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Opening a hatch for solar systems

An overview of the way in which new planets outside the solar system are discovered, and what awaits us in the future thanks to new observation tools

 A planet outside the solar systemintroduction

For the past 10 years, groundbreaking research has been done in planetary astronomy. The reference is not to the stars around us, within the solar system in which we live, but to the planets orbiting other suns. To date, over 200 planets have been discovered and this is just the beginning. Most of the planets found, the scale for their size is Jupiter and this is due to technological constraints. The wet dream of the astronomers is to find planets the size of the Earth and this is for the reason that there are chances of finding life as we know it. It is not difficult to guess what the astronomical community will feel when technology is developed that will allow direct observation of these stars, similar to pointing a telescope from Earth towards Mars. The small amount of information that has already been revealed to researchers raises weighty questions about our solar system and in particular about those solar systems that are beginning to be revealed. The little information available to the astronomical community allows for a preliminary taxonomy.

Discovery methods

Today, three methods are accepted for discovering planets and they are discovery through vibration, discovery through gravitational settling and discovery through transit. The leading method and through which most of the new planets were discovered is the wobbling method. The working assumption underlying this method is that Jupiter-sized planets, even though they are tiny compared to the stars they orbit, still have an influence to the point of creating a vibration in their sun and as a result they pull it towards them to some extent and this vibration can be diagnosed using spectroscopic equipment. Due to their movement they create cycles in the vibration of their sun. When the vibration "approaches" the earth the effect is felt in a blue shift and when the vibration "moves away" the shift is felt in a red shift. From the duration of the cycle and the intensity of the vibration, it is possible to obtain basic data about the planet. If another periodic vibration is detected, it can be assumed that another planet has been discovered. This is actually a use of the Doppler effect known to every physicist and astronomer.

The second method is gravitational microlensing. This method refers to those cases where the magnetic field of a star behaves like lenses. It increases the light intensity of the star in the background. If the star that is close to the Earth (in relation to the star that is in the background) has a planet, then the gravitational field of the planet itself enhances the ability to magnify and from the differences between the magnification powers one can learn about the planet.

Another method for discovering planets is finding them between their sun and the earth, a phenomenon defined as a transit similar to the transit of Venus and Mercury. Since these are very large distances, light years, they dim the light of their sun. The differences between the intensity of the sun's light before the transit and during its occurrence and the periodicity of the phenomenon can give preliminary information about these planets.

Another method to think about is solar wind. For this we will accept as an assumption that these planets have magnetic fields and that also in their suns there is a phenomenon of solar wind. It is likely that there is an interaction between the solar wind and the magnetic fields of these planets similar to what happens in our solar system. Given very large planets (measured in Jupiter masses), their interaction will be greater for example than that between the magnetic field of Jupiter and the Sun. In optical telescopes it is difficult to follow this interaction, but it may be possible in infrared and/or ultraviolet. It may be that the visible product will be kind of flickering (fluctuating). The flashes will look like a lumpy pattern. If the planet is far enough from its sun, for example 5 astronomical units, it will be possible to notice its orbital motion and from this it will be possible to calculate its size and mass. With this method it is possible to distinguish several planets at the same time.

Taxonomy

So far we have been used to one solar system structure. Terrestrial planets near the Sun, asteroid belt, gaseous planets and Kupfer belt. The general convention was that the gaseous planets are always far from the Sun. And as soon as new planets began to be discovered, many of them received the name Hot Jupiters and for good reason, some of them are very close to their sun and due to their proximity, the temperatures on them are very high, hundreds of degrees Celsius. Due to their close proximity to their sun, their orbital period is very short and is measured in a few days, and in recent discoveries, some have been found whose orbital period is measured in hours. The planet SWEEPS-10 is at a distance of 1 km from its sun, orbits it once every 184 hours and its mass is 100 Jupiter masses (10. 1.6. 4 : "Hubble finds" web). The star Coranae Boralies has a planet with a mass of 10 Jupiter masses, its distance from it is 06 astronomical units and it orbits it once in 1 days. The star 1HD has a planet whose mass is at least 0 Jupiter masses, orbiting it once every 23 days and its distance from it is 39 astronomical units. The star 6 Gliese has a planet whose mass is 115019 Jupiter masses, which is 3 million km (4 astronomical units) away from it and orbits it once every 18 days.

Another kind of surprise is the invention of planets in binary systems. The planet can be found between the two suns when it orbits the inner sun, it can orbit the outer sun and it can orbit both suns as if they were one star. An example of a planet orbiting the inner Sun is the one in orbiting 195019 HD. The planet has 3 Jupiter masses, orbiting its sun once in 4. 18 days and his distance from her is 3. 0 astronomical units. The distance of the second sun is at least 14 astronomical units. A planet orbiting the outer sun is the one in the double star 150 HD. It is a brown dwarf that has 3651 Jupiter masses surrounded by a planet and both of them together orbit a star more or less the size of our sun. The planet itself is smaller than Saturn, the distance of the brown dwarf from the central sun is more than 50 times the distance of Pluto from the sun (10. 19. 9 : "Scientist find" web). A planet orbiting a binary system is the one orbiting the double star MACHO-06-BLG-91. The distance of the suns from each other is 41 astronomical units. The planet itself is 1 astronomical units away from them, even 8 Jupiter masses (7-3: 57 Bennett DP et al). Alongside these binary systems, an unusual system of 59 suns was discovered. A star about the size of our Sun in the 1999 HD system has a Jupiter-sized planet orbiting it once in 3. 188753 days and they both circle the other two suns (3. 5. 14 : "First Planet" web).

Among these large planets, there are some that stand out for their low density, which is to remind us of Saturn's density of 0. Examples of such planets are: the planet orbiting the star 69 HD, its distance from the Sun is 1897336 astronomical units, its diameter is 0.03 Jupiter diameters, its mass is 1.25 1 Jupiter masses, density 15, orbits its sun once every 0.75 days and its surface temperature is 2.219 °. Another planet is the one orbiting 844 HD. Its radius is 209548 Jupiter radii, its minimum mass is 1.3. 0 masses and its density 63. It orbits its sun once in 0.38 days, its distance from it is 3.523 astronomical units and its temperature is ?0 C.

A special planet is the one orbiting 179949 HD. . Such is the size of Jupiter, it orbits its sun once in 3. 09 years and causes the appearance of hot spots (Hot Spots) on her face. These spots move along the surface of the Sun parallel to the movement of the planet, except that they are a little ahead of it. According to the researchers, the explanation for this phenomenon lies in the powerful magnetic field of the planet that transfers energy to the sun. The energy creates bright spots that can be observed through telescopes (8. 1. 04 : "Discovery" web).

 

In terms of the geometry of the orbit, for most of the discovered planets, their orbital path is circular, but there are also some with great eccentricity. An example is the planet orbiting 168443 HD. Its mass is 5 Jupiter masses, it orbits its sun once in 58 days and the extreme points of its orbit are 0 and 45. 0 astronomical units. . Other planets are those whose distances from their sun are in earthly terms like the planet orbiting 15 Gliese. It is a star that has a mass of at least 614 Jupiter masses, its distance from the sun is 3 astronomical units and orbits it once in 3. 2 years in an almost circular orbit. Another planet is the one in Ursa Majoris 5, its mass is 4 Jupiter masses, its distance from its sun is 9 astronomical units, it orbits it once every 47 years and its surface temperature is C3 -.

 

Another group of planets is that of stars whose scale of measurement is the Earth. They are larger than the Earth but several orders of magnitude smaller than the gas giants and are defined as Super Earths.

876 Gliese is a moving planet that has a mass of 7 Earth masses, its radius is 5 Earth radii and its distance from its Sun is so small that it orbits once every two days. Another planet belonging to this group is a star whose mass is 2 Earth masses, its distance from its sun is 13 astronomical units and its surface temperature C? 2 - His sun is of the Red Dwarf type. The name given to this planet is 6-BLG-200LB (2005. 169. 13 : “Giant Earths” web ).

 

Over the years, solar systems with more than one planet were found, and let's not forget that additional planets may be discovered in those systems where one planet is already found. One of the interesting discoveries is the 1257+12 PSR pulsar with 4 planets (S. Stephens 1996:50-55). The first planet has 3 Earth masses, its distance from the Sun is 4 astronomical units and its orbital period is 0 days. The second planet has a mass of 36 Earth masses, its distance from the Sun is 66 astronomical units and its orbital period is 6 days. The orbits of these two planets are almost circular. A third planet has a mass about the mass of the Moon (2 Earth masses) and a distance of 8 astronomical units. It is possible that another planet is moving around this pulsar. Epsilon Andromeda has 0 planets. The nearest star to which it has a mass of 47 Jupiter masses, orbits it once in 98. 2 days, the second is 0 Jupiter masses and orbits it once in 015 days. The third, the most distant, has a mass of 0 Jupiter masses, its distance from the Sun is 19 astronomical units and orbits it once every 3 years. Caneri 0 has 75 planets. The first is at a distance of 4 astronomical units (6 million km), orbits it once every 2 days and the other planets orbit it once every 242 days, the third once every 4 and the fourth once every 3 years .

discussion

To use the customer nomenclature from the world of biological concepts, a zoo of different solar systems has been unfolded to the astronomical community both in terms of the types of suns and the types of planets. If we take for example the large stars whose mass is measured in Jupiter masses, regarding those closest to their sun, it is clear that they show only one side of their face (Mazar H. 2002: 15, 17), those among them that are 7, 8 astronomical units away from their sun, for example, revolve around their axis What is their axial velocity? Maybe their speed is also great. Jupiter, for example, rotates around its axis once every 10 hours, a speed of 45 km/h. The winds at the top of its atmosphere blow at hundreds of kilometers per hour. This high rotation speed causes the star to be flattened at its poles. This is what will happen in these stars as well. And the speed of Jupiter's rotation would have been greater, its obscurity would have been greater and the star would have taken on a somewhat elliptical shape. What are the dynamics of the winds on a large-mass planet compared to a spherical planet? The gaseous planets in our solar system emit more energy than they absorb from the sun. Does this process also occur in these planets? Do huge hurricanes of Jupiter's red spot-like dimensions also occur in these stars. The Galileo and Xexini spacecraft revealed previously unknown details about meteorological processes in the gaseous planets. Can this new information shed some light on similar processes in giant Jupiters?

Just as the gas giants in our solar system have moons, they likely have moons of their own. The largest moon in our solar system is Titan with a diameter of 5100 km. Due to the size of the Jupiter giants, they may have moons the size of Earth and they may also have atmospheres and possibly magnetic fields. In this case we will encounter a phenomenon that we have not encountered before. A terrestrial planet whose magnetic field interacts with the solar wind of its sun and the magnetic field of the planet it orbits. His day will be strange. If it is far enough from the planet it will rotate around its axis, during the day it will be exposed to sunlight and at night it will be exposed to the light coming from the surface of the planet which it surrounds due to the reflection of the light. It is illuminated throughout the day, but the intensity of the light changes cyclically. Strong sunlight during the day and weak light at night. The picture gets complicated when it regularly shows one side of its face to a planet like our moon. What are the consequences of a day like this on the weather? If there is life on it, what does it mean in terms of the biological clock. If it has flowing water or liquid methane like on Titan what will be the tidal patterns?

Regarding the terrestrial planets orbiting suns, there can be such as Earth and Mars and there can be giant earths (Giant Earthes). If their sun is smaller than the sun that the earth orbits, the intensity of the light will be weaker than what we know. What will be the difference in light intensity between day and night? What is their rate of rotation around themselves? What does this mean about heat transfer from the light hemisphere to the dark hemisphere? In case there is life on them, how will the weaker light intensity affect the structure of the pupil of the eye? To illustrate we will use a pictorial example. Let's suppose that on one of these planets the conditions are exactly the same as those prevailing on Earth except for the intensity of the sunlight, which is weaker by a factor of two and humans like us live on them. During their visit to our world, they will have to wear sunglasses at all times, otherwise they will not feel comfortable and also to prevent potential damage to the eyes. What does this mean about their worldview? A particularly extreme case is the same situation in which terrestrial planets have been found orbiting pulsars. For the sake of discussion, let's assume that life can exist on them. These worlds will be perpetually dim. Possible intermediate states are those cases where brown or red dwarfs are surrounded by their planets atmospheres. What color is their sky? It can be red, brown, purple. Pretty surreal pictures. Another case is of a planet orbiting an inner sun in a binary system or a sun orbiting a double star (the entire system is ternary). His day for most of the year will always be bright, except for that case when the planet and the sun will be in a straight line. Such a situation is described in Asimov's story "Sunset".

If these stars have several planets, in terms of their distances from each other, is there any legality according to Boda's Law, even if this legality is partial? How circular are their orbits? Let's not forget that planets with eccentric orbits have been found and this surely has far-reaching climatic effects. Are the stars tilted on their axis like the Earth? Are the planes of their orbits completely horizontal in relation to their plane of flight or are there anomalies in the form of Pluto's orbit?

Summary

The variety of questions is endless. It is possible to build worlds according to our good imagination and it is desirable to do a lot of these and thus gain insights into our own world as well. For those writers who deal with science fiction, a wide area for action opens up.

 Sources

Mazar H. - "The questions that arise following the discovery of new solar systems" Astronomy Volume 28 Issue 3 2002 p. 15, 17
Bennett DP et al- "Discovery of a planet orbiting a binary system from gravitational microlensing" Nature Vol. 402 4. 11. 1999

Stephens S. - "Second chance planets" Astronomy January 1996 pp 50-55

 

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