instrument

roman

NASA's Nancy Grace Roman Space Telescope, a future observatory for dark energy and exoplanets.
28 related articles

Description

The Nancy Grace Roman Space Telescope, formerly known as WFIRST, is a NASA observatory scheduled for launch in the late 2020s. It is designed to address fundamental questions in cosmology, particularly the nature of dark energy, and to discover and characterize exoplanets. With a wide field of view and infrared capabilities, Roman will survey large areas of the sky, complementing the James Webb Space Telescope's deep, narrow views.

History

The telescope is named after Nancy Grace Roman, NASA's first chief of astronomy, who was instrumental in the development of the Hubble Space Telescope. The mission was first proposed in the 2000s as the Joint Dark Energy Mission and later renamed WFIRST before being renamed again in 2020.

How it works

Roman's primary instrument is a 2.4-meter mirror (the same size as Hubble's) equipped with a wide-field infrared camera. It will measure the positions and shapes of hundreds of millions of galaxies to map the distribution of dark matter and trace the expansion history of the universe. For exoplanets, it will use microlensing to detect planets by the gravitational bending of light from background stars, and it will also directly image giant planets using a coronagraph to block starlight.

In practice

Roman will provide data for dark energy studies, exoplanet demographics, and infrared surveys of the Milky Way and nearby galaxies, serving the broader astronomical community.

Fun fact

Roman's field of view is 100 times larger than Hubble's infrared camera, allowing it to map the sky much faster.

Concept graph →

Related articles · 28

Cosmology2026-08-072 minarXiv:2608.07453express
How Much Light Hides in Ancient Heat
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Galaxies2026-08-072 minarXiv:2608.07461express
A Cosmic Wanderer Posing as a Galaxy
A distant light in the fog looks tiny and reddish: you'd think it's miles away. But then the light shifts sideways, and it becomes clear: it's a cyclist twenty steps away, just with a nearly dead rear light. That's how, in 2025, astronomers stumbled upon 'Capotauro'—a compact red source in images from the James Webb Space Telescope.
Galaxies2026-07-223 minarXiv:2607.20606
Galactic Exhalation: Neutral Gas Leaves Massive Galaxies in the Early Universe
The JWST spectrograph caught a barely perceptible dip in the spectrum of a distant galaxy — two lines, like shadows cast by cold gas. These are the sodium lines, the very yellow light of streetlamps. Here, at the edge of the visible Universe, they betray the slow exhalation of a galaxy returning matter to space.
General Relativity2026-07-192 minarXiv:2607.17252express
How the newborn cosmos brewed helium
The first three minutes after the birth of the world are a cosmic kitchen where nature cooked the lightest atomic nuclei. The recipe is set by gravity: it controls the cooling rate of the hot 'broth' of particles. If gravity worked differently than we are used to, the dish would have turned out different — with different amounts of helium and deuterium.
Galaxies2026-07-101 minarXiv:2607.09460express
Cosmic Mirages: What Was Really Behind the 'Dyson Spheres'
In 2024, the Hephaestus project sifted through millions of stars and flagged a few dozen suspicious ones: they shone brighter in the mid-infrared than a normal red dwarf should. Two of these candidates, labeled D and E, looked especially tantalizing, as if an invisible heater were working next to the star.
Invisible Planet in Warped Light
The light of a distant star is no perfect beacon. Passing through the gravitational field of another star, it bends, splits, and magnifies, creating a fleeting Einstein ring in the sky. This is how gravitational microlensing manifests, predicted by Fritz Zwicky back in the 1930s.
Stellar2026-06-292 minarXiv:2606.30112express
A Cosmic Dance of a White Dwarf and a Brown Dwarf
The James Webb Space Telescope has peered into a strange binary world. Here, a dead star, a white dwarf, slowly roasts its companion, a brown dwarf. The object, named ZTFJ0038+2030, completes a full orbit in just a few hours. One side of the brown dwarf always faces the white dwarf, much like the Moon faces Earth.
Astrons: Electric Leviathans That Defy Cosmology
In the searing plasma of the newborn Universe, when space itself still rang with the echo of the Big Bang, objects may have emerged that challenge gravity itself. Not ordinary black holes — but electrically charged giants, astrons.
Instrumentation2026-05-051 minarXiv:2605.04133express
How to Peer into the Heart of a Black Hole
Einstein's theory of gravity explains how mass warps space and time. Its predictions have been tested near Earth, but the most grueling tests lie around black holes, where distortions reach their breaking point. Until now, astronomers saw them as blurry smudges on an underexposed photo.
HEP Phenomenology2026-04-282 minarXiv:2604.26004express
A Window for Invisible Particles: Axions Are Back
In 1987, astronomers saw a supernova flare up in a neighboring galaxy — the Large Magellanic Cloud. It was a rare gift: the explosion was close enough to catch not just light but also neutrinos, those nearly undetectable particles that pass straight through Earth.
Exoplanets2026-04-232 minarXiv:2604.21848express
Planet's Breath: How Gas Flows Reveal the Secret of Life
The smell of fresh bread unmistakably signals a nearby bakery. But to know if baking is happening right now, it's better to catch not the aroma itself but its intensification — the continuous stream of hot air from the oven. This everyday analogy helps grasp a revolution in the search for extraterrestrial life on exoplanets — planets beyond our solar system.
Instrumentation2026-04-221 minarXiv:2604.20182express
A Swarm of Tiny Sails Heads to Proxima b
A handful of coins accelerates to one-fifth the speed of light. That's what Coracle interstellar probes will be like — tiny spacecraft weighing just a few grams, each with an ultrathin sail film. A powerful laser beam pushes them forward: light presses on the sail like wind fills a yacht's sails, except instead of air, it's a stream of photons.
Galaxies2026-04-162 minarXiv:2604.14699express
Stellar2026-04-152 minarXiv:2604.13990express
A Solar Prominence Backlit
Above the Sun's limb hangs a cloud of tenuous, hot gas — a prominence. It can linger for weeks, then suddenly break loose and fly off into space. On April 15, 2023, the SPICE instrument on the Solar Orbiter probe got its first detailed look at such a cloud in ultraviolet light.
Cosmology2026-04-092 minarXiv:2604.07983express
Cosmic Lens Amplified a Star's Explosion a Hundredfold
A distant lamp shines through uneven glass. The glass bends the rays, and instead of one flame on the wall, several appear — some brighter, some fainter. In much the same way, a massive galaxy bends the light of an exploded star. There was one explosion, but the images show four glowing points.
Stellar2026-03-242 minarXiv:2603.22938express
The Mystery of Gamma Cassiopeiae: Half a Century to Solve the X-ray Phantom
For half a century, astronomers puzzled over the nature of the powerful X-ray emission from Gamma Cassiopeiae — a bright beacon in its constellation whose X-ray glow didn't fit models of single stars. An invisible companion was suspected, but direct evidence was lacking.
Exoplanets2026-01-161 minarXiv:2601.11469express
Invisible Lens Reveals a Planet 40 Times the Mass of Earth
One night, a star at the edge of the sky suddenly flickered and brightened for a few days. It wasn't a supernova, and no cloud passed by — an invisible planet drifted between the star and Earth. Its gravity bent the light of the distant star like a pair of glasses focusing a sunbeam.
Instrumentation2026-01-121 minarXiv:2601.08883express
The Colors of Life on Distant Planets
To spot life on other planets, you don't necessarily need to search for oxygen in the air. Living beings paint the surfaces of their worlds: Earth's plants in green, bacteria in purple. The future HWO space telescope will capture these "paints of life" on exoplanets.
Galaxies2026-01-051 minarXiv:2601.02469express
First Stars: Fireworks Seen by Webb
The James Webb Space Telescope spotted bright points of light from an era just 100–300 million years after the Big Bang. At first they were taken for distant galaxies, but now a hypothesis suggests they might be lone fireworks — explosions of the very first stars.
Instrumentation2025-11-291 minarXiv:2512.00492express
Mission: Catch a Guest from Another Star System
The Comet Interceptor mission launches without a target. The spacecraft freezes at a point of space equilibrium, like a fighter jet on combat standby: engine warmed up, but takeoff only on alert.
Exoplanets2025-11-181 minarXiv:2511.14407express
New Schedule for Faraway Worlds
A bus schedule drifts: if you don't check it, you'll miss your ride. Planets around other stars have the same problem – their crossings of the star's disk gradually shift. The ExoClock project pooled 30,000 observations from Earth and space to refine the schedule for 620 distant worlds. For 45% of the planets, transits were found to be off by hours.
Exoplanets2025-10-281 minarXiv:2510.24575express
The Hunt for Moons of Rogue Planets
In the vast darkness of interstellar space, the rogue planet WISE 0855 flickers with a barely perceptible heat glow, like a cooling ember. Its temperature is only a few dozen degrees above freezing — if life existed there, it would see a sunless sky, in an eternal icy haze.
Exoplanets2025-10-161 minarXiv:2510.14229express
Sulfur in the Sky of a Warm Neptune: Sulfur Dioxide in the Atmosphere of HAT-P-26 b
In 2023, the James Webb Space Telescope turned its gaze toward a distant star in the constellation Virgo. Orbiting it is HAT-P-26 b, a warm Neptune, a world with a mass of 18.6 Earths and a radius of 6.33 Earths. The planet transited across the star's disk, and at that moment its atmosphere became briefly visible.
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In October 2017, the Pan-STARRS telescope in Hawaii spotted an object moving too fast to belong to the solar system. It was 1I/ʻOumuamua, the first interstellar visitor ever recorded by astronomers. Since then, two more have joined it: comet 2I/Borisov and object 3I/ATLAS.
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In August 2024, the MIRI coronagraph on the James Webb Space Telescope stared at Alpha Centauri A, the nearest Sun-like star to our Sun. At 1.5 arcseconds from the star, a point source, S1, blinked into view. Flux: 3.5 mJy, contrast: 5.5×10⁻⁵. Four to six sigma. A lighthouse flashing in the fog.
Instrumentation2024-11-292 minarXiv:2412.00159express
Night Flashes: Hunting for Split-Second Signals
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