The hottest star ever found

A white dwarf on the edge of our galaxy has been spotted that reaches record-breaking temperatures of 250,000°C (450,000°F).

This makes the star, known as RX J0439.8-6809, 42 times hotter than our own sun and 50,000°C (90,032°F) hotter than any star previously found.

THE HOTTEST STAR IN THE GALAXY

RX J0439.8-6809, is a white dwarf about five times as massive as our Sun.

Recording a temperature of 250,000 degrees Celsius, it smashes the previous record of 200,000 degrees – even though it is already cooling down.

Amazingly, the star would have been as hot as 400,000 degrees just 1,000 years ago – the blink of an eye in astronomical terms.

When RX J0439.8-6809 was first discovered more than 20 years ago, it was so bright it was thought to be part of the Large Magellanic Cloud – a small galaxy orbiting the Milky Way.

The new Hubble data show that the star is actually on the outskirts of the Milky Way, moving away at a speed of 220 kilometers per second – or 490,000mph.

By comparison, our sun is cool at just under 6,000°C (10,832°F), and has been relatively stable at that temperature for 4.6 billion years.

When it begins to burn out, in about another 5 billion years, it will reach 180,000°C (32,4032°F) – still hot enough to vaporise the inner planets including Earth.

Stars heat up as they reach the end of their lives, having used up most of the nuclear fuel at their cores.

It was previously thought the hottest stars were dying blue hypergiants, with masses more than 100 times our sun.

To find such high temperatures in a relatively small white dwarf might change how astronomers rank such stars.

The new Hubble data, however, proves that the star is actually on the outskirts of the Milky Way, moving away from us at a speed of 490,000mph – or 220 kilometres per second .

Source: Daily mail

N.H.Kh