Study links planet spin to formation history
7 reported
Astronomers using the W. M. Keck Observatory on Maunakea, Hawai’i, have measured the spins of dozens of giant planets and brown dwarfs orbiting distant stars. Their survey included 32 gas giants and brown dwarf companions, including 6 planets larger than Jupiter and 25 brown dwarf companions. The observations revealed that giant planets can spin faster than much more massive brown dwarfs, challenging simple assumptions about mass and rotation. Researchers believe magnetic interactions early in the objects’ histories may explain the difference, with stronger magnetic fields slowing rotation over time. The findings were published in The Astronomical Journal and led by scientists at Northwestern University’s Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). The team used the Keck Planet Imager and Characterizer (KPIC) to isolate light from these distant worlds and measure subtle spectral broadening caused by rotation. Lead author Dino Chih-Chun Hsu described spin as a “fossil record” of how a planet formed. The team plans to expand the work by studying free-floating planets and using the upcoming HISPEC instrument, scheduled to begin operations in 2027.
What’s reported
The study used the W. M. Keck Observatory on Maunakea, Hawai’i.
The survey included 32 gas giants and brown dwarf companions, with 6 planets larger than Jupiter and 25 brown dwarf companions.
Researchers also incorporated previous spin measurements, creating a dataset of 43 stellar/substellar companions and giant planets, plus 54 free-floating brown dwarfs and planetary-mass objects.
In the HR 8799 system, a gas giant about 7 times Jupiter’s mass rotates six times faster than a brown dwarf companion roughly 24 times Jupiter’s mass.
The findings were published in The Astronomical Journal.
The team used the Keck Planet Imager and Characterizer (KPIC) instrument.
Future observations will use the HISPEC instrument, scheduled to begin operations in 2027.
Key figures
Dino Chih-Chun Hsu, lead author and researcher at CIERA (Northwestern University)
Jason Wang, Assistant Professor at Northwestern University and co-author
Matthew Williams, original writer for Universe Today
Sources: ScienceDaily
