NASA
Chandra

Basics

Time domain and multimessenger (TDAMM) astronomy


The Chandra X-ray Observatory is unlike any other telescope. Since its launch into space on July 23, 1999, Chandra has been NASA’s flagship mission for X-ray astronomy in the fleet of “Great Observatories.” Chandra discovers exotic new phenomena and examines old mysteries, looking at objects within our own Solar System out to nearly the edge of the observable Universe.

“Time domain and multimessenger” (TDAMM) astronomy is predicted to be one of the most important areas in astrophysics in the coming decade. NASA’s Chandra X-ray Observatory is critical in TDAMM research. Sudden, short-lived, and changing cosmic phenomena (known as “transient events”) typically produce extreme energies and intense X-rays, many of which are located at large distances. Chandra is the only telescope that can provide the high sensitivity and unparalleled angular resolution needed to study these changing and evolving sources in X-ray light.

Fields as diverse as cosmology, accretion physics, and particle physics are heavily influenced by studies of transient phenomena, including the merging of neutron stars and the tidal disruptions of stars by supermassive black holes. Chandra works with telescopes across space as well as facilities on the ground to study these objects.

Chandra’s X-ray follow-up of ASKAP J1832−0911: an unusual long-period radio transient—helps probe one of the most mysterious new classes of objects in the time domain sky. These rare signals may point to exotic neutron stars or entirely new astrophysical phenomena.

Chandra’s X-ray follow-up of ASKAP J1832−0911: an unusual long-period radio transient—helps probe one of the most mysterious new classes of objects in the time domain sky. These rare signals may point to exotic neutron stars or entirely new astrophysical phenomena. Credit:X-ray: NASA/CXC/ICRAR, Curtin Univ./Z. Wang et al.; Infrared: NASA/JPL/CalTech/IPAC; Radio: SARAO/MeerKAT; Image processing: NASA/CXC/SAO/N. Wolk

Timing is Everything

The Universe is alive, changing over timescales of fractions of a second to billions of years.



Crab Nebula 1
Crab Nebula 2
Crab Nebula 3
Crab Nebula 4
Crab Nebula 5

Chandra’s X-ray snapshots of the Crab Nebula reveal a rapidly changing core, where a neutron star powers winds and shocks—key signatures in the time domain and multimessenger landscape. Credit: X-ray: NASA/CXC/SAO; Image processing: NASA/CXC/SAO/J. Schmidt, J. Major, A. Jubett, K. Arcand


To watch the story of the Universe unfold, astronomers use NASA telescopes in space and facilities on the ground. We build one-of-a-kind machines paired with the best software, AI, and know how. This enables the United States to lead this unprecedented era in cosmic exploration.

To understand what the gravitational waves meant, scientists immediately looked to the sky. Within moments of the signal, astronomers commanded telescopes around the globe to investigate. NASA’s Chandra X-ray Observatory, the world’s most powerful telescope, captured an X-ray signal in the exact spot where the gravitational waves came from – the first telescope to X-ray light from this event.

This detection was a moment frozen in time—capturing an event that had already happened over 100 millions years ago, but only now reached us. It gave scientists unprecedented information about an event a billion trillion miles away from Earth.

Putting the pieces of information together like a giant jigsaw puzzle, scientists were soon convinced that they had seen a rare cosmic event. The burst of gravitational waves and enormous flash of light, they determined, followed the merger of two neutron stars, some of the densest objects in the universe. Collisions like these play a crucial role in the evolution of the Universe.

This was just one example of how changes in space over time are important. Stars – including our Sun – are not static objects. In fact, they are constantly erupting and flaring, sending huge amounts of energy into space.

Other objects in space like black holes also change dramatically over different timescales from human lifetimes to galactic ones. From the giant black hole at the center of our Milky Way galaxy to smaller ones sprinkled through interstellar space, we need many eyes on the sky to track these unpredictable cosmic entities.

Humanity has learned so much about the Universe we all live in, but there is still far more we need to understand. The Universe reveals its secrets moment by moment. We all benefit from the knowledge gained – and the protection it can provide – by exploring the Universe through time.

Chandra detected the X-ray afterglow of a neutron star merger—marking the first time light and gravitational waves were seen from the same cosmic event. This milestone launched a new era of multimessenger astronomy, with Chandra playing a key role in tracking the evolving high-energy signal.

Chandra detected the X-ray afterglow of a neutron star merger—marking the first time light and gravitational waves were seen from the same cosmic event. This milestone launched a new era of multimessenger astronomy, with Chandra playing a key role in tracking the evolving high-energy signal.

X-ray: NASA/CXC/Northwestern U./W. Fong & R. Margutti et al. & NASA/GSFC/E. Troja et al.; Optical:NASA/STScI

By observing stars over time, we can track how they age, flare, and evolve—providing critical clues about the past and future behavior of our own Sun. This video shows a solar flare erupting from the Sun, captured by NASA’s Solar Dynamics Observatory.

UNLOCKING THE SECRETS OF THE UNIVERSE



Chandra can capture X-ray emissions from transient events like gamma-ray bursts, flaring from stars, and newly-discovered phenomena, allowing scientists to study their evolution over time.

Transient events
Chandra can capture X-ray emissions from transient events like gamma-ray bursts, flaring from stars, and newly-discovered phenomena, allowing scientists to study their evolution over time. More Info

By combining Chandra data with observations from other telescopes, gravitational wave instruments, and neutrino detectors, astronomers can get a more complete picture of the changing Universe.

Multi-messenger data
By combining Chandra data with observations from other telescopes, gravitational wave instruments, and neutrino detectors, astronomers can get a more complete picture of the changing Universe. More Info

Scientists can use Chandra to study tidal disruption events where black holes tear apart stars and other objects that wander too close.

Black hole studies
Scientists can use Chandra to study tidal disruption events where black holes tear apart stars and other objects that wander too close. More Info


Chandra can observe X-rays from colliding neutron stars that generate gravitational waves. It was, in fact, the first telescope to detect X-rays after a gravitational wave event.

Gravitational wave events
Chandra can observe X-rays from colliding neutron stars that generate gravitational waves. It was, in fact, the first telescope to detect X-rays after a gravitational wave event. More Info

Astronomers use Chandra to observe how the X-ray emission, representing important physical processes, from a supernova remnant changes over time.

Supernova remnants Monitoring
Astronomers use Chandra to observe how the X-ray emission, representing important physical processes, from a supernova remnant changes over time. More Info


More to Discover

TDAMM Handout

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