UCSB Science Line
Sponge Spicules Nerve Cells Galaxy Abalone Shell Nickel Succinate X-ray Lens Lupine
UCSB Science Line
How it Works
Ask a Question
Search Topics
Our Scientists
Science Links
Contact Information
What is the hottest star? Is there a hottest star in the universe or when a new one is born will it become the hottest star?
Answer 1:

There are thought to be more stars in the universe than there are grains of sand on all the beaches of the world combined. So, since we have only seen a small number of stars, we probably haven't found the hottest star. The hottest star we have found is called R136a1: hottest star . It has a temperature of around 72000 degrees Farenheit. The hottest stars are blue, as is this one. Stars are more hot when they die than when they are born. Some stars explode when they die (after billions of years). These explosions are called supernovas or hypernovas, and may be well over 100,000,000,000 degrees.

Answer 2:

The hottest surface temperature for a star would be that of a star in the process of going supernova. Supernovae last a few weeks.

Answer 3:

This is an excellent question, as it is difficult to pin down the hottest temperature. When astronomers talk about the temperature of a star, they are referring to the temperature of its surface. They can calculate its surface temperature from the colors that it emits. A yellow sun like ours has a surface temperature of ~5500°C. The brightest and hottest stable star we have seen so far is a blue-colored supergiant called HD 93129A, with a surface temperature of ~48,000°C. This star is 2.6 million times brighter and it’s radius is 25 times larger than our sun. Blue supergiants are very rare and burn through their stores of hydrogen quickly.

While this is very hot, stars are even hotter at their center. Even our sun has a core temperature of about 15 million degrees. (That’s 15,000,000°C.) Stars are the hottest when become supernova, where the explosion of radiation can reach temperatures of 100 million degrees (100,000,000,000°C). The hottest spot we’ve observed in the universe was estimated at 300 million degrees where multiple galaxies collided. (Check out: hottest spot in the universe )

Scientists estimate that the “Big Bang” explosion that created the universe was up to 10x hotter than that. That’s really hot!

Surprisingly, the hottest point in the universe recently may be man-made by scientists at Brookhaven National Lab. They collided particles at very high speeds to simulate the beginning of the universe and achieved temperatures greater than 4 trillion degrees! (4,000,000,000,000°C) (Check out: hottest temperature measured )

Click Here to return to the search form.

University of California, Santa Barbara Materials Research Laboratory National Science Foundation
This program is co-sponsored by the National Science Foundation and UCSB School-University Partnerships
Copyright © 2015 The Regents of the University of California,
All Rights Reserved.
UCSB Terms of Use