The North Star is bigger than we thought. Much bigger.

Polaris or the North Star is a star that can be seen with the naked eye, and is located closest to the celestial pole. If we can identify it in a clear night sky, we can orient ourselves in the cardinal directions. All we have to do is face the North Star and we know that we are facing north.

So it should come as no surprise that scientists have been observing this star for a long time, trying to learn as much as possible about it. And as it turns out, after hundreds of years of research, we can still learn something new about it. In the latest scientific paper published so far on the scientific preprint server, a team of scientists reports that the star is actually much older than previously thought. This in turn means that we also need to make a correction to our estimates of the star’s age.

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Until now, scientists assumed that the mass of the pole star was 3.45 solar masses. But now scientists are surprised They mentionedThe star is much larger and has an actual mass of 5.1 solar masses.

It is worth emphasizing here that the star’s mass was determined as a result of analyzing the motion of a much smaller and fainter star orbiting the Pole Star. Interestingly, this star was discovered only in 2005.

The large discrepancy between previous and current estimates of Polaris’ mass requires a change in the approach to estimating a star’s age. As a general rule, the more massive a star is, the shorter its lifetime. Suffice it to say that the smallest stars, red dwarfs, can live for trillions of years. Larger stars like the Sun can exhaust their fuel in about 10-12 billion years. However, the largest and most massive stars end their lives after only a few million years. The range of lifetimes is therefore truly large and directly depends on the star’s mass.

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Previously, the age of Polaris was estimated to be about 100 million years. However, if this star now turns out to be much more massive than previously thought, it must be assumed that it reached its current stage of evolution much faster, and is therefore actually younger than 100 million years.

The star orbiting Polaris, which is invisible at first glance, takes about thirty years to complete one orbit around its companion. So, since the star was discovered in 2003, we have had observations of its motion over most of its orbit, which we can use to measure the mass of the system. Obviously, it can’t be done any faster.

Astronomers are particularly interested in knowing the mass of Polaris, which is 447 light years away, because it will allow us to improve models of a very important class of stars, called Cepheids, which are regularly used to measure distances in the universe. Although we know of a fair number of Cepheids, only a few have been determined to have masses.