All Questions
Tagged with absolute-magnitude observational-astronomy
3 questions
2
votes
1
answer
273
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What is the unit for 'magnitude' in terms of the Isophotal diameter of a galaxy?
Every site and AI and Google say that one way of measuring a galaxy's diameter is in terms of its isophotal diameter, using the blue D25 standard, using units of, "25 mag per arcsec2".
But ...
- 5,585
2
votes
1
answer
924
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Distance to star using color index
I'm doing the following question:
A star is observed with UBV magnitudes $m_u = 16.31$, $m_b = 14.52$,
$m_v = 13.76$. Spectral analysis gives $M_{bol} = 7.31$, $BC = -1.02$, $(U − B)_0 = 1.222$. ...
- 65
5
votes
0
answers
56
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In the JPL small body browser, why is uncertainty on absolute magnitude "N/A"?
In the JPL small body browser, orbital elements are all provided with uncertainties and even a covariance matrix, such as for 2013 LA2. Very good. But underneath, the absolute magnitude is reported ...
- 2,233