Which stars are bigger blue or red?

Which stars are bigger blue or red?

Apart from the temperature and brightness, the colour also usually —with the same qualification— indicates the size of a star: the hottest and most energetic blue stars are usually bigger and the red ones smaller.

What is the biggest supergiant?

VY Canis Majoris
The largest known red supergiant is thought to be VY Canis Majoris, measuring about 1800 times the size of the Sun. Imagine if the Sun extended out to the orbit of Saturn.

How big is a blue supergiant star?

Blue supergiants are hot, luminous stars. Red supergiants are the largest stars and can be between 200 and 800 times the radius of the sun, while blue supergiants are much smaller, usually less than 25 times the sun’s radius.

Why are blue supergiants smaller than red supergiants?

Blue giant stars are very hot, with surface temperatures of 20,000-50,000 Kelvin. Blue supergiants can turn into red supergiants and vice versa. When the star is smaller and more compact, its luminosity is contained over a smaller surface area and so its temperature is much hotter; this is the blue supergiant phase.

Why are blue supergiants blue?

These stars have surface temperatures of between 20,000 – 50,000°C and appear blue in colour. They are termed ‘blue supergiants’ due to their appearance and the enormous amounts of energy that they can radiate. So much energy is created in the centres of these stars that they are always on the edge of catastrophe.

How big is a red supergiant?

Red supergiants have masses between about 10 M ☉ and 40 M ☉. Main-sequence stars more massive than about 40 M ☉ do not expand and cool to become red supergiants. Red supergiants at the upper end of the possible mass and luminosity range are the largest known.

What color is a red supergiant?

Red supergiants look red because of their low surface temperatures. They range from about 3,500 – 4,500 Kelvin. According to Wien’s law, the color at which a star radiates most strongly is directly related to its surface temperature.

Why are blue giants smaller than red giants?

In astronomy, a blue giant is a hot star with a luminosity class of III (giant) or II (bright giant). They are much rarer than red giants, because they only develop from more massive and less common stars, and because they have short lives in the blue giant stage.

Which stars are blue supergiants?

Blue supergiants are supergiant stars (class I) of spectral type O. They are extremely hot and bright, with surface temperatures of between 20,000 – 50,000 degrees Celsius. The best known example is Rigel, the brightest star in the constellation of Orion.

What color are supergiants?

Red supergiants have the largest radius of all known stars. They have low surface temperatures (for stars!) of below 4,100 K. This causes them to shine with a red colour. The star Betelgeuse in the constellation of Orion is a red supergiant.

What color are red supergiants?

How much bigger are red supergiants?

In general, however, red supergiants have radii approximately 1,500 times larger than the radius of our sun. The largest of the supergiants are called hypergiants. The largest such hypergiant is VY Canis Majoris, which has a radius 1800 times larger than our sun’s.

What is the difference between a red giant and a hypergiant?

The term hypergiant stars describe a star’s luminosity rather than its physical size, so blue hypergiants can actually be smaller than the standard red giants formed by normal Sun-like stars towards the end of their lives, despite being many times brighter. Rare red hypergiants, however, are the biggest stars in the universe.

What is the luminosity of a blue hypergiant star?

Because yellow hypergiants are post-red supergiant stars, there is a fairly hard upper limit to their luminosity at around 500,000–750,000 L☉, but blue hypergiants can be much more luminous, sometimes several million L☉.

What is the most massive supergiant star?

The most massive of supergiant stars are known as hypergiants. However, these stars have a very loose definition, they are usually just red (or sometimes blue) supergiant stars that are the highest order: the most massive and the largest.

Which stars are not considered hypergiants?

Wolf Rayet stars, slash stars, cool slash stars (aka WN10/11), Ofpe, Of +, and Of * stars are not considered hypergiants. Although they are luminous and often have strong emission lines, they have characteristic spectra of their own.