A week ago we tried to understand how many stars there are in the Universe, a question that is really complicated to answer but on which researchers are always active in search of an increasingly reliable number. But what is the hottest star in the universe? There is an answer to this question, and it is quite rare.
The star we’re talking about is WR 102, WO2 class Wolf-Rayet star about 9,400 light years away from the solar system. Let’s immediately clarify two points: a star of Wolf-Rayet (or W.R. star, from which the name) is a massive star, often eruptive, very evolved and very warm compared to the average, its color is white- It means that in its own spectrum it has the lines of ionized oxygen four or five times: it is something extremely rare, so much so that up to now only three other stars are belonging to this class Â always stopping at
In the specific case of WR 102, it has a temperature of 210,000 K, brightness equal to 282,000 times that of the Sun, is small but really dense. You think that its outer layers are ejected at a speed of about 5,000 km/s, thus generating a star wind that makes it lose a mass of about 10-5 solar masses each year. According to current calculations, this WR star will explode in a supernova within the next 1,500 years and is believed to give rise to a gamma flash.
It is interesting to note, finally, that the other two hottest stars we discovered are Wolf-Rayet stars and belong to the WO2 class: both WR 142 and LMC195-1, have a temperature of 200,000 K.
To satisfy your curiosity a little more, here is the smallest star in the Universe.