\documentstyle[twoside]{article}

\input ibvs2.sty

\begin{document}
\IBVShead{4969}{26 October 2000}

\IBVStitle{On the Variability of A3--F0 Luminosity Class III--V Stars}

\IBVSauth{Adelman, S.J.}

\IBVSinsto{Department of Physics, The Citadel, 171 Moultrie Street, Charleston, 
SC 29409, USA\\ \indent email: adelmans@citadel.edu}

\IBVStyp{ A, F }
\IBVSkey{photometry}
\IBVSabs{I investigate the Hipparcos Satellite photometry of A3-F0 stars of}
\IBVSabs{luminosity classes III-V to learn about their variability and} 
\IBVSabs{identify a few stars for which further study is desirable.}

\begintext

Several previous IBVS contributions (see, e.g., Adelman 2000) studied
the Hipparcos photometry (ESA 1997) of stars from various parts of the
HR Diagram in the Bright Star Catalogue, 5th edition (Hoffleit \&
Warren 1991) and the 4th edition Supplement (Hoffleit et al.\ 1983).
Here I examine the A3--F0 stars of luminosity classes III--V except for
those magnetic and non-magnetic CP stars which were studied by Adelman
(1998). These stars also include $\delta$~Scuti variables, Algol type
and other eclipsing binaries, W Ursae Majoris stars, microvariables,
constant stars considered as variable by some observer(s), and stars
with spurious variability due to duplicity, as well as nonvariable
stars.

Table 1 shows the mean amplitudes of A3--F0 luminosity class III--V
stars with at least 3 class members. When one allows for known
variables and statistics, the mean amplitudes appear to be smallest for
the A3--A7 III and A3--F0 IV stars with almost all averages indicating
that these are not very variable stars. These values are similar to
those found for B6--B9 III stars by Adelman, Gentry, \& Sudiana (2000)
and K0--K4 III stars by Adelman (2000). It is unlikely that all the
small amplitude $\delta$ Scuti stars have been found as those with
amplitudes comparable to the mean values were not readily discovered
using Hipparcos photometry. The averages for the luminosity class III
stars are similar to those of comparable luminosity class II stars
given by Adelman, Cay, Cay \& Kocer (2000).

Table 2 (available electronically from the IBVS site as 4969-t2.txt)
contains the values for the stars whose averages appear in Table 1 as
well as those which were not used in compiling these values, especially
with spurious variability due to duplicity. Table 3 lists stars whose
amplitudes of variability are a factor of order 1.67 or more greater
than the means (without known $\delta$~Scuti stars), usually 0\fmm04 or
greater. No known $\delta$~Scuti stars are included in this table.
Those stars which have not been classified as belonging to a known type
are in need of additional photometry. 

\IBVSedata{4969-t2.txt}

\IBVSetable{4969-t2.tex}

Table 2 also contains many stars with amplitudes of 0.01 which should
be considered as candidates for standard stars. A few are indicated to
have spurious variability due to duplicity, but may still be suitable
for certain applications. In addition 37~$\delta$~Cas is an eclipsing
binary star and 82 NT Peg is a $\delta$~Sct star. This indicates that
it would be desirable to check the literature of these stars for any
high quality photometry before using them as standards.

\bigskip
{\it Acknowledgements.\/} I wish to thank the Citadel Development Foundation for their support.

\begin{table}
\caption{The mean amplitudes of various types of A3 through F0 stars}
\begin{center}
\begin{tabular}{lrr@{ }l}
\hline
Spectral & \lower6pt\hbox{No.} & \multicolumn2l{\lower6pt\hbox{Mean amplitude (mag)}} \\[-4pt]
class & & \\
\hline
A3III & 15 & 0.023${}\pm{}$0.007 & (without EA HR 7422)\\
A4III & 11 & 0.020${}\pm{}$0.004 \\
A5III & 18 & 0.022${}\pm{}$0.008 \\
A7III & 30 & 0.029${}\pm{}$0.015 \\
 & 26 & 0.025${}\pm{}$0.009 & (without 4 0.05-0.07 mag. variables)\\
A8III & 11 & 0.019${}\pm{}$0.005 \\
A9III & 10 & 0.028${}\pm{}$0.008 \\
F0III & 42 & 0.030${}\pm{}$0.015 \\
 & 33 & 0.025${}\pm{}$0.009 & (without known $\delta$~Scuti stars)\\
A7III--IV & 6 & 0.022${}\pm{}$0.004 \\
A9III--IV & 4 & 0.035${}\pm{}$0.010 \\
F0III--IV & 3 & 0.027${}\pm{}$0.006 \\
A3IV & 29 & 0.022${}\pm{}$0.008 \\ 
A4IV & 12 & 0.022${}\pm{}$0.009 \\
A5IV & 15 & 0.022${}\pm{}$0.004 \\
A6IV & 5 & 0.020${}\pm{}$0.007 \\
A7IV & 18 & 0.024${}\pm{}$0.007 \\
A8IV & 7 & 0.023${}\pm{}$0.005 \\
A9IV & 10 & 0.026${}\pm{}$0.008 & (without $\delta$~Sct V376 Per)\\
F0IV & 50 & 0.023${}\pm{}$0.006 & (without $\delta$~Sct stars and known\\
 & & & photometric variable binaries)\\ 
A5IV--V & 8 & 0.024${}\pm{}$0.007 \\
A6IV--V & 3 & 0.033${}\pm{}$0.006 \\
A7IV--V & 5 & 0.026${}\pm{}$0.005 \\
A9IV--V & 3 & 0.027${}\pm{}$0.006 \\
F0IV--V & 10 & 0.028${}\pm{}$0.006 \\ 
A3V & 141 & 0.026${}\pm{}$0.030 & (without RZ Cas)\\
A4V & 56 & 0.027${}\pm{}$0.015 & (without V1031 Ori)\\
A5V & 61 & 0.024${}\pm{}$0.010 & (without V1010 Oph)\\
A6V & 16 & 0.026${}\pm{}$0.011 \\
A7V & 54 & 0.029${}\pm{}$0.025 \\
A8V & 27 & 0.028${}\pm{}$0.010 \\
A9V & 22 & 0.029${}\pm{}$0.007 & (without S Ant)\\
F0V & 80 & 0.028${}\pm{}$0.015 \\
\hline
\end{tabular}
\end{center}
\end{table}

\setcounter{table}{2}

\begin{table}
\caption{Some stars with amplitudes greater than stars of similar 
spectral type}
\begin{center}
\begin{tabular}{lrlrccl}
\hline
\lower6pt\hbox{Name} & HD & Spectral & HIP & SE & Amp. & \lower6pt\hbox{Comments} \\[-4pt]
& number & type & number & (mag) & (mag) & \\
\hline
 28 Peg & 210516 & A3III & 109458 & 0.0008 & 0.04 & \\
 & 16769 & A5III & 12821 & 0.0009 & 0.04 & P\\
 & 104664 & A7III & 58765 & 0.0008 & 0.04 &\\
 41 Vir & 112097 & A7III & 62933 & 0.0016 & 0.04 &\\
 & 141296 & A9III & 77574 & 0.0009 & 0.04 & \\
 & 118295 & A7--F0III & 66294 & 0.0008 & 0.04 & \\
 & 107054 & A9.5III & 60018 & 0.0008 & 0.04 & \\
$\upsilon^{1}$~Cnc & 72041 & F0IIIn & 41816 & 0.0017 & 0.05 & U\\
 & 111102 & F0III & 62428 & 0.0009 & 0.05 & \\
 36 Her & 150379 & A3IV & 81634 & 0.0010 & 0.04 & \\
 & 88987 & A9IV & 50305 & 0.0013 & 0.04 & \\
 & 69682 & F0IV & 40878 & 0.0010 & 0.04 & \\
 & 222226 & F0IV & 116699 & 0.0014 & 0.04 & \\
 & 55595 & A5IV--V & 34814 & 0.0010 & 0.04 & \\
 NSV 8183 & 155154 & F0IV--Vn & 83317 & 0.0010 & 0.04 & U\\
LR And & 1826 & A3V & 1799 & 0.0025 & 0.04 & ELL\\
 V773 Cas & 10543 & A3V & 8115 & 0.0011 & 0.05 & EA\\
 & 23055 & A3V & 17223 & 0.0010 & 0.04 & \\
42 V467 Per& 23848 & A3V & 17886 & 0.0017 & 0.05 & EB\\
 & 24805 & A3V & 18286 & 0.0009 & 0.04 & \\
 RR Lyn & 44691 & A3Vm & 30651 & 0.0009 & 0.36 & EA/DM\\
32~$\tau^{2}$~Hya & 82446 & A3V & 46776 & 0.0008 & 0.06 & U\\
 65 DN UMa & 103483 & A3Vn & 58112 & 0.0012 & 0.08 & EB\\
 NSV 5983 & 111604 & A3V & 62641 & 0.0018 & 0.04 & U\\
 & 168740 & A3V & 90304 & 0.0013 & 0.04 & MV\\
 & 195481AB & A3V & 101223 & 0.0010 & 0.04 & \\
 & 14213 & A4V & 10814 & 0.0016 & 0.04 & MV\\
 26 Cam & 38091 & A4Vn & 27249 & 0.0014 & 0.04 & NSV 2615, U\\
 & 82380 & A4V & 46873 & 0.0011 & 0.04 & \\
 22 Com & 109307 & A4V & 61295 & 0.0010 & 0.04 & \\
 & 130917 & A4V & 72552 & 0.0006 & 0.04 & \\
 & 215631 & A4V & 112725 & 0.0009 & 0.04 & \\
V343 Peg & 218395 & A4Vn & 114187 & 0.0015 & 0.12 & NSV 14430, U\\
 & 51335 & A5V & 33385 & 0.0014 & 0.04 & \\
$\pi$~Vir & 104321 & A5V & 58590 & 0.0008 & 0.04 & MV\\
V342 Peg & 218396 & A5V & 114189 & 0.0049 & 0.08 & P\\
 & 73819 & A6Vn & 42600 & 0.0012 & 0.04 & \\
 & 126859 & A6V & 70904 & 0.0014 & 0.05 & \\
 & 199986 & A5/7V & 103557 & 0.0014 & 0.04 & \\
DD Cam & 24733 & A7V & 18585 & 0.0062 & 0.19 & EB\\
 & 68457 & A7Vm & 40474 & 0.0015 & 0.04 & U\\
 & 76512 & A7V:n & 43853 & 0.0007 & 0.04 & \\
$\alpha$~Aql&187642 & A7V & 97649 & 0.0011 & 0.05 & EA\\
 \hline
\end{tabular}
\end{center}
\end{table}

\addtocounter{table}{-1}
\begin{table}[t]
\caption{(cont.)}
\begin{center}
\begin{tabular}{lrlrccl}
\hline
\lower6pt\hbox{Name} & HD & Spectral & HIP & SE & Amp. & \lower6pt\hbox{Comments} \\[-4pt]
& number & type & number & (mag) & (mag) & \\
\hline
 48 LMi & 94480 & A8V & 53355 & 0.0026 & 0.07 & U\\
 92 Vir & 121607 & A8V & 68092 & 0.0013 & 0.04 & U\\
 & 103928 & A9V & 58369 & 0.0010 & 0.04 & MV\\
 & 149989 & A8/F0V & 81650 & 0.0012 & 0.04 & P\\
 & 154660 & A9V & 83738 & 0.0018 & 0.04 & MV\\
 & 11100 & F0V & 8417 & 0.0015 & 0.06 & MV\\
9 V398 Aur & 32537 & F0V & 23783 & 0.0027 & 0.06 & SR\\
 V368 Pup & 58634 & F0V: & 35960 & 0.0020 & 0.05 & P\\
 & 82582 & F0V & 46963 & 0.0010 & 0.04 & MV\\
 30 LMi & 90277 & F0V & 51056 & 0.0007 & 0.04 & \\
 LL Vel & 96008 & F0V & 54060 & 0.0016 & 0.05 & ELL\\
 BW Boo & 128661 & F0V & 71487 & 0.0009 & 0.05 & EA/DM\\
 V533 Lyr & 172187 & F0V & 91250 & 0.0022 & 0.12 & EB\\
 & 204153 & F0V & 105769& 0.0007 & 0.04 & MV\\
\hline
\end{tabular}

\normalsize
\begin{tabular}{ll}
Notes:\\
EA = Algol type eclipsing binary & P = periodic variable \\
EB = eclipsing binary & SR = semi-regular variable \\
EW = W Ursae Majoris type variable & U = unresolved variable \\
MV = microvariable \\
\end{tabular}
\end{center}
\end{table}


\references

Adelman, S. J. 1998, {\it A\&AS}, {\bf 132}, 93

Adelman, S. J. 2000, {\it IBVS}, No.\ 4958

Adelman, S. J., Cay, I. H., Cay, M. T., Kocer, D., 2000, {\it IBVS}, No.\ 4947

Adelman, S. J., Gentry, M. L., Sudiana, I. M., 2000, {\it IBVS}, No.\ 4968

ESA, 1997, {\it The Hipparcos and Tycho Catalogs}, SP-1200

Hoffleit, D., Warren, W. H., Jr., 1991, {\it The Bright Star Catalogue}, 5th 
Rev.\ Ed., ADC Selected Astronomical Catalogs, Vol.~1, NASA Goddard Space 
Flight Center

Hoffleit, D., Saladyga, P., Wlasuk, P., 1983, {\it A Supplement to the Bright
Star Catalogue}, Yale University Observatory, New Haven, CT

\end{document}

