Ever thought that there should be some sort of instrument, apparatus, or telescope pointed at the sky solely for the purpose of detecting exoplanets? Surely, with all the resources and technology available, astronomers could — with adequate funding, of course — make this happen. Well, they have. A dedicated exoplanet imager, a telescope instrument whose sole reason to exist is to hunt the skies for planets revolving around other stars, has now entered the cosmic search for alien worlds.
Phys.org reported last week that Subaru Telescope on Maunakea, Hawaii, outfitted with an astronomical instrument — called the SCExAO (Subaru Coronagraphic Extreme Adaptive Optics) — designed to detect planets around other stars, has revealed its first images. After ten years of painstaking work, the SCExAO is finally operational and astronomers couldn’t be happier.
“Maunakea is the best place on this planet to see planets in other stellar systems. Now, we finally have an instrument designed to utilize this mountain’s special gifts and the results are breathtaking,” said Dr. Thayne Currie, the author of the first science result paper from SCExAO.
SCExAO at Maunakea will be the lead exoplanet imager, as two have already been commissioned in Chile and Arizona. It seems only appropriate, considering that the first planets ever imaged around another star were captured with general-purpose instruments at Maunakea.
SCExAO project leader Dr. Olivier Guyon said of the imager, “With SCExAO, we know not only the presence of a planet but also its character such as whether it is cloudy and what molecules it has, even if that planet is tens of trillions of miles away.”
The trio of AO systems are thus far responsible for roughly a dozen exoplanet discoveries. In fact, SCExAO at Maunakea — which, as the name suggests, has sharper, more “extreme” optics — may have already discovered the youngest debris disk ever encountered surrounding a star in the Taurus constellation. The star, designated HD 36546, appears to have a protoplanetary disk formed around a star estimated to be between 3 and 10 million years of age, a stellar body that appears to be associated with other relatively young stars.
“We barely flipped the ‘on’ switch for SCExAO and already saw a new planetary system,” Dr. Nemanja Jovanovic, who is also working on the instrument, said of the device. “The future, which includes a fully optimized SCExAO is extremely promising.”
The most recent images taken from the instrument indicate that the imager has been improved even further. The SCExAO at Maunakea is so sensitive it detects exoplanets (or planet-forming disks) in a minute, whereas other AO systems would need an hour for detection.
At present, the Kepler Space Telescope is the leader in the number of exoplanets discovered department. The Kepler, launched in 2009, has thus far discovered 4,696 candidate exoplanets to date. Of those, 2,331 have been confirmed.
According to the Extrasolar Planet Encyclopedia, there are a total of 3,575 exoplanets that have been discovered to date. (NASA claims 3,447 confirmed exoplanets to date.) These planets have been detected primarily through “transiting,” where the detected planet is revealed by noting the dimming of its parent star when the target planet passes between said star and the observer, and “radial velocity,” a method by which an exoplanet’s presence is deduced due to the displacement in the parent star’s spectral lines as a result of the Doppler effect.
At present, NASA has not only the Kepler Space Telescope but the Hubble Space Telescope and the Spitzer Space Telescope as well searching for alien worlds. In the future, missions like the James Webb Space Telescope, under construction and slated for a 2018 launch, and the conceptualized WFIRST (Wide-Field Infrared Survey Telescope) are designed to facilitate image-gathering of exoplanets.
[Featured Image by MarcelClemens/Shutterstock]