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\IBVShead{5198}{10 November 2001}

\IBVStitletl{Photometry and Spectrophotometry}{  of the New Variable Star IRAS 20192+3025} 

\IBVSauth{West, J. D.$^1$; Alexander, D. R.$^2$}

\IBVSinst{Mulvane, KS, USA, e-mail: dwest61506@aol.com}

\IBVSinst{Wichita State University, Wichita, KS, USA, e-mail: david.alexander@wichita.edu}

\SIMBADobj{IRAS 20192+3025}
\IBVSabs{We present CCD V and Ic band photometry and spectrophotometry of the}
\IBVSabs{object IRAS 20192+3025. The results of this study indicate the object}
\IBVSabs{to be a red giant of  spectral type M4-6 with periodic variations in}
\IBVSabs{the light curve at 20.9 and 40.6 days. The resulting variability type}
\IBVSabs{is SRB.}

\begintext

IRAS 20192+3025 is a red giant star located at  R.A. = 20\hr 21\mm17\fsec48
DEC. =+30\deg 34\arcm 41\farcs6 (Equinox J2000, Epoch  2001.644).  Photometric and
spectrophotometric observations were taken at West Skies Observatory (MPC code
451) in Mulvane, KS, USA. The telescopes used were 0.2m and 0.25m
Schmidt-Cassegrains.  V and ${\rm I_{kc}}$ filters were used in conjunction with an SBIG ST-8 CCD camera.  The observations were reduced to the Johnson V and Cousins I
band photometric systems. The comparison star was HIP 100384 (V=6.77, B$-$V =
0.261 $\pm$ 0.011, V$-{\rm I_c}$ = 0.22 $\pm$ 0.03) and the check star was HIP
100369. The individual observations are available from the IBVS website as
5198-t1.txt .

\IBVSedata{5198-t1.txt}

\IBVSfig{8.5cm}{5198-f1.eps}{V band photometry of IRAS 20192+3025. The V band photometry demonstrates multi-periodic behavior.}


A spectrum was taken using a non-objective slitless spectrometer (West et
al. 2000).  The spectrometer consists of a Rainbow Optics grating
mounted to the CCD camera.  Wavelength calibration was accomplished using the
hydrogen lines from A type stars and a laboratory mercury emission lamp. The
wavelength accuracy is $\pm$ 20 \AA ngstr\"om.  The spectrum is flux calibrated
relative to Vega.  The ``+ Cont.'' term in the flux represents the difference in
air mass between the target star and the Vega calibration spectrum.  The
signal-to-noise for the spectrum is greater than 10. The slope of the spectrum
and the TiO band heads at 5167, 5847, 6536, 7054, 7594 \AA ngstr\"om are consistent
with a M4III star (Celis 1984, and Serote Roos et al. 1996). 

\IBVSfig{8.5cm}{5198-f2.eps}{A low-dispersion spectrum of IRAS
20192+3025 taken on 6/18/01 with a non-objective slitless spectrometer. The
TiO bands are evident.} 

%%Text file of the spectrum: iras20192_sp061801ut.txt


This variable star is not listed in the GCVS.  Based on the photometry and
spectrophotometry reported in this paper, the type of variability is
consistent with the SRB designation.  Averages for the photometry are: V =
10.74, ${\rm I_c}$ = 7.02, and V$-{\rm I_c}$ = 3.72. 
 Stars with this large a V$-{\rm I_c}$ fall into the M6 spectral class (Bessell). Analysis of the V and ${\rm I_c}$ band photometry with the computer program AVE shows a
multi-periodic waveform.  The two dominant periods from the 94 days of
observation are 20.9 $\pm$ 2.4 and 40.6 $\pm$ 1.3 days.  It is not yet clear if
these periods are significant, or if they represent independent  variations in
the brightness of the star. Observations over a longer
baseline will be required to resolve all of these issues.   Based on the
photometry and spectrophotometry one concludes that IRAS 20192+3025 is a M4III to M6III variable star of type SRB.

\references

Bessell, M. S., 1990, {\it Pub. Ast. Soc. Pacific}, {\bf 102} 1181

Celis S. L., 1984, {\it Astron. J.} {\bf 89}, 527

Serote Roos, M., Boisson, C., Joly, M., 1996, {\it Astron. Astrophys. Suppl.},
{\bf 117}, 93

West, J. D., Alexander, D. R., 2000, {\it Bull. Am. Ast. Soc.}, {\bf No. 32}, 688

\endreferences

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