[ad_1]
Beta Pictoris' family seems bigger than we thought: there is good evidence of a possible second giant planet orbiting the near star.
This is important and cool for a lot of reasons. To understand this, one must look at the star itself.
Beta Pic (as connoisseurs know) is quite close to us, about 65 light-years away from us. This distance makes studying easier compared to most other stars. it's brilliant (the "Beta" of its name is a deadly gift: it's the second brightest star in the Pictor constellation) and we have a better view of what's going on around it.
It's also very young. Age is estimated at 23 million years, making it a baby. This too is interesting because in the 1980s it was found that it emitted too much infrared light for a star of its age and mass. This excess infrared, as it is called, has been postulated as being due to a lot of dust around it, and enough detailed images have now shown only to have a record, but that It is almost oriented like a line going through the star. This disk is that from which the star was formed, and from which planets are formed!
It was a state-of-the-art observation for the time, but we continue to improve, and soon this record has been mapped in a much more detailed way, and on the inside (it is about 7.5 to 15 billion kilometers from the star). was found to be deformed. This could be due to the presence of a giant planet in a slightly inclined orbit, it was thought, pulling on the inner edge with its gravity.
And of course, in 2008, astronomers announced they found the exoplanet! Called Beta Pic b, it revolves around the star at about 1.5 billion kilometers (comparable to Saturn's orbit around the Sun). My favorite part, though, is that it was discovered by direct imaging: it was physically seen in pictures! And over time, he was also seen moving into orbit around the star. Impressive.
In addition, there is fairly convincing evidence of exocometes (the name of comets orbiting another star) around the star. As they fall inward, the comet material vaporizes, wraps around them, and then absorbs the star's light at specific wavelengths.
It is therefore a complex system, emblematic in its diversity and our ability to study it. Every new discovery on this subject is important.
For example, find a second giant planet.
The planet is called Beta Pic c, and if the astronomers who study it are correct, it has revealed its presence through its gravity. When it revolves around the star, the planet shoots it, thus making it make a small circle as the planet makes it a big one (this is called reflex movement). ). Seeing this move is incredibly difficult (although not impossible, I'll explain it in a second), but this movement causes a Doppler shift in its light: when the star rocks toward us, its light is shifted slightly to the blue and when it rocks the light is redshifted.
Astronomers observe an impressive 6,645 spectra taken in 14 years (!!) to measure this periodic shift. It was not easy. The star itself palpitates physically, becomes larger and larger over time, and exhibits more complex movements in the upper atmosphere that also interfere with the measurement of this Doppler shift. But as many spectra mean that they could really draw from it, and when they made a change with a period of about 1,200 days, the orbital period of Beta Pic c.
The best fit to their data is a planet with a mass of 8.9 times that of Jupiter (which makes it a gas giant) circling the star on an elliptical trajectory at about 400 million kilometers. This places it well in the orbit of Beta Pic b, but of comparable mass (b has a mass of about 10 times that of Jupiter).
This has many implications on which it is fun to think. On the one hand, it is the very first time that two planets are discovered in a system where one was discovered by direct imaging and the other by the reflex velocity method. On the other hand, this makes the Beta Peak planetary system one of the best known; Only two other known exoplanetary systems have a higher combined mass.
It is possible, thanks to the elliptical orbit, that at the maximum distance of the star, Beta Pic c is even directly observable, although it is a difficult observation to make. As I have already mentioned, the actual motion of the star moving due to the severity of C is even harder to detect … almost. The authors note that it may be detectable in the Gaia Space Observatory data when it releases another important publication in a few years. During this period, movement in the star can be observed. Whoa.
They note that it is even possible that Beta Pic c passes the star, passing directly in front of her when she orbits, attenuating the star. This seems unlikely, in my opinion, as it would have been done many times since we started to really look at the star, and nothing has been seen. However, it is also quite possible that we just missed it. it is difficult to observe a star often enough to be able to observe each transit. They note that if the planet has large objects sharing its orbit (what we call Trojan objects), they could also transit. This is definitely an interesting thing to look for.
In addition, the disk around the star has strange holes and knots, which suggests that there may be even more planets further away, perhaps 3 billion kilometers away. Clearly, we are far from having finished finding treasure around this young star. And each time we do, we learn more about the birth of stars, the birth of planets, and how planets are born. systems were born. And that's why we keep looking.
[ad_2]
Source link