TL;DR: NASA and ESA are sensing the universe across infrared, visible, and ionized gas tracers, with Webb resolving star birth in NGC 7129 and N159 and Hubble surveying low-mass satellite galaxies including NGC 1827.

Sensing across messengers, not just visible light

Astronomers now study cosmic objects with light, particles, and space-time ripples called gravitational waves, and combining those channels yields more than any single channel alone, an approach scientists call multimessenger astronomy, according to NASA Science publication titled Sensing the Universe.

In that framework, scientists describe light as streams of photons, the smallest packets of light energy, with behavior like both particles and waves, and they organize types of light by energy, wavelength, and frequency into the electromagnetic spectrum.

Radio waves sit at the lowest-energy, lowest-frequency, longest-wavelength end, and the universe contains radio-emitting pulsars, nebulae, and some galaxy types, while everyday terrestrial uses include cell phones and wireless internet transmission.

Microwave light informs study of galaxy structure, including the Milky Way, and NASA's Cosmic Background Explorer mapped the cosmic microwave background, described as a baby picture of the universe.

Infrared light traces heat and dust between stars and newborn stars, and NASA's James Webb Space Telescope uses infrared to examine very old stars, while visible light detected by eyes is emitted by fireflies, lightbulbs, and stars and is used by NASA's Transiting Exoplanet Survey Satellite to locate worlds beyond the solar system.

Ultraviolet light carries more energy than visible light, most is blocked by Earth's atmosphere although some solar ultraviolet reaches the surface, and NASA's Hubble Space Telescope uses ultraviolet to examine subjects from Jupiter's auroras to star formation in other galaxies.

X-rays penetrate deeply enough for dental imaging and airport baggage screening, and astronomers use missions including NASA's Chandra X-ray Observatory to study neutron stars, galaxies, and cosmic explosions.

Gamma rays are the highest-energy form of light, used terrestrially to sterilize food and medical equipment and treat some cancers, and astrophysicists use them to investigate massive-star explosions and neutron-star and black-hole collisions, with NASA's Fermi Gamma-ray Space Telescope collecting gamma rays for more than a decade and identifying two large gamma-ray bubbles extending thousands of light-years above and below the center of the Milky Way.

Webb peers through dust in NGC 7129

A new image from NASA's James Webb Space Telescope revealed numerous stars previously hidden by dust in the stellar nursery NGC 7129, about 3,300 light-years from Earth, according to the NASA Science report titled NASA's Webb Captures Commotion From Nebula's Stellar Jets.

Because young stars sit inside cold, dense molecular clouds of dust and gas, they can be impossible to view with telescopes insensitive to infrared light, while Webb's infrared sensitivity lets astronomers look through that dust and examine early phases of stellar life cycles.

The report describes hot atomic hydrogen gas in a golden zone and cooler molecular hydrogen, shocked by embedded protostars, in red, with stars in the cluster occupying different developmental stages and the more massive examples forming and evolving fastest.

The region's most massive and most mature member is the luminous central star LkH(alpha) 234, pronounced Lick-H-alpha, a pre-main-sequence star estimated at 5 to 8 times the mass of the Sun.

Pre-main-sequence stars of that kind have largely completed mass accumulation and are contracting under gravity, raising temperatures, and the central object is expected eventually to fuse hydrogen as the Sun does.

To the left of that star lies a gold-colored cavity spanning about 3.5 light-years, the largest visible imprint of the central star, excavated when outflows from an earlier phase of its life cut into the dense hydrogen molecular cloud.

Both those earlier outflows and present starlight energize the gas and make it glow, much hydrogen is expelled while a substantial amount is compressed, establishing conditions in which additional stars can develop.

Winds, bow shocks, and a chemical boundary

Several stars appear inside the cavity, according to the same NASA Science report, with several in the pre-main-sequence phase releasing stellar winds.

Where those winds press into excited surrounding gas, curved compressed structures called bow shocks appear near the stars and shape smaller cavities of their own.

Together, the central star and embedded stars also maintain the sharp ridge seen at the top of the golden cavity, where their radiation sustains a hot zone that pushes against colder, denser molecular gas beyond the cavity.

That interface is a photodissociation region, where hydrogen molecules are broken into atoms, and by altering temperature and chemistry the stellar group shows how molecular clouds erode across millions of years.

The material to the right of the central star tells a younger story, with clumpy red matter concealing protostars, objects at a stage before the pre-main-sequence phase that follows initial compression and fragmentation of molecular gas and dust clouds.

As those protostars gain matter and mass, they expel superheated outflows that strike the dense, gray, translucent envelopes around them, producing shocks and a textured appearance, with overlapping outflows from multiple stars creating a chaotic visual field and red emission from the interaction.

Near the upper left, a blue-tinted nebula contains a protostar encircled by a donut-shaped material disk, and that disk throws a shadow onto surrounding nebulosity in a configuration compared with the Bat Shadow previously recorded by NASA's Hubble Space Telescope.

Webb's high spatial resolution exposes detailed filaments in gas and dust and numerous background galaxies, extending earlier work by NASA's retired Spitzer Space Telescope, and astronomers will continue using the Webb measurements to examine how regional stars and protostars affect nearby gas and dust.

A different nursery in a neighboring galaxy

ESA's Picture of the Month from the NASA/ESA James Webb Space Telescope shifts attention to LHA 120-N 159, called N159, about 161,000 light-years distant in the Large Magellanic Cloud, one of the satellite galaxies orbiting the Milky Way, according to the ESA report titled Stars brewing in a nebulous cauldron.

The pictured field spans about 230 light-years and was recorded with Webb's Near-Infrared Camera, showing a turbulent star-formation environment inside dense gas clumps.

N159 belongs to the class of ionized-hydrogen zones where giant cold hydrogen molecular clouds collapse gravitationally and produce new stars, many extremely massive and hot, whose powerful ultraviolet radiation ionizes nearby gas.

Because ionized gas radiates, such zones become brilliant emission nebulae and serve as markers of active star formation, while fierce stellar winds sculpt dense ridges and carve cavities in the gas.

Thick smoky-orange clouds enclose and cross the center of the scene, with light-orange color indicating emission from polycyclic aromatic hydrocarbons, described as an important carbon-based molecule.

Pale-blue pools represent ionized hydrogen gas excited by intense ultraviolet light from massive stars, while dark-red filaments crossing the center, especially above the blue area on the right, consist of cool molecular hydrogen.

Those filaments form the densest portion of the nebula and presently shield embryonic stars from harsh radiation and stellar winds, yet close inspection shows points of stellar light embedded in the filaments and in small orange gas pillars extending into blue bubbles, structures expected eventually to dissipate and leave completed stars behind.

The Large Magellanic Cloud contains many comparable ionized-hydrogen zones available for study, including the larger N79 region and the Tarantula Nebula, and its star-forming environments differ from those in the Milky Way in metallicity, meaning the proportion of elements.

Hubble places star formation in galactic context

While Webb dissects individual nurseries, NASA's Hubble Space Telescope continues placing low-mass galaxies in their larger galactic setting, according to the NASA Science report titled NASA's Hubble Spies Spiral's Edge.

That report presents the edge-on intermediate spiral galaxy NGC 1827, roughly 37 million light-years away in the constellation Columba, the Dove, with rusty-brown dust lanes running lengthwise.

The observation used Hubble's Advanced Camera for Surveys and shows bright-blue zones along the disk interspersed with dark dust lanes where new stars are likely forming.

Distant galaxies speckle the black background, while foreground stars nearer than the target are recognizable by diffraction spikes, including a bright foreground star just left of the galaxy's bright central bulge whose four spikes arise when light bends around internal supports holding Hubble's secondary mirror.

The image belongs to a survey of 260 satellite galaxies around 22 Milky Way-like hosts within about 32 million light-years of Earth, of which Hubble has observed 111, with one orbit devoted to each remaining galaxy for 149 additional orbits.

Low-mass galaxies in the program offer a test of cosmological-model predictions on small scales, an area where models struggle to match observations, and the accumulating measurements are intended to help researchers describe low-mass galaxies in Milky Way-like systems and refine cosmological models.

Particles and ripples complete the sensing toolkit

Light alone does not exhaust the available signals, because many objects and events also eject high-speed particles that can emerge from dense settings, such as dying stars, where even light struggles to escape.

Cosmic particles divide into neutrinos and cosmic rays, with neutrinos produced by radioactive decay and nuclear reactions in Earth-based reactors, stellar cores, supernova explosions, and tidal shredding of stars by black holes.

Neutrinos are fundamental particles that cannot be subdivided, they outnumber all atoms in the universe, travel at nearly light speed, and interact rarely with other matter, qualities that make them scientifically valuable and difficult to detect.

The National Science Foundation's IceCube Neutrino Observatory in Antarctica instruments a cubic kilometer of ice, yet records only one neutrino every six minutes, or one for every 500 trillion trillion passing through in the same interval.

Cosmic rays are charged, high-energy particles moving near light speed, striking every square meter of Earth's atmosphere every second in large numbers, usually as hydrogen nuclei or protons, although neutrons, electrons, antimatter, and heavier nuclei such as cobalt or barium measured by NASA's balloon-borne Super Trans-Iron Galactic Element Recorder have also been found.

They gain speed in energetic settings, including expanding supernova shock-wave debris, but because they carry positive or negative charge, magnetic fields of stars and other bodies can deflect their routes through space.

Gravitational waves, the third messenger family, are ripples in space-time that move at light speed and arise when objects accelerate, decelerate, or change configuration, extending sensing beyond electromagnetic and particle detectors.

Sources referenced