<p>The title explains the questions. I don't find any problem with it. As If the two stars A and B do have equal absolute magnitude for some wavelength <span class="math-container">$\lambda_0$</span> then
<span class="math-container">$$M_A=M_B$$</span>
<span class="math-container">$$-5(\log d_A-1)+m_A=-5(\log d_B-1)+m_B$$</span>
<span class="math-container">$$m_A-m_B=5\log\left(\frac{d_A}{d_B}\right)$$</span>
I don't find any problem with this. But I'm not sure if this is true. Can any help me with this?</p>

CC BY-SA 4.0
2021-04-27T04:30:33.713Z
This is like asking "Is it possible that two people have the same height"...
James K
CC BY-SA 4.0
2021-04-27T05:17:54.710Z
This is trivially true, since for two sufficiently cold stars at sufficiently high measured wavelength, the magnitude of both stars will be zero. The non-trivial case, which is a specific wavelength for two stars that is non-zero and the same for both is perhaps more interesting.
Connor Garcia
CC BY-SA 4.0
2021-04-27T09:35:38.950Z
It can be formulated as how much their spectra depart from the black body one. And as for the previous comment, staying away from the tails..
Alchimista
<star><absolute-magnitude>
Is it possible that absolute magnitude for two stars is equal for some wavelength?
Himanshu
# Is it possible that absolute magnitude for two stars is equal for some wavelength?

(Asked by: username_0 on 2021-04-27)

The title explains the questions. I don't find any problem with it. As If the two stars A and B do have equal absolute magnitude for some wavelength $\lambda\_0$ then
$$M\_A=M\_B$$
$$-5(\log d\_A-1)+m\_A=-5(\log d\_B-1)+m\_B$$
$$m\_A-m\_B=5\log\left(\frac{d\_A}{d\_B}\right)$$
I don't find any problem with this. But I'm not sure if this is true. Can any help me with this?

**Tags:** star, absolute-magnitude

> **Comments:**
> **username_1**: This is like asking "Is it possible that two people have the same height"...  
> **username_2**: This is trivially true, since for two sufficiently cold stars at sufficiently high measured wavelength, the magnitude of both stars will be zero. The non-trivial case, which is a specific wavelength for two stars that is non-zero and the same for both is perhaps more interesting.  
> **username_3**: It can be formulated as how much their spectra depart from the black body one. And as for the previous comment, staying away from the tails..  

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## 0 answers

