HPF will help Researchers to Find New Planets

Astronomers are going to use a new spectrograph, called Habitable Zone Planet Finder (HPF), to study infrared signals from nearby stars that will allow them to detect planets with liquid water on them.

The Penn-State led HPF is designed with precision in mind. It is capable of providing the most precise measurements of infrared signals to date. Astronomers from institutions like the University of California have already begun using HPF to detect habitable planets outside our solar system. It measures subtle changes in a star’s color to seek out low-mass planets in the stars’ habitable zones. The slight color change is combined with measuring a star’s radial velocity as it is tugged on by a nearby orbiting planet. Even with its accuracy being best in class, HPF still requires assistance to explore the void. Paul Robertson, an Assistant Professor of Physics and Astronomy at UCI, talked about this spectrograph and said,

“About 70 percent of the stars in our galaxy are M-dwarfs like Barnard’s star, but the near-infrared light they emit has made it difficult for astronomers to see their planets with ordinary optical telescopes. With the HPF, it’s now open season for exoplanet hunting on a greatly expanded selection of stellar targets. It’s actually part of a suite of instruments attached to the Hobby-Eberly Telescope. Another crucial component is a laser frequency comb, developed by our collaborators at the National Institute of Standards and Technology.”

Location of HPF

The spectrograph is coupled to the Hobby-Eberly telescope, a 10-meter telescope located at McDonald Observatory in Texas. Mike Endl, an Astronomer at the observatory, explained the basic goal of the research by saying,

“We are especially interested in finding Earth-like planets that orbit in the habitable zone of the nearest stars. These planets represent our best chance to characterize and study them in greater detail. We might even be able to search for signs of life in their atmospheres in the near future with telescopes like the Giant Magellan Telescope and the James Webb Space Telescope. Since most stars are cool, red dwarf stars, we need a very precise instrument that is optimized for the near infrared. The laser frequency comb at the HPF enables us to reach this high level of precision to detect these small planets. It opens a new window in planet search that has predominantly focused on the visible bandpass to obtain highly precise Doppler measurements.”

How HPF works

The Habitable Zone Planet finder, as the name suggests, targets low-mass planets around cool M dwarf stars. They lie in the regions where liquid water may exist. The Hobby-Eberly Telescope uses near-infrared light at wavelengths near the visible spectrum to observe the dwarf stars. These dwarf stars are known to host rocky planets, which might have chances of harboring life on them. Suvrath Mahadevan, an Associate Professor of Astronomy and Astrophysics at Penn State, praised the technology of the spectrograph in the following words:

“The HPF was built to be incredibly stable, and we added a calibrator called a laser frequency comb to increase precision. The laser comb, which was custom-built by the National Institute of Standards and Technology (NIST), separates individual wavelengths of light into separate lines, like the teeth of a comb, and is used like a ruler to calibrate the near-infrared energy from the stars. This combination of technologies has allowed us to demonstrate unprecedented near-infrared radial velocity precision with observations of Barnard’s Star, one of the closest stars to the Sun.”

Hobby-Eberly Telescope

Recently, the Hobby-Eberly Telescope went through a $40 million upgrade as the Habitable Zone Planet Finder was added to it. According to Taft Armandroff, the Director of the observatory, HPF is a valuable addition and will be of particular importance for exoplanet hunting by the University of Texas faculty and will remain so for many years to come. The observatory is in partnership with the University of Texas and two German Institutions (Georg-August-Universität Göttingen and Ludwig-Maximilians-Universität München) and aims to continue the scientific investigations of exoplanets. Larry Ramsey, one of the Inventors of HPF, elaborated their intentions by saying,

“The research and development journey for precision instruments like the Hobby-Eberly telescope began in the 1980s at Penn State. Over the next decades, this led to the construction of several instruments that have greatly improved our ability to search for potentially habitable planets — from the Fiber Optic Echelle Instrument and the near-infrared Pathfinder instrument testbed to the powerful Habitable Zone Planet Finder, which has incredible spectral stability and the velocity sensitivity when coupled to the Hobby Eberly Telescope.”