Table of Contents
What is the temperature and brightness of a supergiant?
Supergiants have absolute visual magnitudes between -3 and -8. The temperature range of supergiant stars spans from around 3,450 K to 20,000 K. Supergiant stars can have masses from 10 to 70 times greater than our Sun, and when it comes to brightness, some of them can be from 30,000 times or brighter than our Sun.
What is the brightness of a red giant?
Red giant stars are between 100 to 1.000 times more luminous than our Sun.
What is the approximate temperature and luminosity of a super red giant?
The observed progenitors of type II-P supernovae all have temperatures between 3,500K and 4,400K and luminosities between 10,000 L ☉ and 300,000 L ☉.
How do temperature and luminosity change when a star becomes a red giant?
The core of a red giant is contracting, but the outer layers are expanding as a result of hydrogen fusion in a shell outside the core. The star gets larger, redder, and more luminous as it expands and cools.
What is the temperature of a red giant?
A red giant is a luminous giant star of low or intermediate mass (roughly 0.3–8 solar masses ( M ☉)) in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius large and the surface temperature around 5,000 K (4,700 °C; 8,500 °F) or lower.
What are giant and supergiant stars?
A giant star is a star with substantially larger radius and luminosity than a main-sequence (or dwarf) star of the same surface temperature. Stars still more luminous than giants are referred to as supergiants and hypergiants.
What temperature is Barnard’s star?
3,134 K
Barnard’s Star/Surface temperature
The effective temperature of Barnard’s star is found to be 3134 Ж 102 K; the precision of that result equals or surpasses that of the best temperature determinations for late-type dwarfs in detached, eclipsing binary systems.
What is the sun’s luminosity or brightness?
The rate at which photons carry away energy from the star is called the star’s luminosity. Luminosity is frequently measured in watts (that is, joules per second). However, since stars are so very luminous, it is more convenient to measure their luminosities in units of the Sun’s luminosity, 3.9 x 1026 watts.
What is the approximate luminosity of giant stars?
Giant stars have radii up to a few hundred times the Sun and luminosities between 10 and a few thousand times that of the Sun. Stars still more luminous than giants are referred to as supergiants and hypergiants.
What happens when a star turns into a red giant?
When hydrogen fuel at the centre of a star is exhausted, nuclear reactions will start move outwards into its atmosphere and burn the hydrogen that’s in a shell surrounding the core. As a result, the outside of the star starts to expand and cool, turning much redder.
Are red giant stars bright or dim?
Red giant stars have a cooler surface temperature which makes them redder in colour. Although cooler, the large size of a red giant makes it brighter overall. It can be thousands of times brighter than the Sun.