Wednesday , October 5 2022

Astronomer of the Persians and Comets


Celestial theaters have been fascinating for centuries, and testimonies are also given by scientists Galileo Galilei, Isaac Newton and Johannes Kepler. Slovak astronomer Ján Svoreň of the Astronomical Institute of the Slovak Academy of Sciences in Tatranská Lomnica fell in love with the sky and became their popularizer. answered questions about not only falling stars known as the Persians, but also about our sky and meteor showers in the sky.

How do bugs and falling stars form?

The meteor particles that we see glowing in our atmosphere, people falling stars, are tiny grains of dust weighing up to several grams. The fact that they produce such a powerful spark that looks like a star has fallen is caused by an enormous velocity of up to several tens of kilometers per second that collides with the air molecules. These dust grains have their origin in comets. Comets consist of ice (mainly water but also other frozen gases) and about 20% dust. Approaching the Sun, the ice sublimates, pulling with it dust particles from the comet core, which then move through space near the comet orbit until they collide with our atmosphere.

Probably the most anxious about the famous Persians, who are supposed to have their summit on 11-12 August 2019. How do they see them so clearly and there are many?

It is an annual recurring theater – a meeting of Earth with a stream of dust particles in the orbit of a periodic comet 109P / Swift-Tuttle (the comet orbit period is 133 years). Meteors move out of the atmosphere in parallel orbits similar to a comet orbit and, when they enter the Earth's atmosphere, burn at altitudes over 80 kilometers. Looking at them from Earth, from a perspective, they seem to fly from one place in the sky, which is located in the constellation of Persia, hence the Persian name.

Most of the particles are parts of the cloud thousands or more ago. The swarm is observed annually with approximately the same maximum frequency of 45 to 60 meteors per hour. It runs from the last decade of July to mid-August, with individual meteors occurring until mid-September. The current is about 65 million kilometers. The central fiber is relatively narrow (about 10 million kilometers) – in 4 days around the maximum 62% of all Persians encounter Earth.

Lately we have been seeing cold water from the South Delta. Is it normal that we can also see them from our territory?

It is visible every year from 14 July to 3 September with a maximum of 29 July. His mother's body, a comet, is unknown. The Delta Aquarids orbit resulting from photographic observations has an extremely low perihelion distance (the closest point of the orbit to the Sun), just 0.09 from the astronomical unit. Geocentric speed Delta Aquaríd is 41 km / s, belongs to a moderately fast swarm. The first records of Delta Aquarid observations are dated July 19, 714.

Looking at the sky over Slovakia, what constellations can we observe?

As the Earth rotates, the sky above us seems to rotate. Other stars in the evening are in the sky, differently in the morning. And because of the Earth's orbits around the Sun, almost all constellations change gradually over the course of the year. From Slovakia we can only see the constellations of the southern sky located near the south pole. On the other side are constellations of the northern sky. Circumculars close to the Polaris we can still see, such as the Big Bear, the Little Bear, the Dragon, the Giraffe, the Cepheus, and the Cassiopeia.

Slovakia is a relatively small country. Is the sky above it specific, exceptional?

No, because of the rotation of the sky, all places on the globe on a given parallel (Slovakia is about 48 to 49.5 degrees north latitude) can see the same part of the sky, of course at different times. For example, in Paris, they will see exactly what we, just an hour later.

If one wants to watch stars in his spare time, how is he prepared?

Of course this depends on how much money he wants and can give his hobby. Someone needs to be informed – in this case we recommend the popular scientific journal Kozmos, where information on all the hot news will appear. There are great websites on the internet, just be careful not to confuse some "experts" who are spreading their theories through this medium that no one else recognizes. If we not only want to hear about the universe, but also see something, we have 2 options.

The first, less expensive, is to contact some educational facilities in the area. Most observatories operate astronomical clubs, where the interested person can also observe interesting phenomena such as observing meteors, plotting sunspots, monitoring long-term changing stars and so on. The hardest way, but also bringing the most experience, is to get your own astronomical telescope and look at the universe from your own garden or balcony. Combined with a good digital camera, you can get your own images of space and present yourself on the internet.

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