Final answer:
The difficulty in detecting periodic flashes of radiation from celestial remnants like gamma-ray bursts arises because their afterglows fade too rapidly and they are not bright enough in the visible spectrum for telescopes like ROTSE to detect.
Step-by-step explanation:
The student's question seems to be addressing the challenges astronomers face when observing celestial phenomena such as gamma-ray bursts (GRBs), specifically the difficulty in detecting their afterglows.
The inability to observe periodic flashes of radiation from a celestial remnant may be because these afterglows fade away extremely quickly. For example, BeppoSAX and other satellites have tried, without success, to find afterglows from short-duration GRBs.
Additionally, even when using fast-responding visible-light telescopes like ROTSE, these bursts were not bright enough at visible wavelengths to be detected.
This underscores an essential concept in astronomy: relying exclusively on visible light for observations can be limiting since it is only a small fraction of the electromagnetic spectrum, and thus astronomers must utilize a wide range of instruments to capture the full picture of the universe.
In the context of the broader electromagnetic spectrum, other instruments besides visible-light telescopes are needed to observe different bands of radiation, including gamma rays.
For instance, the detection of gamma-ray bursts was first accomplished by the Vela satellites, which were designed to detect radiation from nuclear explosions but instead found these mysterious gamma-ray flashes coming from space.
Observing such phenomena requires sensitivity to a broad range of electromagnetic waves, not just those visible to the human eye, to avoid what's known as 'visible light chauvinism' in astronomy.
This holistic approach to observational astronomy allows for a more complete understanding of the universe.