Wobbly stars

[fluffymark]

At long last, the Astrometric wobble (as opposed to the Doppler shift) of a star due to an orbiting planet has finally been detected using the Hubble Space Telescope. Yay! (Benedict et al. 2002)


True, the planet was already known (Gliese 876b), actually finding an unknown planet by astrometry would be more impressive. However the result is still a breakthrough, as the inclination of the orbit of the planet can be directly measured, and the mass calculated for the first time. They find the mass of Gliese 876b to be 1.89 Jupiter masses. Which is damn near spot on the mass I said it must have (1.92 Jupiter masses, Snellgrove et al. 2002) in order for the resonant interaction with Gliese 876c (a second planet) and also the surrounding protoplanetary disk in order for it to have obtained the observed orbital eccentricity.

Go me!!!! Everything is slowly falling into place......

Comments

[mirabehn.livejournal.com]

Yay! That's really exciting. I do sort of understand it, having been brought up watching lots of science documentaries, especially those to do with astronomy and planets and things. I knew they were trying to do stuff with wobbles...

1.89 Jupiter masses. A big planet. Hmmmm...

Well done for predicting the mass so well! Wow. Am very impressed, actually. :-)

*smiles*

Elly