Wien's Displacement

[ma1ic3]

I am trying to figure out the peak wavelength emitted by a black body at x temperature.

Apparently this is done using Wien's Displacement which is:
Peak Wavelength in meters = Wien's Constant meter-Kelvin / Temperature in Kelvin

Wien's Constant = 0.0028977685.

Using this number I seem to be off 4 decimal places when I compare it to other people's answers. What is it that I am doing wrong?

For example, to find the peak wavelength emitted by the surface of the Sun I get this: 0.0028977685 / 5700 = 50.83 micrometers. But everyone else gets 508 nanometers.

[Art Vandelay]

Can you show your work?

[ma1ic3]

There isn't much to show. Most people use the Sun's temperature as an example. I can't seem to get the right answer, which should be fairly close to 500 nanometers.

There equation looks really simple, I can't figure out what I could possibly be doing wrong. It looks like Wien's Constant should be 0.00000028977685 instead of 0.0028977685.

[Art Vandelay]

My work:

Wien's constant: 2.9e-3
Temp: 5.7e3
W/T=2.9/5.7e-6=5.1e-7=510 nanometers

Your work?

[ma1ic3]

How is E-7 nano though? Isn't that micro? On the chart below it shows nano starting at E-9.

http://www.unc.edu/~rowlett/units/prefixes.html

[Art Vandelay]

I screwed up some of my work

Wien's constant: 3e-3
Temp: 6e3
W/T=(3e-3)/(6e3)=(3/6)e-6=.5e-6=500e-9=500 nanometers.

[ma1ic3]

Ok, looking at that, I think I am just confused about how numbers below 1 differ from those above 1. Is 500 billionths equivalent to 50 millionths? Kind of like how 1000 million is equivalent to 1 billion?

[Art Vandelay]

500 billionths is half a millionth. One millionth is 1000 billionths.

[Yllanes]

How is E-7 nano though? Isn't that micro? On the chart below it shows nano starting at E-9.

http://www.unc.edu/~rowlett/units/prefixes.html

10-7=100·10-9

50 micrometres would be 5·10-5=50·10-6, not 5·10-7.

[ma1ic3]

Ya ok, thanks.