Questions tagged [color-index]
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8 questions
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calculating the color of a galaxy and making the k correction
I want to know if this is correct:
I have in my dataset: $u_{mag}, u_{mag_{err}}, r_{mag}, r_{mag_{err}}$
Calculating the $u_{r_{color}}$:
$u_{r_{color}} = u_{mag} - r_{mag}$
$u_{r_{color_{err}}} = u_{...
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Why is the colour-index measurement used?
So I'm learning about the colour-index currently and what is confusing me is why this is useful. The colour of a star is dependent on the temperature, so wouldn't astronomers have a natural idea of ...
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Straightforward conversion from Gaia GDR3 photometry to RGB values
I'm a non-astronomer, but I'm working on a project for which I need to produce CGI renderings of as complete a starfield as I can find. The latest Gaia catalogue release has an impressive 1.5 billion ...
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E(B-V) , the color excess between B and V bands, for galaxy at redshift 0
Following Mo et al. 2010 (page 479), the quantity $E(B-V)$, called the color excess between B and V bands, is equal to:
$$E(B-V) = A_B - A_V = (B - V) - (B - V)_0 = (m_B - m_V) - (M_B- M_V)$$
where $...
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How to determine temperatures for a binary system?
How to make a guess for temperatures of an eclipsing binary from light curves measured in UBVR filters of the Johnson system? I assume that differences of indexes U, B, V will be necessary, right? ...
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What does the Reddening line represents in this U-B vs B-V plot?
The plot is from this paper (pg-8).
They have also talked(in the same paper) about how central stars from galactic longitude range $20^\circ-80^\circ$ will have a very unusual Reddening line (pg-9). ...
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Given that a color index ($B-V$) of star A is lower than that of Star B, What can we say about the stars?
The color index $B-V$ of the star is defined as
$$B-V\equiv M_B-M_V$$
Let us suppose it's given
$$(B-V)^{(A)}<(B-V)^{(B)}\Rightarrow M_B^A-M_V^A>M^B_B-M^B_V$$
The notations are a bit confusing, ...
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Corresponding BV Value to a Hertzsprung–Russell
I have an example BV value from an astronomical catalog of 1.04 (33 Psc, HD Catalog 28).
Given only the number 1.04, can that be charted on the HR, or do I need the individual components of the value ...
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