\documentstyle [adc,11pt]{article}
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\newcommand{\dmv}{Documentation for the Computer-Readable Version}
\newcommand{\cat}{A Catalogue of Linear Polarization Measurements for 5070
Stars}
\newcommand{\abbr}{LP}
\newcommand{\catref}{Axon and Ellis (1976)}
\newcommand{\pcatref}{Axon, D.J. and Ellis, R.S.}
\newcommand{\docnum}{NSSDC/WDC-A-R\&S 92-10}
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\begin{document}
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\title{\cat}
\author{(\pcatref)}
\docauthor{Nancy G. Roman}
\docno{NSSDC/WDC-A-R\&S 92-10}
\date{March 1993}
\maketitle

\begin{abstract}

The authors have collected and collated measurements of linear polarization of
starlight. These are presented in a catalog that lists the Stokes parameters
of linear polarization for stars with reliable distances. The authors from whom
data have been collected are Hiltner, Smith, Hall, Behr, Appenzeller, Mathewson
\& Ford, Klare {\em et al.}, and Schr\"{o}der.

\end{abstract}

\section{Introduction and Source Reference}

\subsection{Introduction}

The present catalog is based on the linear polarization measurements of eight
different sets of observers (see Table 1) of stars with reliable distances.
These require both color excesses and spectral types for the stars.

\begin{table} [h]
\centering
\begin{tabular}{ l r c l }
\hline
\multicolumn{1}{c}{Observer} &
\multicolumn{1}{c}{No. of Stars} &
\multicolumn{1}{c}{$\Delta$ P} &
\multicolumn{1}{c}{$\Delta \theta$} \\
 &\multicolumn{1}{c}{(approx.)}& (mag)  & \multicolumn{1}{c}{(deg)} \\
\hline                                          
Hiltner (1951-56)           &  1034   &  0.003         &  1- 7   \\
Smith (1956)                &   123   &  0.005-0.020   &  5-20   \\
Hall (1958)                 &  1329   &  0.005         &     8   \\
Behr (1959)                 &   550   &  0.0005        &  1-15   \\
Appenzeller (1966 and 1968) &   230   &  0.0003-0.0012 &  1-20   \\
Mathewson \& Ford (1970)    &  1800   &  0.0007        &  1-10   \\
Klare et al. (1971)    &  1600   &  0.001-0.004   &     5   \\
Schr\"{o}der (1976)         &   511   &  0.001-0.0024  &     2   \\
\hline
\end{tabular}
\caption{Sources of Data}
\label{t:sources}
\end{table}
\subsection {Source Reference}

\begin{references}

\item ``A Catalogue of Linear Polarization Measurements for 5070 Stars'',
Axon, D.J., and Ellis, R.S. 1976, MNRAS, 177, 499

\end {references}


\section {Structure}

\subsection{File Structure}

{\em A Catalogue of Linear Polarization Measurements for 5070 Stars} as
distributed here is in a single file. It contains 5064 records of 80 bytes
each, six of the entries proved to be duplicates.

This information is sufficient for a user to describe the indigenous
characteristics of the machine-readable version of {\em A Catalogue of Linear
Polarization Measurements for 5070 Stars} to a computer. A copy of this document
should accompany any additional copy of this catalog.

\subsection{File Format}                      

Table 2 gives a byte-by-byte description of the contents of the data file.

\begin{table} [h]
\centering
\begin{tabular}{ l l l l }
\hline
Bytes     & Unit   & Format  & Item                   \\ \hline
 1 -  6   &        & I6      & HD or other ID         \\
 8 - 15   & mag    & F8.5    & Stokes parameter Q     \\
17 - 24   & mag    & F8.5    & Stokes parameter U     \\
26 - 30   & deg    & F5.1    & Galactic longitude      \\
32 - 36   & deg    & F5.1    & Galactic latitude      \\
38 - 41   & pc     & I4      & Distance               \\
43 - 80   &        & A38     & Remarks                \\
\hline
\end{tabular}
\caption{Format }
\label{t:form}
\end{table}

The ``remarks'' in the catalog contain other catalog numbers and indicate the
most recent data by the author's name.

\section{Additional Remarks}

Duplicated measurements were identified and the preference given to the observer
whose quoted accuracy was higher.

The Stokes parameters are expressed in magnitudes and have been calculated from
the relations

\begin{displaymath}
Q = p\, cos\,2\left(\theta-\frac{\pi}{2}\right)
\end{displaymath}

\begin{displaymath}
U = p\, sin\,2\left(\theta -\frac{\pi}{2}\right)
\end{displaymath}

where {\em p} is the degree of polarization in magnitudes and $\theta$ is the
orientation of the E-vector increasing anti-clockwise from the north galactic
pole, i.e., $0\leq \theta \leq \pi$. To convert these values into percentage
polarization, scale both {\em Q} and {\em U} by 46.05. The typical errors in
{\em p} and $\theta$ quoted in Table \ref{t:sources} imply uncertainties of
about $0{.\!^{m}}0035$ in {\em Q} and {\em U}.  Distances were computed from the
spectroscopic absolute magnitudes in the usual way.

\section{Acknowledgments}

We thank Dr. Ellis for forwarding to us a machine-readable
version of the catalog.

\section{References}
\begin{references}
\item Axon, D.J., and Ellis, R.S. 1976, MNRAS, 177, 499
\item Appenzeller, I. 1966, Z. Astrofis., 64, 296
\item Appenzeller, I. 1968, ApJ, 151, 907
\item Behr, A. 1959, Ver\"{o}ff. U. Sternw. G\"{o}ttingen, no. 126
\item Hall, J.S. 1958, Publ. U.S. Naval Obs. 2nd ser. Vol. 17, No. VI
\item Hiltner, W.A. 1951, ApJ,  114, 241
\item Hiltner, W.A. 1954a, ApJ, 120, 41
\item Hiltner, W.A. 1954b, ApJ, 120, 454
\item Hiltner, W.A. 1956, ApJS, 2, 389
\item Klare, G. Neckel, Th., and Schnuur, G. 1971, A\&Am 11, 155
\item Mathewson, D.S. and Ford, V.L. 1970, MmRAS, 74, 139
\item Schr\"{o}der, R. 1976, A\&AS, 23, 125
\item Smith, E. van P. 1956, ApJ, 124, 23             
\end{references}
\end{document}
