????Learn Astronomy in the largest Astronomy Course in Brazil: https://academyspace.com.br/bigbang WATCH NED'S VIDEO: • EXOPLANET PROXIMA b MAY HAVE A COMP... ------------------------------------------------------------------------------------------------------------ VISIT THE SPACETODAY STORE: https://www.spacetodaystore.com ------------------------------------------------------------------------------------------------------------ BECOME A MEMBER OF SPACE TODAY AND HELP WITH THE CREATION OF SERIOUS CONTENT IN THE AREA OF ASTRONOMY: / spacetoday https://apoia.se/spacetoday / @spacetoday -------------------------------------------------------------------------------------------- LISTEN TO THE EVENTS HORIZON PODCAST - TODAY'S EPISODE - BETELGEUSE / horizonte-de-eventos-episodio-7-betelgeuse... ------------------------------------------------------------------------------------------------------------ COME PARTICIPATE IN THE COURSE SPACE TODAY ASTRONOMY: http://academyspace.com.br/bigbang ----------------------------------------------------------------------------------------------- How far away is the star Betelgeuse? Well, it seems like an easy answer to give, doesn't it, since everyone talks about the star today. But it's not. It was only about 30 years ago, with the use of new technologies, that astronomers were able to make relatively more precise measurements of the size of Betelgeuse. This began in 1989, when the ESA's Hipparcos satellite was launched. Its mission was to precisely measure the distance, position and movement of stars in the Milky Way. It managed to do this by measuring about 100,000 relatively close stars. The mission was named after the Greek astronomer Hiparchus, who did some of the first work in astrometry, that is, measuring the position of stars in the sky. The mission used the famous parallax to measure the distance to the star. Quite simply, you observe a star in the sky at a point in Earth's orbit. Six months later, you observe the same star and calculate how much it has moved in relation to the background. Using basic trigonometry, you can calculate the distance to the star. This is one way to measure distances in the universe and is valid for these closer stars. For objects further away, the angle becomes impossible to measure and this technique needs to be replaced by others. Well, the original measurement made by Hipparchus was 7.63 milliarcseconds, which gives a distance of 430 light years. However, Betelgeuse is a variable star; its brightness changes and this variation makes it very difficult to measure the distance to the star. Astronomers then began to find errors in the measurements made by Hipparchus for variable stars. In an attempt to correct these errors, new measurements were made, and this time, the calculated angle was 5.07 milliarcseconds, which gave a distance of 643 light-years to Betelgeuse, with an error of plus or minus 46 light-years. In an attempt to further improve the estimate of the distance to the star, astronomers then decided to use the Hipparcos mission together with measurements made with radio telescopes. This would minimize the errors in the measurements due to the star's variation. With this, astronomers arrived at the distance measurement of 724 light-years, the measurement that is used and so much talked about today. In fact, the distance to the star is between 613 and 881 light-years, including the uncertainty in the data. Then, someone might ask, why not use the Gaia mission, which is much more modern and much more accurate in its measurements. The reason is that Betelgeuse is very bright and relatively close, and this ends up saturating the probe's sensors, which would actually result in less accurate measurements. So note that Betelgeuse is 724 light-years away from Earth, which means that if it exploded, it was in 1295, and if it explodes today we will only know in 2743. Source: https://earthsky.org/astronomy-essent... https://arxiv.org/pdf/1706.06020.pdf #Betelgeuse #Distance #SpaceToday