeter IMF, characterized by a power-law slope of α ≈ 2.35, favors the formation of low-mass stars over massive ones, resulting in a higher number of red dwarfs relative to higher-mass counterparts. This distribution arises from the turbulent fragmentation of protostellar cores in giant molecular clouds, where Jeans instability leads to the collapse of gas clumps into multiple low-mass protostars.^[31] Additionally, fragmentation of circumstellar disks around higher-mass protostars contributes to the production of low-mass companions, including red dwarfs, enhancing multiplicity in young clusters.^[31] During the protostellar phase, these objects undergo gravitational contraction along the Hayashi track on the Hertzsprung-Russell diagram, a nearly vertical path where luminosity decreases as the effective temperature stabilizes around 3,000–4,000 K due to the opacity of their fully convective envelopes. This phase lasts approximately 10–50 million years for stars of 0.1–0.5 M⊙, as the contraction timescale scales inversely with mass, allowing low-mass cores to efficiently collapse and reach the zero-age main sequence via Kelvin-Helmholtz contraction powered by gravitational energy release.^[32] The efficiency of low-mass core collapse is high in these environments, with simulations indicating that over 70% of fragments in turbulent clouds form bound objects below 0.5 M⊙, owing to the shallow potential wells and reduced radiative feedback compared to massive star formation. Red dwarf formation is more prevalent in dense interstellar regions, such as the cores of molecular clouds with volumes exceeding 10^4 solar masses, where higher gas densities (n > 10^4 cm^{-3}) promote rapid collapse and clustering.^[33] Binary and multiple systems are common, with roughly 50% of red dwarfs having companions, often formed through disk fragmentation or capture in crowded clusters, influencing their dynamical evolution.^[34] Recent observations using the Keck and Subaru telescopes in 2025 revealed a brown dwarf companion orbiting the mid-M dwarf LSPM J1446+4633 at ~4.3 AU, challenging traditional disk fragmentation models by suggesting enhanced mechanisms for substellar companions around low-mass primaries and necessitating revisions to low-mass star formation theories.^[35]

Lifespan and Evolutionary Stages

Red dwarfs, with masses between approximately 0.08 and 0.6 solar masses (M⊙), exhibit extraordinarily long main-sequence lifetimes due to their low core temperatures and efficient hydrogen fusion via the proton-proton (pp) chain. The fusion rate in these stars scales proportionally to density (ρ) and temperature (T) as ρ T^{4/3} ν, where ν is a temperature-dependent factor, but their central temperatures range only from about 3 to 15 million Kelvin (MK), resulting in fusion rates thousands to millions of times slower than in more massive stars. Consequently, red dwarfs with masses of 0.1 to 0.5 M⊙ are projected to remain on the main sequence for trillions of years at the low end to tens of billions of years at the high end of this range (for example, ~6–12 trillion years for 0.1 M⊙ and ~50 Gyr for 0.5 M⊙), far exceeding the current age of the universe at roughly 13.8 Gyr.^[2] Throughout their main-sequence phase, red dwarfs evolve gradually, cooling and contracting over time as they fuse hydrogen into helium in their cores, without undergoing rapid structural changes like those in higher-mass stars. Unlike stars above about 0.5 M⊙, red dwarfs lack sufficient core mass to ignite helium fusion explosively in a helium flash; instead, their evolution proceeds slowly until the core becomes dominated by helium after trillions of years. For the lowest-mass red dwarfs (around 0.08 M⊙), this phase could last up to 10^{12} years or more, after which they are expected to transition directly into helium white dwarfs with final masses of 0.2 to 0.5 M⊙, shedding negligible outer layers in the process. Observationally, all known red dwarfs are relatively young, with ages less than 10 Gyr, as the universe has not yet aged enough to reveal examples in advanced evolutionary stages. Theoretical models suggest that in the distant future, as more massive stars exhaust their fuel and evolve off the main sequence, red dwarfs will dominate the stellar population, gradually fading into dim, cool remnants. Recent simulations using the Modules for Experiments in Stellar Astrophysics (MESA) code from the 2020s have refined predictions of these end-stage helium-burning phases, confirming the absence of significant outbursts and emphasizing the stability of low-mass stellar evolution.

Planetary Systems

Planet Formation Mechanisms

Planet formation around red dwarfs primarily occurs within protoplanetary disks, which are circumstellar disks of gas and dust that form as byproducts of the star's own formation process. These disks around low-mass M-type stars are notably smaller in radial extent and shorter-lived compared to those around more massive stars, typically persisting for only 1-10 million years due to the lower gravitational influence and weaker irradiation from the central star. This brevity limits the timescale available for planet assembly, favoring mechanisms that operate on rapid scales, such as dust settling toward the midplane and pebble accretion, where centimeter- to meter-sized particles efficiently aggregate into larger bodies. Observations and simulations indicate that the low disk masses—often a few percent of the stellar mass—promote inward radial drift of solids, concentrating materials in compact inner regions suitable for terrestrial planet formation.^[36]^[37]^[38] The dominant theoretical frameworks for planet formation in these environments are core accretion and gravitational instability, each with distinct applicability to red dwarf systems. Core accretion begins with the buildup of solid cores from planetesimals in the inner disk, potentially accreting gas envelopes to form gas giants if the core reaches a critical mass of about 10 Earth masses before disk dispersal; however, around red dwarfs, this process preferentially yields rocky super-Earths and mini-Neptunes due to the cooler temperatures and lower disk masses that hinder efficient gas capture. Gravitational instability, in contrast, involves the fragmentation of massive, gravitationally unstable outer disk regions into clumps that collapse directly into giant planets or brown dwarfs, a mechanism that may be more viable around red dwarfs where core accretion struggles to produce Jupiters within the short disk lifetimes. Challenges arise from the rapid photoevaporation and viscous evolution of these disks, which can disperse material before full planet formation, particularly for gas giants, though hybrid scenarios combining both mechanisms have been proposed to explain observed wide-orbit companions.^[39]^[40]^[41] The metallicity of the host red dwarf plays a crucial role in modulating planet formation efficiency, with higher metal content enhancing the availability of solid building blocks for core accretion. Studies of M dwarf samples reveal a strong planet-metallicity correlation for giant planets, where metal-rich hosts ([Fe/H] > 0) are 4-5 times more likely to harbor such worlds, as increased dust opacity and planetesimal formation rates boost core growth rates. This dependence is particularly pronounced in radial velocity surveys, which may introduce biases toward detecting massive planets around brighter, metal-rich targets, though transit surveys confirm the trend for smaller rocky planets as well. Low-metallicity red dwarfs, common in the galactic halo, thus tend to form fewer and smaller planets overall.^[42]^[43]^[44] Recent discoveries in 2025 have highlighted hybrid formation modes involving brown dwarf companions, suggesting they influence planet yields around red dwarfs by altering disk dynamics. For instance, the identification of a ~60 Jupiter-mass brown dwarf orbiting a red dwarf at 4.3 AU via direct imaging implies that such companions can form through disk fragmentation and subsequently shepherd or disrupt inner planet formation, potentially reducing the number of close-in worlds while enabling wider-orbit giants. These findings, drawn from Subaru and Keck Observatory observations, indicate that brown dwarf interactions may bridge core accretion and instability pathways, providing new constraints on models of multi-object system evolution in low-mass stellar environments.^[45]^[46]^[47]

Known Exoplanets and Systems

Red dwarfs, or M-type stars, host a substantial fraction of the known exoplanets, with approximately 25% of the over 6,000 confirmed exoplanets as of October 2025 orbiting these cool, low-mass stars, despite historical survey biases favoring brighter, more massive hosts.^[48]^[49] The detection of these planets is dominated by the transit method, which identifies dips in stellar brightness as planets pass in front of their host, and radial velocity measurements, which detect the star's wobble due to gravitational pulls; missions like NASA's Transiting Exoplanet Survey Satellite (TESS) and the James Webb Space Telescope (JWST) have excelled in transits around faint M dwarfs, while ground-based spectrographs such as ESPRESSO on the Very Large Telescope have provided precise radial velocity confirmations.^[48]^[50] Around 25% of all confirmed exoplanets are found orbiting M dwarfs, reflecting their prevalence and the efficacy of these methods for detecting small, close-in worlds.^[48] Notable multi-planet systems around red dwarfs showcase diverse architectures, with the TRAPPIST-1 system standing out as a benchmark: this ultracool M8 dwarf, located 40 light-years away, hosts seven Earth-sized rocky planets in tight orbits ranging from 1.5 to 12 days, discovered via ground-based transits in 2017 and later refined with Spitzer and JWST observations.^[49] Proxima Centauri b, orbiting the closest star to the Sun at 4.2 light-years, is a 1.3 Earth-mass planet in the habitable zone with a 11.2-day period, detected by radial velocity in 2016 using instruments like HARPS. Recent 2025 discoveries highlight ongoing progress, including GJ 251 c, a super-Earth with a minimum mass of 3.88 Earths orbiting an M3 dwarf every 53.6 days in the habitable zone, confirmed via radial velocity with ESPRESSO and HARPS data from a star just 18 light-years distant.^[51]^[52] In the L 98-59 system, a new fifth planet, L 98-59 f, was confirmed in 2025 as a super-Earth with a minimum mass of 2.8 Earths on a 23-day orbit within the habitable zone of its M3V host, building on prior TESS transits of inner worlds and radial velocity follow-up.^[53]^[54] Another 2025 addition, TOI-6894 b, is a sub-Saturn gas giant (0.168 Jupiter masses, 0.855 Jupiter radii) with a 3.4-day orbit around an ultra-low-mass 0.2 solar mass red dwarf 238 light-years away, detected by TESS transits and representing the smallest host for such a giant planet.^[55]^[56] Planetary architectures around red dwarfs typically feature close-in orbits, with most planets having periods under 100 days due to the stars' low luminosity and compact habitable zones, often resulting in tidally locked configurations.^[36] Rocky planets are particularly frequent, with an average of 2-3 such worlds per M dwarf, far higher than around solar-type stars, as evidenced by TESS surveys revealing compact, multi-planet systems dominated by super-Earths and mini-Neptunes in resonant chains.^[57]^[58] Binary red dwarf companions, present in about 20% of systems, can influence planet formation and stability by truncating protoplanetary disks, yet many confirmed exoplanets thrive in these environments without dynamical disruption.^[57] These patterns underscore the efficiency of planet formation around low-mass stars, with high rocky planet yields driven by inward migration in metal-poor disks.^[36]

Habitability and Challenges

The habitable zone (HZ) around red dwarf stars, also known as M dwarfs, is exceptionally narrow and positioned close to the host star, typically spanning 0.01 to 0.1 AU, owing to the stars' low luminosity and cool temperatures.^[59] This proximity increases the likelihood of tidal locking for orbiting planets, resulting in synchronous rotation where one hemisphere remains in perpetual daylight and the other in endless night.^[60] Such configurations can promote atmospheric loss, particularly through photolysis of water vapor and subsequent hydrogen escape to space, potentially depleting several Earth-ocean equivalents over time.^[61] A primary challenge to habitability arises from the intense stellar flares and associated ultraviolet (UV) and X-ray radiation, which can erode planetary atmospheres via photoionization and sputtering.^[62] Observations from NASA's Chandra X-ray Observatory in 2025, focusing on red dwarfs like Wolf 359, reveal that combined steady and flaring emissions subject close-in planets to extreme space weather, capable of stripping atmospheres from Earth-sized worlds within tens of millions of years.^[62] Additionally, the prolonged early phase of heightened stellar activity in young red dwarfs—lasting up to a billion years—may drive runaway greenhouse states, sterilizing surfaces by boiling off oceans and preventing the emergence of life.^[61] Despite these obstacles, prospects for habitability persist in subsurface environments, where liquid water oceans beneath ice layers could shield against radiation, akin to Jupiter's moon Europa.^[63] Subglacial melting driven by geothermal heat may sustain such oceans even beyond the traditional HZ, expanding potential habitable niches around M dwarfs.^[63] The James Webb Space Telescope (JWST) enhances detection capabilities by observing infrared biosignatures, such as methane or dimethyl sulfide, in the atmospheres of HZ exoplanets orbiting red dwarfs.^[64] Moreover, 2025 modeling studies suggest that superflares contribute only modestly to atmospheric erosion—less than a factor of two increase in mass loss—indicating that planets with initial thick envelopes may retain volatiles longer than previously feared.^[65] Tidal effects from synchronous rotation often induce extreme climates, with scorching daysides and frozen nightsides, exacerbating energy imbalances.^[66] However, thick atmospheres, potentially dominated by CO₂ or H₂, can mitigate these disparities through efficient heat redistribution via winds and convection, fostering more uniform global temperatures.^[66] Systems like TRAPPIST-1, with multiple rocky planets in the HZ, exemplify how these dynamics interplay to influence overall viability.^[64]

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First steps of planet formation around very low mass stars and brown ...
Nov 2, 2022 · The very first step of planet formation includes the growth from micron-sized particles from the interstellar medium to pebbles. One of the main ...
[40]
Forming Gas Giants around a Range of Protostellar M-dwarfs by ...
Recent discoveries of gas giant exoplanets around M-dwarfs from transiting and radial velocity surveys are difficult to explain with core-accretion models.
[41]
Planet formation around M dwarfs via disc instability
M dwarf discs are most likely to fragment at distances 50− 60 AU from the host star. The error bars correspond to the Poisson (statistical) error. Only 20 ...
[42]
Rapid Formation of Super-Earths around M Dwarf Stars - Inspire HEP
Core-accretion model predicts few Jovian-mass planets orbiting red dwarfs ... Forming of giant planets by fragmentation of protoplanetary disks · Lucio ...<|separator|>
[43]
Metallicity Dependence of Giant Planets around M Dwarfs
Jan 16, 2025 · We find that (1) giant planets favor metal-rich M dwarfs at a 4σ–5σ confidence level, depending on the band of spectra used to derive metallicity.
[44]
Metallicity Dependence of Giant Planets around M Dwarfs - arXiv
Dec 11, 2024 · We investigate the stellar metallicity ([Fe/H] and [M/H]) dependence of giant planets around M dwarfs by comparing the metallicity distribution ...
[45]
Metallicity of M dwarfs - Astronomy & Astrophysics
The aim of this work is the study of the planet-metallicity and the planet-stellar mass correlations for M dwarfs from the ... ficient process of planet-formation ...
[46]
https://subarutelescope.org/en/results/2025/10/20/3609.html
[47]
Discovery of a Brown Dwarf Orbiting a Red Dwarf through the ...
... brown dwarf companion. This discovery provides a critical benchmark for testing brown dwarf formation scenarios and atmospheric models.
[48]
Discovery of Brown Dwarf Companion Provides New Insight into ...
Oct 20, 2025 · Keck Observatory and Subaru Telescope on Maunakea, Hawaiʻi Island, have discovered a brown dwarf companion orbiting a nearby red dwarf star, ...
[49]
NASA Exoplanet Archive
Other ; 6,042. Confirmed Planets. 10/30/2025 ; 708. TESS Confirmed Planets. 10/30/2025 ; 7,710. TESS Project Candidates. 10/26/2025 ; View more Planet and Candidate ...Planet Counts · Data · 2025 Exoplanet Archive News · Kepler Mission Information
[50]
Exoplanets - NASA Science
planets outside our solar system — confirmed by NASA has reached 6,000. The first exoplanet ...NASA's Kepler Discovers First... · Exoplanet Stories · The Search for Another Earth
[51]
TESS & ESPRESSO Discover Super-Earth & Mini-Neptune
The most widely used method to measure exoplanet masses is RV, which relies on detecting the Doppler shift induced by the gravitational tug of an orbiting ...
[52]
Demographics of M Dwarf Binary Exoplanet Hosts Discovered by ...
Jan 16, 2025 · Thus far more than 120 confirmed exoplanets have been detected around M dwarfs using TESS, 15 enabling improved constraints on exoplanet ...
[53]
NIRPS and TESS reveal a peculiar system around the M dwarf TOI ...
Oct 1, 2025 · Methods. We analyzed TESS and ground-based photometry, high-resolution imaging, and high-precision radial velocities (RVs) from NIRPS and HARPS ...
[54]
GJ 251 c - NASA Science
Oct 31, 2025 · GJ 251 c is a super Earth exoplanet that orbits a M-type star. Its mass is 3.88 Earths, it takes 53.6 days to complete one orbit of its star, ...
[55]
Discovery of a Nearby Habitable Zone Super-Earth Candidate ...
Oct 23, 2025 · We present the discovery of GJ 251 c, a candidate super-Earth orbiting in the habitable zone (HZ) of its M dwarf host star.
[56]
Detailed Architecture of the L 98-59 System and Confirmation of a ...
Aug 8, 2025 · A New Habitable Zone Exoplanet in the Vicinity of the Earth. The newly confirmed exoplanet L 98-59 f with a period of 23.064 ± 0.055 days and ...
[57]
Astronomers Confirm Fifth Exoplanet in L 98-59 System | Sci.News
Jul 23, 2025 · Named L 98-59f, this planet is a non-transiting super-Earth with a minimal mass of 2.8 Earth masses on a 23-day orbit inside the habitable zone of the small ...
[58]
TOI-6894 b - NASA Science
TOI-6894 b is a gas giant exoplanet with a mass of 0.168 Jupiters, orbiting its star in 3.4 days at 0.02604 AU. It was discovered in 2025.
[59]
Giant Exoplanet Found Orbiting Low-Mass Star TOI-6894 | Sci.News
an exoplanet around 86% the size of Jupiter in orbit around a 0.2-solar-mass red dwarf — highlights the need ...
[60]
Nine new M dwarf planet candidates from TESS including five gas ...
TESS has detected ∼ 450 M dwarf planet candidates, including two Earth-sized planets in the habitable zones of M dwarfs (TOI-700d and e; Gilbert et al. 2020).
[61]
The habitability of stagnant-lid Earths around dwarf stars
We compute the boundaries of the habitable zone around M-, K-, G-, and F ... distance of 0.04 au for the M dwarf AD Leo (≈20%) and 0.4 au for the F ...
[62]
A Reappraisal of The Habitability of Planets around M Dwarf Stars
Tidally locked synchronous rotation within the narrow habitable zone does not necessarily lead to atmospheric collapse, and active stellar flaring may not be as ...<|separator|>
[63]
Extreme Water Loss and Abiotic O2 Buildup on Planets Throughout ...
During this early runaway phase, photolysis of water vapor and hydrogen/oxygen escape to space can lead to the loss of several Earth oceans of water from ...
[64]
Exoplanets Need to be Prepared for Extreme Space Weather ...
Jan 16, 2025 · Red dwarf stars are the most common stars in the universe and live ... The combined effects of the steady X-ray and UV radiation and the flares ...Missing: erosion | Show results with:erosion
[65]
Habitability and sub glacial liquid water on planets of M-dwarf stars
Apr 14, 2023 · A new study shows that subglacial melting may provide an answer, significantly extending the habitability region, in particular around M-dwarf stars.
[66]
A first look at rocky exoplanets with JWST - PNAS
Nearly all of the feasible targets orbit small, M-dwarf host stars—these are the most numerous rocky planets in the Galaxy, and also the easiest to characterize ...
[67]
Why M-dwarf flares have a limited impact on the atmospheric ...
We find that flares have a modest impact on the cumulative atmospheric mass loss - less than a factor of 2 - with the greatest absolute increase occurring when ...Missing: erosion | Show results with:erosion
[68]
The Atmospheric Circulation and Climate of Terrestrial Planets ...
In this work, we investigate the atmospheric circulation and climate of terrestrial exoplanets orbiting both Sun-like and M dwarf stars over a wide swath of ...Missing: mitigation | Show results with:mitigation