Comments on: Eyes On A Distant World

By: Robert Crowley

Robert Crowley — Sat, 02 Jul 2016 17:26:48 +0000

With such a long orbital period and radius, a large mass, and considering that the ‘parent’ star is still in the process of formation, is it possible that this object was captured from another system or is a ‘rogue planet’ that happened to stray too close to the star’s gravitational influence? If it is indeed gravitationally bound, as discussed in the above comments.

By: Jean Tate

Jean Tate — Sat, 25 Jun 2016 14:50:57 +0000

While some indirect tests may be possible within a year or so, and something can always come out of the blue, direct tests to show it’s gravitationally bound may take decades … you need proper motion, and preferably also radial velocity, both of which are really challenging for this object.

By: Troy Daniels

Troy Daniels — Fri, 24 Jun 2016 19:54:54 +0000

My first thought was, how do they know they planet is not being ejected from the system. Any estimate on how long it would take to conclusively show that it is gravitationally bound?

By: Brian Koberlein

Brian Koberlein — Thu, 23 Jun 2016 20:07:17 +0000

Yeah, it’s good to be skeptical about this one. For anything that is 660 AU out, determining whether it is gravitationally bound is tricky.

By: Jean Tate

Jean Tate — Thu, 23 Jun 2016 19:38:21 +0000

Nice result, but despite the efforts the authors made to rule out possibilities other than an orbiting planet, I think the case is still somewhat open.

Sure, it’s unfortunate that the object was in a diffraction spike, and yes, they made heroic efforts to get good data anyway, but I think it’s far from convincing. Also, as the ‘common proper motion’ test is not possible (neither object seems to have detectable proper motion), ruling out an unrelated object, with no detectable proper motion, is indirect. Finally, if both star and putative orbiting planet are young, the ‘standard object type’ tests can’t be all that definitive … young objects evolve rapidly.

By: geckzilla

geckzilla — Thu, 23 Jun 2016 18:11:55 +0000

Probably also worth noting that while both the star and planet appear to be resolved as round objects in this image, both are point sources and neither one is actually larger than a fraction of a pixel.