Where are the exoplanets?

PAGE IN PROGRESS

  • Where are the exoplanets in the sky?

The stars around which these planets orbit, or host stars, are uniformly distributed around the sky and can be found in all the constellations.

The GAIA SKY tool can be used to visit the sky in the hunt for exoplanets and other celestial objects.

On the exoplanets sky chart, the crosses show the positions of the known exoplanets in the skies of the northern and southern hemispheres. The selection gives the name of the star, its distance from the Sun in parsecs ? , and the number of planets detected around it. In the northern hemisphere, we can see a particularly dense zone corresponding to the search field of the Kepler satellite ? .

  • Are the exoplanets far from us?

The distance of these stars from Earth varies according to the detection method used.

  • Most of the exoplanets detected by direct imaging are less than 500 parsecs ? from the Sun, whereas the Galaxy ?  has a radius of 40,000 parsecs ? .
  • The radial velocity ? method, which provided most of the discoveries, also reveals exoplanets located a few tens of parsecs ? from us.
  • In the case of the other methods, the distance can be far greater, currently up to several thousand parsecs ? using transit photometry ?  or pulsar ? timing. The gravitational lensing method could detect planets at distances of several tens of thousands of parsecs ? .

It should be remembered that these are all stars within our Galaxy ? , and even then, just a small part of it, because the diameter of the Galaxy ? is estimated at about 100,000 light years ? . The planets in other galaxies ? are inaccessible, except possibly by using the gravitational lensing method.

  • The exoplanets in the Galaxy ?
Map of the exoplanets discovered (in 2015) in the Galaxy ? : Most of them are located close to the Sun, except for a few discovered using microlensing. The beam directed towards the top is the search field of the Kepler satellite ? .
(NASA/JPL-Caltech)

On the 3D map centred on the Sun, we can see exoplanets grouped in zones radiating out from the Sun. These zones are the fields of the search campaigns, for example those of Corot, Kepler (transit method) or OGLE (gravitational microlensing method).

This polar view shows the distances of the exoplanets from the Sun.