- 4597 - EXOPLANETS - planets outside our solar system? - By watching the Sun, astronomers are learning more about Exoplanets? We can detect the wobble of a star from the gravity of planets in orbit. Local variations in the stars can add noise to the data but researchers have been studying the Sun to help next-generation telescopes detect more Earth-like planets.
--------------------- 4597
- EXOPLANETS -
planets outside our solar system?
-
- To date 5,288 exoplanets have been
discovered in orbit around other star systems.
Before 1992 we had no evidence of other planetary systems around other
stars. Since then, and using various methods astronomers have detected more and
more of the alien worlds.
-
- Techniques to detect the exoplanets range
from monitoring starlight for tiny dips in brightness to studying the spectra
of stars. Just over 1,000 exoplanets have been discovered using the radial
technique making it one of the most successful methods.
-
- The local variations in the properties of
stars has made it difficult to find smaller planets using the radial technique
but a team of astronomers led by Eric B. Ford from the Department of Astronomy
and Astrophysics at the Penn State University has just published a report of
their findings following observations of the Sun. Observations of the Sun
between January 2021 and June 2024 using the NEID Solar spectrograph at the
WIYN Observatory have been used in their study.
-
- The planet, named “TOI-3757 b”, is the
fluffiest gas giant planet ever discovered around this type of star. Across the 3 years and 5 months of
observations, the team identified 117,600 features which are not likely to have
been caused by the weather, hardware or calibration issues so they could be
used for their study. Given that the distance between the Sun and Earth is
precisely known the team can use this to analyse solar observations and measure
other solar variability.
-
- Impressively the team have been able to show
that the NEID instrumentation is able to measure radial velocity of the Sun
accurate to 0.489 meters per second. Using this data the team conclude that
Scalpels algorithm (a technique developed for medicine that uses machine
learning to analyse and extract data from images) performs particularly well.
It can reduce the root mean square (used to analyse signal amplitude) of solar
radial velocity from over 2 m/s-1 down to 0.277 m/s-1!
-
- The results are significantly better than
previous studies at removing solar variability from its radial velocity
observations. This suggests that the next generation of exoplanet radial
velocity instruments are capable, at least technically at detecting
Earth-massed planets orbiting a star like the Sun. This does require sufficient
observing time which the team estimate would be about 103 nights of
observations.
-
November 3, 2024 EXOPLANETS -
planets outside our solar system? 4597
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--------------------- --- Tuesday, November 5,
2024
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