It may not be impossible to find a particular grain of rice in a paddy field – if you have the right tools.
Garmina Singh, a postdoctoral fellow at the National Research Council Herzberg Astronomy and Astrophysics Research Center in Victoria, uses the grain of rice analogy to describe the difficulties of finding exoplanets orbiting stars dozens of light-years away from Earth. Earth.
Singh specializes in developing instruments and improving the technology used to directly image large, self-luminous exoplanets and seeks to help astronomers search for and image smaller, potentially Earth-like exoplanets.
She is currently involved in the development of a subsystem and the upgrade of a “planetary imager” instrument that worked with the Gemini South telescope in Chile, which works with the Gemini North telescope in Hawaii.
Singh and the researchers she works with are also developing an instrument for exoplanet detection and spectra retrieval, which will also be tested in Hawaii.
About 5,000 exoplanets have been discovered in the Milky Way galaxy so far, but only about 50 have been directly imaged.
“Currently, with current technology, we have been able to take direct images of…giant planets, which are self-luminous – they emit their own light – and they are far from their stars. When I say ‘far away’ they are more than 10 AU from their stars,” she said. “An AU is an astronomical unit, which is the distance between our sun and the Earth, so the planets that we took direct images of, they are super giant, self-luminous and they are very far from their stars. ”
Part of the difficulty in imaging smaller exoplanets is because the large telescopes needed to detect them are based on Earth. The extremely faint light detected by exoplanets – which is at least a million times fainter than their stars – must pass through Earth’s atmosphere, which bends and distorts the light, and there are other factors as well, such as vibrations in telescopes. What results is not a singular sharp dot-like image that can be easily discerned as a planet, but an array of spots or noise. The trick is to refine the image processing technology so that it can remove the noise to allow astronomers to spot the presence of an exoplanet.
The improved technology Singh is helping to develop will allow astronomers to image smaller exoplanets orbiting within 10 AU of their stars.
“The reason we’re not able to image an Earth-like planet or…planets on the scale of our solar system is because it’s hard to get rid of stains,” she said. “The spots look like planetary signals, but they are not planetary signals. These are false positives…because of several factors, including thermal distortions, temperature variations, misalignment. Even Earth’s atmospheric turbulence also introduces spots and they essentially hide planetary signals.
Prior to coming to Canada, Singh worked as a postdoctoral fellow at NASA’s Jet Propulsion Laboratory in Pasadena, California, and was a Marie Shlodowska-Curie Actions postdoctoral fellow at the Paris-Meudon Observatory in France.
In November, Singh will move to Hawaii to work at the Gemini North Telescope to ensure the calibration instrument works as expected.
Singh is the guest speaker at the Nanaimo Astronomy Society meeting on Thursday, October 27, when she will discuss direct imaging techniques and related challenges. For more information, visit http://www.nanaimoastronomy.com.
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