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\begin{document}

\IBVShead{5197}{10 November 2001}

\IBVStitle{USNO A 1125.14834179 is a Mira variable} 

\IBVSauth{Masi, Gianluca}

\IBVSinsto{Via Madonna de Loco, 47 03023 Ceccano (FR) Italy; e-mail: gianmasi@fr.flashnet.it}

\SIMBADobj{USNO-A2.0 1125-14834179}
\IBVStyp{ M }
\IBVSkey{Mira type star, photometry}
\IBVSabs{This paper reports about the discovery of a previously unknown}
\IBVSabs{variable star. A deep chart and unfiltered differential}
\IBVSabs{CCD photometry are reported ; a classification is proposed.}


\begintext


\smallskip

\IBVSTnam{A1125.14834179 in USNO A2.0}
\IBVSTcoo{19\hr 59\mm 41\fsec90}{+22\deg 33\arcm 50\farcs0}{2000.0}
\IBVSTobs{``Bellatrix'' Astronomical Observatory; 15cm, f/5 reflector}
\IBVSTdet{CCD SBIG ST-7 (based on the Kodak KAF0400 chip: 765*510 pixels)}
\IBVSTfil{None}
\IBVSTcomp{A1125.14828225 in USNO A2.0, $R=14\fmm5$}
\IBVSTchk{A star in the field (no ID available)} 
\IBVSTdata{Available through the IBVS web-site. (5197-t1.txt)}
\IBVSTtyp{  M  }


\IBVSedata{5197-t1.txt}

\IBVSTrem{
The V$-$C1 light curve shows a total magnitude range of about 2.7 mag., 
with a cycle-length of about 270 days (Figure 2), which is typical of Mira-type variables. The red colour of the star in the USNO-A1.0 catalogue indicated that it was a Mira or a semiregular variable (Skiff 1977), but it didn't appear in the IRAS point-source, the MSX and the 2MASS catalogues.
If we assume that the zero-point is close to the standard Cousins $R$ system, 
then the variable has a range of $13\fmm9<R<16\fmm5$. Since the variable is somewhat redder than the comparison stars, and given the extended red sensitivity of the unfiltered CCD, the true $R$ magnitudes are likely somewhat fainter. The {\it rms} scatter of the differential magnitude of C1$-$C2 is $0\fmm02$.
}

\newpage

\IBVSfig{6.5cm}{5197-f1.eps}{Identification chart for USNO A 1125.14834179.}

\vspace*{-1cm}

\IBVSfig{6.5cm}{5197-f2.eps}{Differential light curves of USNO A 1125.14834179$-$C1 and C1$-$C2.}


\IBVSTack{I wish to thank Brian Skiff (Lowell Observatory) and Taichi Kato (Kyoto
University) for their valuable suggestions at the very early discovery stages.
They have also kindly reviewed this manuscript.  Many thanks, finally, to all
the people who have given useful information during the first attempts to
verify the discovery. Bellatrix Observatory thanks Santa Barbara Instruments Group and
Software Bisque for their support.
}
 
\references

Monet, D., Bird, A., Canzian, B. et al. 1996, USNO-A2.0, (U.S. Naval Observatory, Washington DC)

Skiff, B. A., 1997,
http://www.kusastro.kyoto-u.ac.jp/vsnet/Mail/chat0/msg00487.html

\end{document}

