Chandra’s Dynamic Universe
Amruta Jaodand
The variable X-ray sky hosts some of the most energetic and fascinating phenomena in the Universe: exploding supernovae, outbursting X-ray binaries and accreting compact objects, rapidly variable stars, highly energetic jets, gravitational-wave mergers, flaring magnetars, sweeping fast radio bursts, gamma-ray bursts, fast blue optical transients, tidal disruption events, and changing-look AGN. This variability stretches across a broad range of timesales—from milliseconds to days, in some cases even extending to years. The environments in which variable phenomena can occur include crowded fields, the Galactic plane, nearby globular clusters and galaxies, and far-flung black holes. To investigate X-ray emission from these objects, we need excellent angular resolution, high-resolution spectra, and the ability to reach unprecedented sensitivities. In short, we need Chandra.
Chandra's unprecedented combination of angular and spectral resolutions offers unique diagnostic tools to study the underlying nature of transients and to maximise the discovery potential of the new transient-rich era of time domain astronomy. Chandra, with its sharp eye on the sky, localizes X-ray transients to arcsecond positions—allowing for identification of outbursting sources in crowded fields, resolution of point sources embedded in the Galactic center, and disentanglement of extra-galactic transients with other X-ray emitters in their vicinity. High-resolution Chandra grating spectra can also reveal the inherent nature of transient events, such as the tidal disruption event ASASSN-14li, wherein unexpected abundance ratios pointed to emission powered by the largest stars ever known to be shredded in a tidal disruption event.
Not only does Chandra allow for rapid follow-up of X-ray transients, but it is also an invaluable machine for long term monitoring of X-ray transients. It is the late-time X-ray emission from gravitational wave merger event GW170817 being detectable by Chandra approximately 2000 days post-merger that provides the strongest constraints on jet models. Likewise, late-time Chandra X-ray observations of fast blue optical transients such as AT 2024wpp show rising spectral evolution and, in combination with broadband X-ray and radio emissions, point to a complex progenitor involving super-Eddington accretion onto and mildly relativistic outflows from a compact object.
Chandra provides a powerful X-ray complement to current and future time domain and multi-messenger observational facilities. The Chandra X-ray Center has robust partnerships to coordinate joint observations with a broad assortment of multiwavelength facilities, currently including the NRAO, JWST, HST, Swift, NuSTAR, NOIRLab, and XMM-Newton. Considering the potential of current and upcoming TDAMM facilities—such as the Einstein Probe, the Roman observatory, the LIGO-Virgo-KAGRA gravitational wave detector network, and the Rubin observatory—the demand for Chandra observation time is only anticipated to go up.
We at the Chandra X-ray Center are thrilled to announce “Chandra's Dynamic Universe”—a science workshop focusing on unique breakthroughs in time domain astronomy driven by Chandra. The workshop is slated to take place in Cambridge, Massachusetts, from August 18–20, 2026. In this workshop we will highlight the numerous contributions Chandra has made to time domain astronomy and the new frontiers Chandra is poised to explore, and we will discuss strategies to efficiently enable these advances in view of the anticipated demand for the Chandra time. For more information about the workshop, please visit the website: https://cxc.harvard.edu/cdo/cdu/2026/.
The key workshop dates include:
| Abstract submissions open | March 12, 2026 |
| Registrations open | April 20, 2026 |
| Closing of abstracts for oral presentation | April 26, 2026 |
| Closing of abstracts for posters | June 18, 2026 |
| Registration deadline | July 10, 2026 |
| Start of the workshop | August 18, 2026 |
Please submit your abstract and join us! If you have any questions, please reach out through the conference email: cxcworkshop@cfa.harvard.edu. We look forward to seeing you this summer.