Planets bigger than their stars

[bdm]

APOD for 2009 June 3 was an artist's impression of a planet VB10 orbiting Van Biesbroeck's star. The planet is likely to be comparable in size to its parent star. The discussion also mentioned the possibility of planets that are larger than their parent stars.

This is an intriguing possibility. If such a planet exists, and we are in the orbital plane, we would see the planet blocking almost all the light from the star. Do such variable stars exist?

[selden]

BDM,

Observing transits is one of the ways exoplanets are detected. The light variations usually are quite small, though. I don't recall any announcements about significant eclipses.

[chris]

Since VB 10 b was detected astrometrically, there's little chance that it's orbital plane is aligned with the line of sight from Earth. The planet's gravity produces the largest apparent perturbations on the star's position when the line of sight is perpendicular to the orbital plane. This is in contrast to the radial velocity method, which works best when the light of sight is nearly parallel to the orbital plane. So, planets detected via the radial velocity method are much more likely to transit than astrometric planets.

--Chris

[ajtribick]

There are already the examples of the pulsar planets... neutron stars are tiny, so even a terrestrial planet would dwarf the star.

[bdm]

There are already the examples of the pulsar planets... neutron stars are tiny, so even a terrestrial planet would dwarf the star.

This is true. However, planets around main-sequence stars are more interesting.

[ajtribick]

However, planets around main-sequence stars are more interesting.

Why?

[selden]

Different people have different interests

( Personally, I'm annoyed when planetary candidates get removed from the list without saying *why* they were removed. Was it because the data were poor and could not be confirmed, or because they turned out to be brown dwarfs? )

[PlutonianEmpire]

If this turns out to be real, then Celestia's way of lighting up planets couldn't be more true.

[bdm]

However, planets around main-sequence stars are more interesting.

Why?

Because we live on one, of course.

[ajtribick]

On the other hand, we could not live on ANY of the planets we have found around main sequence stars either, even if we could get to them in the first place. None of them are particularly promising as candidates to host alien life either.

[eburacum45]

That artist's impression is very similar to the sort of quality you can get using Celestia nowadays. With a bit of post processing and the use of large enough textures I think it would be fairly easy to make an image like that.

[zhar2]

That artist's impression is very similar to the sort of quality you can get using Celestia nowadays. With a bit of post processing and the use of large enough textures I think it would be fairly easy to make an image like that.

Umm, i really dont know, celestia has a narrow options for graphics but on the otherhand that artistic impression isnt very challenging to do.