# Re Moon magnitude

From: michael.waterman@gecm.com
Date: Mon Mar 20 2000 - 03:39:00 PST

• Next message: Ted Molczan: "Lacrosse 2 & 3, USA 86, USA 102, USA 129 and OCS elements"

```(a) Russell Eberst pointed out a typo in the line beginning "or",
replace "ln" by "log10" so that it reads:
or -12.7 - 23.77*log10(sin(0.5*L))  where log10 is base 10.
However
(b) Rich Keen has more accurate magnitude data than mine, from the
book "Astrophysical Quantities" by C.W. Allen, University of London.
Comparing to full moon:
L        me    book   me-book
177     -0.02   0.05   -0.07
165      0.06   0.37   -0.31
124      1.26   1.51   -0.25
111      2.27   1.88    0.39
98      2.74   2.40    0.34
where the "me" column has been adjusted by the -0.28 from
my fit.

Since my observations had a standard deviation of 0.13, and the sd
of (me-book) is 0.29, I must have had some significant systematic
error - I dont know what. Experience shows my results are adequate
for sky brightness.

Doing an approximate fit to most of the book data we get:
L      Mag    Fit  Mag-Fit
180    0.00   0.00   0.00
170    0.23   0.27  -0.04
160    0.51   0.53  -0.02
150    0.79   0.80  -0.01
140    1.06   1.07  -0.01
130    1.35   1.35   0.00
120    1.62   1.64  -0.02
110    1.91   1.94  -0.03
100    2.24   2.26  -0.02
90    2.63   2.61   0.02
80    3.04   3.00   0.04
70    3.48   3.43   0.05
60    3.93   3.91   0.02
50    4.44   4.44  -0.00
40    5.07   5.05   0.02
30    5.90   5.75   0.15  ) Not included in
20    7.50   6.53   0.97  ) the fit.
where the fit is
fit = 1.52 * L2 + .038 * L2 * L2 * L2 * L2
and L2 = abs(180-L)*0.01745 = longitude from full moon in radians.

I would recommend using the above function instead of the function
in my March 17th email.

Mike Waterman      michael.waterman@gecm.com
Site Yateley = COSPAR 2115 =  51.3286N  0.7950W  75m.

-----------------------------------------------------------------
Unsubscribe from SeeSat-L by sending a message with 'unsubscribe'
in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org
http://www2.satellite.eu.org/seesat/seesatindex.html
```

This archive was generated by hypermail 2b29 : Mon Mar 20 2000 - 03:39:54 PST