(ORDO NEWS) — The new video posted on YouTube is one of the most amazing things we’ve ever seen in planetary science.
The video shows four dots of light moving in partially concentric circles around a black disk towards the center. You are actually seeing a planetary system.
The Four Dots are exoplanets with a black disk covering their star, 133.3 light-years from Earth. The partial circles are their orbital movements, a time interval made up of 12 years of observations.
The star HR8799, and in 2008 its exoplanets made up the first system (not the first exoplanet, it was 2M1207b). in 2004) astronomers have ever seen it directly.
Since then, astronomer Jason Wang of Northwestern University has been watching him avidly. He combined these observations into slow motion – not for any scientific reason, but simply because it is very cool.
“It’s usually hard to see planets in orbit,” says Wang.
“For example, it is not obvious that Jupiter or Mars revolves around our Sun, because we live in the same system and do not see from top to bottom. Astronomical events either happen too fast or too slow to be captured on film.
“But this video shows the movement of the planets on a human time scale. I hope this will allow people to enjoy something amazing.”
The current number of confirmed exoplanets extrasolar planets or planets outside the solar system is over 5,200, but we’ve never seen most of them.
Astronomers mostly find exoplanets indirectly by studying the exoplanet’s influence on its parent star.
Regular faint dips in starlight indicate that an orbiting exoplanet is passing between us and the star; the wavelength of a star’s light indicates the gravitational interaction between the exoplanet and the star.
The reason for this is that it is actually extremely difficult to see an exoplanet directly. They are very small and very faint compared to their host star; any light they emit or reflect is usually absorbed by the star’s bright light.
However, we get lucky from time to time. Exoplanets are large and fairly distant from their star, and the system is oriented so that if the star’s light is blocked or obscured (so HR8799 looks like a black disk), we can see them as small blobs of accompanying light.
It is even rarer to see them perform their complex planetary pavane, simply because the timescales of the orbits involved are much longer than the time that has passed since scientists directly observed the first exoplanet.
But Wang and his team now have enough observational data on HR8799 for a time-lapse showing partial orbits, and that’s what he’s collected.
“There is nothing scientific about viewing orbital systems in time-lapse video, but it helps others appreciate what we are studying,” says Wang.
“It can be difficult to explain the nuances of science in words. But demonstrating science in action helps others understand its importance.”
The observations were collected using the W. M. Keck Observatory, and Wang applied adaptive optics to correct for the distorting effect of the earth’s atmosphere.
>The time-lapse footage has also been processed to correct for time jumps between data, showing the smooth orbital movement of the four exoplanets.
12 years of observations were reduced to 4.5 seconds.
That’s what you’re looking at. The black circle in the center is a young star, 30 million years old, about 1.5 times as massive and 4.9 times as bright as the Sun.
The innermost exoplanet is HR8799e with a mass of 7.4 Jupiter masses, orbiting at a distance of 16.25 times the distance between the Earth and the Sun, or astronomical units, during an orbital period of 45 years.
Scientists were able to analyze the light from this exoplanet to determine that it was a child gas giant affected by the storm.
Moving outward, HR8799d has a mass of 9.1 Jupiters and an orbit of 26.67 astronomical units over a 100-year orbital period.
HR8799c has a mass of 7.8 Jupiters, orbiting at a distance of 41.4 astronomical units (slightly wider than the distance between the Sun and Pluto) over a period of 190 years. Scientists have discovered that there is water in its atmosphere.
Finally, HR8799b is 5.7 Jupiters away, with a distance of 71.6 astronomical units and a period of 460 years.
But we are far from finished with the HR8799 system.
While the timelapse itself may not be scientifically revealing, according to Wang, Keck’s data collection certainly is.
A paper published last December found the possible existence of a fifth exoplanet, smaller and closer to a star than its siblings.
The candidate is estimated to be about 4 to 7 times the mass of Jupiter and orbits at a distance of 4 to 5 astronomical units, making it difficult to detect directly.
And Wang and his colleagues are working hard. analysis of light from the system. They hope that they will be able to obtain detailed information about the composition of not only the star, but also the worlds surrounding it.
“In astrophysics, most of the time we do data analysis or hypothesis testing,” says Wang.
“But this is the most interesting part of science. She inspires awe.”
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