Guest speaker from the Nanaimo Astronomy Club will explain how images of exoplanets form from a series of spots – Nanaimo News Bulletin

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 rice grain analogy to describe the difficulties of finding exoplanets orbiting stars dozens of light-years from Earth.

Singh specializes in developing instruments and improving the technology used to directly image large, self-luminous exoplanets, and strives to help astronomers find and image smaller, potentially Earth-like exoplanets.

She is currently helping to develop a subsystem and upgrade of a “Planet Imager” instrument that was operated with the Gemini South Telescope in Chile, which is operated in conjunction with the Gemini North Telescope in Hawaii.

Singh and the researchers she works with are also developing an exoplanet detection and spectral retrieval instrument that will also be tested in Hawaii.

About 5,000 exoplanets have been discovered in the Milky Way so far, but only about 50 have been imaged directly.

“Currently, with current technology, we are able to take direct pictures of … giant planets that 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 Earth, so the planets we’ve taken direct pictures of are supergiant, luminous, and they’re very distant from their stars. ”

Some of the difficulties in imaging smaller exoplanets is that the large telescopes needed to detect them are ground-based. The extremely faint light captured from exoplanets – which is at least a million times dimmer than their stars – has to pass through Earth’s atmosphere, which bends and distorts the light, and there are other factors as well, such as: B. Vibrations in the telescopes. The result isn’t a clean single point-like image that can easily be recognized as a planet, but rather a series of speckles or noise. The trick is to refine the image processing technology so it can suppress the noise so astronomers can pinpoint the presence of an exoplanet.

The improved technology, which Singh is helping to develop, will allow astronomers to image smaller exoplanets that are less than 10 AU from their stars.

“The reason we can’t take pictures of Earth-like planets or… planets in our solar system is because getting rid of speckles is a challenge,” she said. “Speckles look like planetary signals, but they are not planetary signals. They are false positives…due to multiple factors including thermal distortion, temperature variation, misalignment. Even Earth’s atmospheric turbulence also introduces speckles and they basically obscure the planetary signals.”

Before coming to Canada, Singh worked as a postdoctoral fellow at NASA’s Jet Engine Laboratory in Pasadena, California and was a postdoctoral fellow on Marie Shlodowska-Curie Actions at the Observatoire de Paris-Meudon in France.

In November, Singh will move to Hawaii to work on 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, where she will discuss direct imaging techniques and the challenges they face. Visit www.nanaimoastronomy.com for more information.

[email protected]
Like us on Facebook and follow us Twitter

AstronomyResearchScienceSpace