The new video shared on YouTube is one of the most amazing things we’ve ever seen in planetary science.
The video shows four points of light moving in partial concentric circles around the centerpiece of the gramophone record. What you actually see are planetary systems.
These four points are exoplanets, with a black disk covering their star, 133.3 light years from Earth. The partial circle is its orbital motion, the time interval of which is composed of 12 years of observations.
The star is HR8799 in 2008 The exoplanet forms the first system (not the first exoplanet 2M1207b in 2004) astronomers have never seen one directly.
Since then, astronomer Jason Wang of Northwestern University has been watching it with great interest. He grouped these observations into time intervals — not for any scientific reason, but simply because they were so interesting.
“Usually it’s hard to see planets in orbit,” said Wang.
For example, it is not clear Jupiter or Mars It orbits our sun because we live in the same system and we don’t have a top-down view. Astronomical events occur too fast or too slow to capture on film.
“But this video shows the planets moving on human timescales. I hope it allows people to enjoy something amazing.”
The current number of Confirmed exoplanet – This is an exoplanet, or exoplanet – number more than 5,200But we haven’t really seen most of them yet.
Astronomers mainly find exoplanets through the indirect method, by studying the influence of an exoplanet on its parent star. A faint flicker in starlight indicates the presence of an exoplanet orbiting between us and the star; Faint changes in the wavelengths of starlight indicate gravitational interactions between the exoplanet and the star.
The reason is that it is actually very difficult to see exoplanets directly. It is very small and very dim compared to its parent star; Any light that it emits or reflects is usually swallowed up by the shining starlight.
Sometimes, we get lucky. The exoplanet is quite large and separate from its star, and its system is oriented in such a way that, if the star’s light is blocked or obscured (which is why HR8799 appears as a black disk), we can see it as a small companion point. Noor.
It’s even rarer to see them carry out complex planetary alignments, simply because the orbital timescales involved are much longer than the time since scientists directly discovered the first exoplanet.
But Wang and his team now have enough observational data for HR8799 to show a partial orbit time lapse, and this is what they have collected.
“There’s nothing scientific to gain from watching tropical systems in time-lapse videos, but it helps others to appreciate what we learn.” said Wang.
“It’s hard to explain the nuances of science in words. But demonstrating science in action helps others understand its importance.”
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The observations were collected using the WM Keck Observatory, and Wang applied adaptive optics to correct for the distorting effects of Earth’s atmosphere.
Time-lapse is also processed to correct for time jumps between the data, which show smooth orbital motion of the four outer planets.
12 years of observation sped up by just 4.5 seconds.
This is what you’ve been looking for. The black circle in the center is a 30 million year old star, more than 1.5 times as massive, and 4.9 times brighter than the Sun.
The innermost outer planet is HR8799e, with a mass of 7.4 planets orbiting at a distance of 16.25 times the Earth-Sun distance, or astronomical units, with an orbital period of 45 years. Scientists can analyze the light from this exoplanet to determine if storm Gas giant child.
Moving outwards, HR8799d has a mass of 9.1 Jupiters, and orbits at 26.67 AU with an orbital period of 100 years.
HR8799c has a mass of 7.8 Jupiters, and orbits at a distance of 41.4 AU (slightly greater than the distance between the Sun and Pluto) with an orbital period of 190 years. she has water in the atmosphere, Scientists found.
Finally, HR8799b has clocks on 5.7 planets, with a separation of 71.6 astronomical units and an orbital period of 460 years.
But we are still far from working with the HR8799 system.
While, according to Wang, the interval itself may not be a scientific discovery, the Keck dataset is.
The paper was published in December last year It found a possible fifth exoplanet, smaller and closer to the star than its sibling. The candidate’s mass is estimated to be about 4 to 7 times that of Jupiter, and it orbits at a distance of between 4 and 5 AU, making it difficult to identify directly.
Wang and colleagues have been working hard to analyze the light from the system. They hope to obtain detailed information about the composition of not only stars, but also the world around them.
“In astrophysics, most of the time we are analyzing data or testing hypotheses,” said Wang.
“But that’s the fun part of science. It inspires awe.”
