NASA Announces Plan to Map Milky Way With Roman Space Telescope

NASA's Nancy Grace Roman Space Telescope team has released detailed plans for a major survey that will reveal our home galaxy, the Milky Way, in unprecedented detail. In one month of observation spanning two years, the survey will reveal tens of billions of stars and explore previously unexplored structures.

“The Galactic Plane survey will revolutionize our understanding of the Milky Way,” said Julie McEnery, Roman senior scientist at NASA Goddard Space Flight Center in Greenbelt, Maryland. “We will be able to explore the mysterious far side of our galaxy and its star-studded heart. With the breadth and depth of exploration, this will be a true scientific mine.”

“Galactic Plane Review” is the first project chosen by Roman. general astrophysical review is one of many surveillance programs that Roman will be doing in addition to his three main surveys And Coronagraph technology demonstration. At least 25% of Roman's five-year core mission is dedicated to astronomers around the world so that they can offer additional research beyond the core programs, taking full advantage of Roman's capabilities to conduct groundbreaking scientific research. The novel is scheduled to launch by May 2027, but the team plans to launch it as early as fall 2026.

While ESA (European Space Agency) retired Gaia The spacecraft has mapped about 2 billion stars in the Milky Way in visible light, with many parts of the galaxy remaining hidden by dust. Surveying in infrared light, Roman will use powerful thermal vision that can penetrate the veil and see what lies beyond.

“I'm just amazed that for the first time we'll be able to see the densest part of our galaxy and study it properly,” said Rachel Street, a senior scientist at Las Cumbres Observatory in Santa Barbara, California, and co-chair of the committee that selected the galactic plane survey project.

The study will cover nearly 700 square degrees (an area of ​​sky the size of about 3,500 full moons) along the Milky Way's luminous band, our survey of the disk-shaped structure containing most of our galaxy's stars, gas and dust. Scientists expect the study to map up to 20 billion stars and detect tiny changes in their positions through repeated high-resolution observations. And it will only take 29 days during the first two years of the mission.

Space cradles

Stars are born from parent clouds of gas and dust. Roman will peer into the haze of these nests and see millions of stellar embryos, newborn stars still shrouded in a veil of dust, hysterical baby stars that flare unpredictably, and young stars around which planetary systems may be forming. Astronomers will study the birth rate of stars over a wide range of masses and collect videos showing how stars change over time.

“This study will study such a huge number of stars in so many different stellar environments that we will be collecting samples at every stage of a star's evolution,” Street said.

Observing so many stars at different stages of early development will shed light on the forces that shape them. Star formation is like a four-way tug of war between gravity, radiation, magnetism and turbulence. The novel will help us study how these forces influence whether gas clouds collapse into full-fledged stars, smaller brown dwarfs—intermediate objects that are much heavier than planets but not massive enough to ignite like stars—or into new worlds.

Some stars are born in huge litters called clusters. The novel will be studied by about 2,000 young, loosely connected people. open clusters to see how the spiral arms of a galaxy cause star formation. The research will also map dozens of ancient, densely located globular clusters near the center of the galaxy, which could help astronomers reconstruct the early history of the Milky Way.

Comparing Roman's images of clusters scattered throughout the galaxy will allow scientists to study nature and nurture on a cosmic scale. Because stars in a cluster typically have the same age, origin, and chemical composition, analyzing them allows astronomers to isolate environmental effects very precisely.

Pulse check

When stars like the Sun run out of fuel, they leave behind cores called white dwarfs and heavier stars collapse, forming neutron stars And black holes. Roman will find these star embers even when they are alone thanks to wrinkles in space-time.

Anything that has mass distorts the underlying fabric of the universe. When light from a background star passes through the gravitational well around an intermediate object on its way to Earth, its path bends slightly around the object. This phenomenon is called microlensingcan temporarily make a star brighter. By studying these signals, astronomers can learn the mass and size of otherwise invisible foreground objects.

Separate survey – Romana Time-domain study of a galactic bulge — will conduct deep observations using microlensing over a smaller area in the center of the Milky Way. The Galaxy Plane Survey will make repeated observations over a shorter interval, but across the entire center of the galaxy, giving us our first comprehensive view of this complex galactic environment. An unobscured view of the galaxy's central band will help astronomers answer questions about its origins, and Roman's videos of stars in the region will allow us to study some of the ultra-dense binaries at the very end of their lives through their interactions with nearby satellites.

“Compact binaries are particularly interesting because they are precursors to gravitational wave sources,” said Robert Benjamin, a visiting professor at the University of Wisconsin-Whitewater and co-chair of the committee that selected the galactic plane exploration project. When neutron stars and black holes merge, the collision is so powerful that it causes oscillates in the fabric of space-time. “Scientists want to know more about the pathways that lead to these mergers.”

Repeated observations of Roman will also make it possible to track twinkling stars. Ground-based surveys detect thousands of bright stellar flares, but often fail to see the dim, dust-shaded stars that produce them. Roman will identify those responsible and take high-resolution photographs of the consequences.

Some stars pulsate rhythmically, and the rate at which they pulsate is directly related to their internal brightness. By comparing their true brightness with how bright they appear from Earth, astronomers can measure distances across the galaxy. Roman will find these blinking stars further out than ever before and track them over time, helping astronomers improve their space-based measuring instruments.

“Combining Roman's Galactic Plane survey with other observations of the Milky Way will create the best portrait of the galaxy we've ever had,” Benjamin said.

Download additional images and videos from NASA's Science Visualization Studio.

For more information about the Rome Space Telescope, visit:

https://www.nasa.gov/roman

Ashley Balser
NASA Goddard Space Flight CenterGreenbelt, Maryland.

Media Contact:

Claire Andreoli
NASA Goddard Space Flight CenterGreenbelt, Maryland.
301-286-1940