# Extinction law -- How big is the extinction in the H-band?

• CharlesDamle
In summary, the H band has an extinction law of A_H = 0.591 * E(B - V) and in order to find the extinction in the H band, we need to calculate E(B-V) using the extinction in the V band. This can be done by using the given equation and the links provided. The introductory chapter of the textbook may also mention this equation.
CharlesDamle
Homework Statement
How big is the extinction in the H-band?
Relevant Equations
E(B-V) = A_B - A_V
Hey, I'm totally blank on this problem, and I'm not even sure what to solve for.

I'm told that the H band, which is in 1.63 μm, has an extinction law A_H = 0.591 * E(B - V) and I'm supposed to answer how big the extinction is in the H band.

And I'm confused because it involves the difference between the B and V band, and I'm not sure why I should use the wavelength of the H band. I'm tempted to say it is just 0.591
I'd appreiate any input.

Last edited:
No, it doesn't the equation, just states it in the introductory chapter.

CharlesDamle said:
No, it doesn't the equation, just states it in the introductory chapter.
So are you able to solve the problem now?

phyzguy said:
So are you able to solve the problem now?
Yes, I figured it out :)

phyzguy

## 1. What is extinction in the H-band?

Extinction in the H-band refers to the amount of light that is absorbed or scattered by interstellar dust in the H-band wavelength range. This can cause a decrease in the observed brightness of astronomical objects in the H-band.

## 2. How is extinction measured in the H-band?

Extinction in the H-band is typically measured using the H-band magnitude, which is the measure of an object's brightness in the H-band wavelength range. This magnitude is then compared to the intrinsic brightness of the object to determine the amount of extinction.

## 3. What causes extinction in the H-band?

The main cause of extinction in the H-band is interstellar dust. This dust is composed of small particles that absorb and scatter light in the H-band wavelength range, causing a decrease in the observed brightness of astronomical objects.

## 4. How does extinction in the H-band affect our observations of astronomical objects?

Extinction in the H-band can significantly impact our observations of astronomical objects, as it can cause a decrease in their observed brightness. This can make it difficult to accurately measure the properties of these objects, such as their distance, size, and temperature.

## 5. Can the extinction in the H-band vary across different regions of space?

Yes, the extinction in the H-band can vary across different regions of space. This is because the amount of interstellar dust can vary in different areas, leading to varying levels of extinction. This is important to consider when studying astronomical objects in different regions of space.

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