NASA has described peer-reviewed research into how a future space observatory could detect planets orbiting pairs of white dwarfs. A planet’s pull might leave a small modulation in the stars’ gravitational-wave signal. These are modelled detection possibilities, with infrared and positional observations proposed as complementary checks; the studies announce no planetary discovery.
NASA, the US space agency, has presented peer-reviewed research on a possible way to detect planets around double white dwarfs, pairs of stellar remnants. A planet’s gravitational pull could slightly alter the pair’s motion, leaving a modulation in its gravitational waves. The studies model a potential search; they do not announce a discovered planet. The account here rests on NASA’s announcement and its accompanying scientific paper.[1]
The proposed search would use the Laser Interferometer Space Antenna, or LISA, being developed by the European Space Agency with NASA contributions. Its three spacecraft are designed to operate two and a half million kilometres apart, measuring minute changes in separation with laser links. Launch is planned for the middle of the 2030s. White dwarfs in tight pairs should provide many of the continuous gravitational-wave signals available to the observatory.[1]
The companion paper considers infrared radiation from a planet and the positional wobble of its hosts as complementary observations. Its calculations compare a nominal four-year mission with ten years of observing. An infrared excess would not alone establish that a planet exists: material passing between the stars could also add light. Parameter uncertainty and systematic errors could reduce the sensitivity suggested by optimistic models. Combining different measurements could help investigate planetary systems after their stars’ late evolutionary stages.[1]
