We define the subscripted symbol to mean that of the Sun. Thus the Sun has a
luminosity of 1 L (1 L = 3.9 × 10 ergs per second), and a temperature of 1 T (1 T = 5,800 K)
. Ori could radiate more total energy – it must have a larger total surface area.
What is the luminosity of our sun?
luminosity, in astronomy, the amount of light emitted by an object in a unit of time. The luminosity of the Sun is
3.846 × 10
26
watts
(or 3.846 × 10
33
ergs per second).
” The Luminosity of
a star is proportional to its Effective Temperature to the 4
th
power and its Radius squared
.” Example 1: Two stars are the same size, (R
A
=R
B
), but star A is 2x hotter than star B (T
A
=2T
B
): … In words: “If two stars have the same effective temperature, the larger star is brighter.”
How does temperature affect a star’s luminosity?
Luminosity Is Caused By…
That increased surface area allows more light and energy to be given off. Temperature also affects a star’s luminosity. … As a star gets
hotter
, the number of nuclear reactions increases. More reactions, more energy.
What is the temperature of sun Corona?
However, what intrigues astronomers is the fact that this outermost layer is much hotter compared to the surface of the Sun, where fission reaction is fuelling the star. The corona emits ultraviolet, X-rays and consists of ionised gas at temperatures
exceeding 2 million degrees Fahrenheit
.
What is the temperature of each layer of the Sun?
The centre of the Sun:
about 15 million kelvin (K)
. Radiative Zone: Temperature falls from about 7 million to about 2 million K across this zone. Convection Zone: drops from 2 million K to 5800K in this zone. Photosphere: about 5800K, although sunspots are about 3800 K – that’s why they are dark.
Is the temperature of the Sun increasing?
The Sun is becoming increasingly hotter (or more luminous) with time. … Astronomers estimate that the Sun’s
luminosity will increase by about 6% every billion years
. This increase might seem slight, but it will render Earth inhospitable to life in about 1.1 billion years. The planet will be too hot to support life.
How does the temperature and luminosity of the sun compare to other stars on the main sequence?
Stars on the Main Sequence that
are hotter than the Sun are also larger than the Sun
. So hot blue stars are more luminous (and therefore appear higher in this diagram) for two reasons: they are hotter, and hot objects are more luminous than cool objects, but they are also larger.
How will the sun’s luminosity and temperature change as it ages?
How will the Sun’s luminosity and temperature change as it ages?
It will eventually become less bright and cooler
.
What is the relationship between temperature and luminosity of most stars?
We can summarize this relationship by saying that
hotter stars are more luminous than cooler ones
. A number of stars, however, lie above the main sequence on the H–R diagram, in the upper-right region, where stars have low temperature and high luminosity.
Can two stars have the same luminosity and different temperatures?
Neither is more luminous.
Same size = same temp = same luminosity
(If 2 stars have the same surface temperature and size, then they both have the same luminosity.) … The star with a higher surface temperature is more luminous. (The higher temperature star is the more luminous, if they both have the same size.)
How hot is the Sun’s chromosphere?
the chromosphere is the innermost atmospheric layer. It is just above the photosphere. Here the temperature begins to rise again, to
about 36,000 degrees F.
Above the chromosphere is the transistion layer, where temperatures increase 6000 to over half-a-million degrees.
What determines luminosity of a star?
A star’s luminosity can be determined from two stellar characteristics:
size and effective temperature
. … An alternative way to measure stellar luminosity is to measure the star’s apparent brightness and distance.
What is hotter than the Sun?
According to NASA,
lightning
is four times hotter than the surface of the sun. … The air around a stroke of lightning can peak at 50,000 degrees Fahrenheit, while the surface of the sun is around 11,000 degrees. Meanwhile, magma can reach temperatures near 2,100 degrees.
What heats the chromosphere and corona?
In the chromosphere, almost all the mechanical energy flux supplied to the
outer solar atmosphere by magneto-convection
is converted into heat and radiation, leaving a small amount to power the solar wind and the hot corona: the chromosphere requires over 30 times more energy than the corona and heliosphere combined.
What layer of the Sun is the hottest?
Core
. The hottest part of the Sun is the core, at 28,080,000°F, on average.
What is the temperature of the topmost layer of the Sun?
The temperature in the photosphere varies between about 6500 K at the bottom and
4000 K
at the top (11,000 and 6700 degrees F, 6200 and 3700 degrees C).
Will the sun explode?
After the sun has burned through most of the hydrogen in its core, it will transition to its next phase as a red giant. At this point roughly 5 billion years in the future, the sun will stop generating heat via nuclear fusion, and its core will become unstable and contract, according to NASA.
What are the 7 layers of the Sun?
It is composed of seven layers:
three inner layers and four outer layers
. The inner layers are the core, the radiative zone and the convection zone, while the outer layers are the photosphere, the chromosphere, the transition region and the corona.
Why is the sun luminosity increasing?
The Sun fuses hydrogen to form helium, this creates heavier matter to clump up, and collectively
increase the temperature and pressure
—consequentially increasing the luminosity.
What makes the sun so hot?
The core of the sun is so hot
and there is so much pressure, nuclear fusion takes place: hydrogen is changed to helium. Nuclear fusion creates heat and photons (light). The sun’s surface is about 6,000 Kelvin, which is 10,340 degrees Fahrenheit (5,726 degrees Celsius).
How do you find luminosity?
If they know the star’s brightness and the distance to the star, they can calculate the star’s luminosity: [
luminosity = brightness x 12.57 x (distance)
2
]
. Luminosity is also related to a star’s size. The larger a star is, the more energy it puts out and the more luminous it is.
How do you find the luminosity of a planet?
Luminosity equation
T is the temperature of the body, expressed in Kelvins.
What would be the luminosity of the sun if its surface temperature were 3000 K and its radius were 1 AU?
What would be the luminosity of the Sun if its surface temperature were 3000 K and its radius were 7.0 AU ? 1 A.U. = 215 solar radii. L = 1505^2(3000/5800)^4,
L = 1.7×10^5 solar luminosities
.
What is the temperature and luminosity of the sun quizlet?
The Sun has a
temperature of 5800 K and a luminosity of 1 L☉
.
How does the sun’s luminosity compared to other stars?
In fact, the sun is
thought to be more luminous than 85% of the stars in our Milky Way galaxy
. Yet most of these less luminous stars are too small and faint to see without an optical aid. Let’s presume a star has the same surface temperature as the sun, but sports a larger radius.
What is Betelgeuse luminosity?
Betelgeuse’s luminosity is
100,000-times that of the Sun
. However, its surface is also cooler – 3,600 K versus the Sun’s 5,800 K – so only about 13% of its radiant energy is emitted as visible light. Traditionally, Betelgeuse is classified as a pulsating variable star.
What happens as the Sun ages?
Our star will grow to be larger than we can imagine — so large that it’ll envelope the inner planets, including Earth. That’s when the
sun will become a red giant
. For about a billion years, the sun will burn as a red giant. Then, the hydrogen in that outer core will deplete, leaving an abundance of helium.
What is the relationship between temperature and luminosity brightness )?
Brightness clearly increases with temperature
, and with any incandescent (glowing from heat) object, the hotter the object the bluer its light. What makes a star hotter is a more rapid rate of fusion in the core, which is driven by higher pressure from higher mass.
Do stars with the same temperature necessarily have the same luminosity?
Main sequence stars are luminosity class “V” whereas giant stars are luminosity class “II”. In this instance, the two stars have the same temperatures because they
are in the same spectral class
, but a luminosity class II star is larger and has a greater luminosity than a much smaller main sequence star.
What is the protostar stage?
A protostar is
a very young star that is still gathering mass from its parent molecular cloud
. The protostellar phase is the earliest one in the process of stellar evolution. For a low-mass star (i.e. that of the Sun or lower), it lasts about 500,000 years.
What is luminosity of a star?
Another measure of brightness is luminosity, which is the power of a star —
the amount of energy (light) that a star emits from its surface
. It is usually expressed in watts and measured in terms of the luminosity of the sun.
Which statement best describes the relationship between temperature and luminosity of a main sequence star?
Q. Which statement describes the general relationship between the temperature and the luminosity of main sequence stars?
As temperature decreases, luminosity remains the same.
What determines the temperature of a star?
What determines a stars (surface-)temperature is
how much energy is produced in its core, and how large its surface area is
. The bigger the surface area, the lower the surface temperature.
The surface temperature of
a star determines the color of light it emits
. Blue stars are hotter than yellow stars, which are hotter than red stars. … Remember that magnitudes decrease with increasing brightness, so if B – V is small, the star is bluer (and hotter) than if B – V is large.
Do stars have the same temperature?
As we have seen,
stars are not all the same color because they do not all have identical temperatures
. To define color precisely, astronomers have devised quantitative methods for characterizing the color of a star and then using those colors to determine stellar temperatures.
What are the spectral type temperature and luminosity of star A?
The star A is of spectral type B, having temperature in the
range of 17000 K −18000 K
. The star A has absolute magnitude of 0 to (−1) and luminosity of star A is 100 solar units.
Why does luminosity not depend on the distance of a star?
The luminosity of a star, on the other hand, is the amount of light it emits from its surface. The
difference between luminosity
and apparent brightness depends on distance. … However, apparent brightness is not an intrinsic property of the star; it depends on your location.
