Roman’s primary mirror is 2.4 meters across—identical in size to Hubble’s—but it was originally built for U.S. spy satellites. Repurposed for civilian science, this mirror is paired with a 300-megapixel infrared Wide-Field Instrument and a high-contrast Coronagraph Instrument. Operating from a vantage point 1.5 million kilometers away, Roman will share the Lagrange point 2 neighborhood with the James Webb Space Telescope (JWST). This location provides a stable thermal environment crucial for the sensitive infrared observations required to peer through cosmic dust.
This unique hardware allows Roman to perform sweeping surveys of the cosmos. It will beam back 1.4 terabytes of data daily, accumulating roughly 500 terabytes annually. That yearly output matches the total data Hubble has produced over its entire 35-year lifespan. Managing this data deluge will be a monumental task, but it will allow astronomers to study large numbers of galaxies and stars simultaneously, enabling statistical analyses that were previously impossible.
Hunting Early Universe Black Holes
Among the newly approved General Investigator programs, several will target “little red dots” (LRDs). These compact, mysterious objects were first spotted by JWST in 2022 and might be exotic black hole stars or the dense beginnings of globular clusters. Strangely, LRDs seem to disappear as the universe ages, leaving their true nature a pressing question.
Vasily Kokorev of the University of Texas at Austin will lead a team to determine if LRDs actually fade over time or if they simply elude detection in older epochs. His team will begin their search two billion years after the Big Bang, looking for clues to their origin.
“When we try to find little red dots closer to us, we fail,” Kokorev says. He notes that using JWST for this task is like “trying to use an enormously large set of binoculars to read a book that’s right before you.” Roman’s wider view is essential for spotting these objects across vast stretches of sky. If they are indeed black hole stars fueled by dense gas cocoons, their numbers should drop as the universe expands and fuel runs dry. Alternatively, if they are the seeds of globular clusters, they should appear in similar numbers throughout cosmic history.
Mapping Deep Fields and Bright Galaxies
Steven Finkelstein, also at UT Austin, will hunt for exceptionally bright, distant galaxies similar to GN-z11. Discovered by Hubble in 2016, GN-z11 existed just 400 million years after the Big Bang. Although JWST has found older galaxies, GN-z11 remains uniquely luminous, making it easier to study in depth. Finkelstein hopes Roman will identify about 500 similar luminous objects.
“It’s so much brighter than one would have expected to form at early times,” Finkelstein says. His program will also spot LRDs and lensing clusters, which magnify the faint light of even older galaxies from the murky depths of cosmic time.
Finkelstein is also involved in the Roman eXtreme Deep Field (RXDF) project, led by Haojing Yan of the University of Missouri. This initiative will survey an area 140 times larger than Hubble’s extreme deep field. RXDF could reveal millions of galaxies dating back to 300 million years after the Big Bang.
Yan suggests Roman might even capture supernovae from the universe’s very first stars, known as Population III stars. “During most of their lifetimes, they are too faint to be detected,” Yan says. “But when they end their lives as supernovae, [with Roman] we’ll have a chance.”
Surveying the Andromeda Galaxy
Closer to home, Karoline Gilbert of the Space Telescope Science Institute will oversee a detailed survey of the Andromeda and Triangulum galaxies. Located 2.5 million and three million miles away, these neighboring galaxies are close and large enough for Roman to resolve individual stars.
Gilbert’s team aims to map half a billion stars across both systems. While Hubble and JWST can spot individual stars in these galaxies, Roman’s expansive field of view allows it to sift through Andromeda’s stellar population with unprecedented precision and breadth.
“Roman has this unprecedented combination of this panoramic view with really high resolution and precision,” Gilbert says. “We can study the ecosystem of these galaxies and the stars within them.”
By capturing repeated images over several years, Roman will track the subtle movements of stars in Andromeda, revealing the galaxy’s complex dynamical history. This will help astronomers understand how the galaxy formed and evolved over billions of years.
What Happens Next
As the Roman Space Telescope prepares for its August 30 launch, researchers are bracing for a data deluge that will require advanced processing pipelines and global collaboration. The observatory’s primary mission focuses on dark energy, dark matter, and exoplanet discovery, but these 118 supplementary programs will maximize its scientific output from day one. Over its five-year baseline mission, Roman is expected to uncover tens of thousands of exoplanets and capture over a million supernovae. Astronomers will soon have a panoramic window into both the deep cosmic past and our local galactic neighborhood, fundamentally shifting how we map and understand the universe.
— Priya Nair, science desk, AXO News