“Planetary Construction Area Found Around Young Star TW Hydrae”

Astronomers have found evidence of a planetary construction area around the young star TW Hydrae (TW HYa), which is 200 light years from Earth.

TW Hydrae

TW Hydrae, young star T Tauri in the constellation Hydrae or this snake is still young. It is only about 10 million years old and 60% the mass of the Sun. The star TW Hydrae is a red dwarf star that recently formed. And of course around it there are still remnants of gas and dust that form the disk that surrounds this star. This disk of gas and dust is the construction area or the area where planets should form around the young star.

Inevitably, TW Hydrae is a laboratory for astronomers to study the formation of planets and their evolution. Moreover, the distance is also not too far from Earth. Only 200 light years!

In previous observations, astronomers found indications exoplanet that is forming around this star. Among them is the unconfirmed planet TW Hydrae b, as well as a planetary candidate that is equivalent to Pluto’s distance from the Sun in the TW Hydrae system.

Shadow in the Ring

Several years ago, astronomers also detected shadows sweeping over matter in the area protoplanetary disk. Like the hands of a clock moving around the clock. At the time it was discovered, astronomers suspected it was the action of a thick inner disk that was moving around the star.

Apparently, observations with the Hubble Telescope actually found a second shadow. This discovery makes the gas and dust disk aka protoplanetary disk in TW Hydrae look complicated because there are three disks with two tilted disks.

Astronomers also suspect that there is an invisible planet orbiting the star. As a result, the gravity of the planets actually pulls matter and bends the disc of gas and dust that was flat like a pancake if there were no planets there.

In the Solar System, the planes of the planets’ orbits also vary in tilt of about a few degrees with respect to each other. Because of that, what happened in TW Hydrae can be a clue to what happened when the planets in the Solar System formed 4.6 billion years ago.

The second shadow is found in the 2021 observational data to predict the position of the planet which is indicated to cause the tilt of the disk. When this new image was compared with old observational data from the Hubble Telescope, astronomers found that the two misaligned disks cast an image. Previously, astronomers could not separate the two disks because they are very close. Over time, these two disks are increasingly separated and divided into two shadows.

What appears on TW Hydrae has never been found in the protoplanetary disks of other stars. And this makes the process of forming planets in TW Hydrae’s protoplanetary disk even more complex.

Planet di TW Hydrae

From the results of observations showing that the two protoplanetary disks are at a close distance, it can be concluded that there are two planets that are very close. If one of the planets was moving faster then astronomers should be able to know its existence. It’s like two racing cars that are close together and then one of the cars slowly overtakes the other car.

The candidate for the suspected planet is estimated to be at Jupiter’s distance from the Sun and its shadow takes 15 years to orbit the star. It is tilted about 5-7 degrees to the plane of the outer disk. The system’s largest disk has a gap at twice Pluto’s average distance from the Sun, indicative of the third planet in the TW Hydrae system.

For inner planets it is still difficult to detect because the extraordinarily bright starlight has covered this planet. It’s like we can’t see stars during the day because they are in the light of the sun. Not only that, the dust in the TW Hydrae system also has the potential to dim the planet’s light. One way to find inner planets in TW Hydrae is the radial velocity method if the planets are big enough.

If there is an inner planet the size of Jupiter, then its gravitational interaction with the star can cause the star to wobble. Observations of this radial velocity can be made by ESA’s Gaia satellite. In addition, JWST’s sharp infrared eyes can also penetrate dust and see these shadows in greater detail.

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