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5/2/05 8:36 PM
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jcuff
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Edited: 02-May-05
Member Since: 01/01/2001
Posts: 1704
 
Does anyone have any idea what the distance in parsecs an object is when the absolute magnitude (M) is -22 and the apparent magnitude (m) is 14.52? The formula I am working with is; logD=m-M+5/5 but the answer I am getting just does not seem right. Any help is appreciated. Thanks in advance!...Joe
5/2/05 10:24 PM
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Andrew Yao
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Edited: 02-May-05
Member Since: 01/01/2001
Posts: 2781
That should be log_10 D = (m - M + 5)/5. Then, D = 10^((m - M + 5)/5) M:=-22;
m:=14.52;
10^((m - M + 5)/5); = 2.01e8 parsecs. That seems really far, but think about it, the lower the magnitude, the higher the brightness. From 10 parsecs, it has magnitude of -22, so it looks extremely bright. In comparison the sun has a magnitude of -26.8 from earth. From where it is now, it has a magnitude of 14.52, which is tremendously dimmer considering magnitude is a logarithmic scale. So it must be very far away, much farther than 10 parsecs.

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