- Press Release
- Oct 6, 2022
NASA’s Ames Research Center Uses Transit Photometry to Confirm Existence of Extrasolar Planet Circling HD 209548.
[21 Dec 1999] Researchers at NASA ARC announced that their Vulcan Camera Project has used transit photometry to confirm the existence of a previously identified planet orbiting the star HD209458. This planet was originally discovered at UCAR’s High Altitude Observatory in Boulder, Colorado in November 1999. The planet was calculated to have a mass 1.3 times that of Jupiter in an orbit about its parent star that required only 3.52 days. This is typical of the so-called “hot Jupiters” that have been discovered thus far.
The technique of transit photometry involves measuring the change in a star’s brightness as an orbiting planet moves across or ‘transits’ its face. Great care is needed so as to separate local atmospheric disturbances in a star’s light from actual light level changes coming from the target star itself.
By coincidence, such a transit recently occured in our own solar system when Mercury transited the face of our local star (“Of Planetary Transits Near and Far“).
Also, by coincidence, it was recently announced (“ESA’s Hipparcos Satellite Observed an Extrasolar Planet 8 Years Ago.“) that observing star light changes (in this case observations of the very same star HD 209548 – albeit 8 years after the fact) from satellites can also be used detect extra solar planets.