Image Details
Caption: Figure 8.
The spectral index of V2400 Oph on 2019 April 25 and 2019 May 11, produced by fits of a power law to the X-band dynamic SEDs in Figure 7. In the first epoch (left), the spectral index is mostly stable, but in the second epoch (right), there is a clear evolution from flat to steep over ∼6 minutes.
© 2026. The Author(s). Published by the American Astronomical Society.