Sharp EL-5230 User Manual download pdf (Page 114)

112

Example 1

What is the ratio of the sun’s luminosity to that of a star having an absolute

magnitude of 2.89?

(The sun’s absolute magnitude is 4.8.)

The former equation is equivalent to

1. Press b 0 and @ P 0.

2. Press @ Y ( 0.4 k (

4.8 - 2.89 ) ) e.

Result

5.807644175

The star is nearly six times as luminous as the sun.

Example 2

A second star has only 0.0003 times the luminosity of the sun. What is its

absolute magnitude?

The previous equation is equivalent to

1. Press 4.8 - ( l 0.0003 z 0.4 ) e.

Result

The absolute magnitude of the second star is

approximately 13.6.

Chapter 8: Application Examples

= M

– ————

where —— = 0.0003

log ——

0.4

4.8-(log0.0003

13.60719686

—— = 10

0.4 (M

– M

)

whereM

= 2.89

^(0.4˚(4.8-2.

89))=

5.807644175

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Sharp EL-5230 User Manual Page 114