RoPACS Science and Technology

A large number of science and technology facilities are potentially important to the RoPACS network. Each instrument and facility are suited to specialist techniques used to study rocky planets orbiting cool stars. The most important current and future technologies are presented on this page. Use the bookmarks listed below to jump to the relevant section.

Planetary transit analysis

Research is currently being carried out to detect rocky earth-like planets around cool stars using the near-infrared transit method. These primary reasons that cool stars are targeted for transit studies are as follows; firstly the habitable zone around cool stars is found at smaller radii than warmer stars. This means that transits of planets that can potentially sustain life are reasonably frequent. Secondly, the probability of detecting the change in brightness of a star during the transit of an earth-like planet is far higher when studying the coolest stars. A concise description of the near-infrared transit method can be read here. Two projects will be dedicated to discovering transiting earth-like planets; these are listed below.

Radial velocity analysis

The radial velocity technique is currently the most successful method used to detect planets orbiting stars. However, detecting earth-like planets using this technique is extremely difficult and requires a high level of precision. To accomplish this feat, highly stable infrared spectrographs are being developed which will yield measurements that are more precise than current technologies that use optical techniques on 8 to 10 metre class telescopes. These revolutionary instruments are listed below.

Detecting planetary light

With the use of space telescopes it is possible to directly detect light that is being reflected form earth-like planets that are orbiting stars. It is also possible to probe the properties of such objects. Space telescopes offer a significant advantage over ground-based telescopes due to the fact that they are orbiting above the earth's atmosphere. This means that telescopes perform close to their theoretical diffraction limit. Current space telescopes that are potentially useful to the RoPACS network are listed below.

  • The Hubble Space Telescope (HST)
  • The Spitzer Space Telescope (SST)

Direct imaging of planets can also be achieved with the use of cutting edge adaptive optics systems on 8 - 10 metre class telescopes. For further details follow this link.

Direct spectroscopic detection

Direct imaging techniques have great difficulty detecting planets due to the relative brightness of the parent stars and the extremely small angular separations in the sky. This can be overcome by spectroscopically studying the starlight that is emitted from the star. The starlight contains Doppler-shifted starlight that is scattered by a planet with a high orbital velocity. A schematic of this can be seen in this link together with a description of the process.

Future space missions

A number of future space missions will allow us to directly detect earth-like planets and study these objects in great detail. The capabilities of these exciting future missions are described in the links below