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\input ibvs2.sty

\begin{document}
\IBVShead{6071}{19 August 2013}

\IBVStitletl{Time-Series Photometry of the Symbiotic Nova}{ NSV~11749 and New Variable Stars in Aquila}

\IBVSauth{Wehrung, M.$^1$; Layden, A.$^1$; Rogel, A.$^1$; Reichart, D.$^2$; Ivarsen, K.$^2$; Haislip, J.$^2$; Nysewander, M.$^2$; LaCluyze, A.$^2$}

\IBVSinst{Physics \& Astronomy Department, Bowling Green State
University, Bowling Green, OH 43403, USA}
\IBVSinst{Department of Physics \& Astronomy, University of North Carolina, Chapel Hill, NC, USA}

\SIMBADobj{NSV 11749}
\SIMBADobj{HBHA -0201-01}

\begintext

The ChaMPlane project (Grindlay {\it et al.} 2005) is a survey to
detect and optically identify low-luminosity X-ray point sources in
the Galactic plane, with the goal of characterizing the Galactic
distribution of accretion-powered sources such as X-ray binaries and
cataclysmic variable (CV) stars.  X-ray data were collected from
archival deep ($>20$ ks) Galactic plane ($|b| < 12^\circ$) fields,
while photometric $V$, $R$, $I$, and $H\alpha$ data were obtained
using CTIO and KPNO 4.0 m telescopes.  Multi-fiber spectroscopy was
obtained of stars with H$\alpha$ excesses to separate CVs from other
objects such as chromospherically active red dwarfs based on Doppler
broadening of the H$\alpha$ line (Rogel {\it et al.} 2006).  A number
of potential CV candidates were found, including a bright one with $R
\approx 14$ mag which coincided with the emission object HBHA~-0201-01
(Kohoutek \& Wehmeyer 1997).  Figure~1 shows the spectrum of this star
taken with the WIYN 3.5 m telescope.  The hydrogen and helium emission
lines are overlaid on a very late-type stellar continuum, indicating a
hot source
in proximity to a cool star, suggestive of a CV or other
accretion-powered system.  

Meanwhile, Williams (2005) presented a significantly revised position
of NSV~11749, a star discovered to be variable by Luyten (1937).  This
position corresponds to the CV candidate discussed above.  Williams
derived photometry from plates in the Harvard collection, showing an
outburst {\it circa} 1903 reaching a photographic magnitude of 12.5,
then slowly fading to go below the plate limit, $m_{pg} \approx 15$
mag, by 1912.  It remained below this limit through 1988, the end of
the plate sequence, though it was detected on a few deeper plates at
$\sim $17 mag.  Based on this outburst, Williams suggested that
NSV~11749 is either a slow nova or a FU Orionis pre-main sequence
star.

Miller Bertolami {\it et al.} (2011) compared the outburst light curve
of NSV~11749 with the outbursts of V605~Aql and V4334~Sgr, two objects
widely accepted as ``born-again'' asymptotic giant branch (AGB) stars.
In these stars, a very late thermal pulse ignites helium burning in a
star transitioning from the AGB to the top of the white dwarf
sequence, causing the star to return temporarily to the tip of the
AGB.  Based on light curve similarities and fits of thermal pulse
models to the observations, Miller Bertolami {\it et al.} (2011)
suggested that NSV~11749 is also a born-again AGB star.
Bond \& Kasliwal (2012, hereafter ``BK12'') presented optical and
infrared spectra of NSV~11749 showing Balmer and helium emission lines
on a continuous spectrum of a late type star (they estimated M1-M2 III
spectral type), much like our Figure 1.  These
spectra contrast sharply with that of the born-again star V605~Aql by
Clayton {\it et al.} (2006), which shows high excitation lines of
helium, carbon and oxygen, indicative of a hot, compact, hydrogen-poor
object.  While both objects underwent outbursts about a century ago,
these recent spectra show that the born-again AGB star has returned to
its former state as a young white dwarf, albeit dust-enshrouded, while
NSV~11749 has the spectral characteristics of an accreting compact
binary.  Thus, BK12 clearly showed that NSV~11749 is not a born-again
AGB star.

BK12 argued that NSV~11749 is a symbiotic star, a compact object (likely
a white dwarf) accreting matter from a giant star, rather than a dwarf
star in a traditional cataclysmic variable.\footnote{The powerful
outburst of 1903 resembles the 1980 outburst of the symbiotic nova PU
Vul shown in Figure 4 of Mikolajewska (2010), who provides a review of
this rare subclass of symbiotic stars.}  They based this distinction on
the presence of the broad emission feature at 6825 \AA ~due to Raman
scattering by neutral hydrogen, a feature only seen in symbiotic stars
(hereafter ``SSs'').  Unfortunately, this feature is just off the red
end of our spectrum, so we cannot confirm its presence.  However, our
spectrum has much higher signal-to-noise ratio than that of BK12, enabling us
to see more clearly the bands of molecular titanium oxide in the
stellar continuum.  The lower panel of Figure 1 shows our spectrum
divided by template spectra of M3, M4, and M5 III stars from Pickles
(1998).  A spectrum between M3 and M4 provides the best match, leaving
little residual signature of the TiO bands.  A smoothed version of the
resulting curve is the inverse of the function needed to
flux-calibrate our original spectrum, convolved with the interstellar
reddening function.

\vspace*{-3.5cm}

\IBVSfig{12cm}{6071-f1.eps}{{\bf Top-left:} the ChaMPlane spectrum
of NSV~11749 (not flux calibrated).  {\bf Top-right:} a detail of the
H$\alpha$ line. {\bf Bottom:} the NSV~11749 spectrum divided by
template spectra of M3, M4, and M5 III stars (lower, middle, and upper
curves, respectively).}  \IBVSfigKey{wehrung-f1.eps}{NSV~11749}{}
\IBVSfigKey{6071-f1.eps}{NSV 11749}{spectrum}

\vspace*{-0.5cm}

BK12 matched their spectra with templates of M1 and M2 giants using a
reddening function for $E(B-V) = 0.75$ mag.  Had they used an M3 or M4
template, a lower reddening would be needed, trending toward the value
of $E(B-V) = 0.67$ mag given by the dust maps of Schlegel, Finkbeiner
\& Davis (1998) at the location of NSV~11749, $(l, b) =
(34\fdeg8313, -3\fdeg5974)$, or $E(B-V) = 0.57$ mag from the
recalibration by Schlafly \& Finkbeiner (2011).  The spectral type
difference may also reflect a change in the intrinsic color of the
red giant if the star is a long period variable; our spectrum was
taken on 2007 June 20 {\it versus} 2012 for BK12.

Reddenings from the dust maps are uncertain at low latitudes, so we
compared the $R-I$ color of NSV~11749 (see below) with de-reddened
$R-I$ colors of M3 and M4 giants in the Bright Star Catalog (Hoffleit
\& Jaschek 1991).  This suggested an even lower reddening, $E(B-V)
\approx 0.1$ mag, but the large range in intrinsic color at fixed
spectral type and the effect of the hot companion star on the
intrinsic $R-I$ of the red giant in NSV~11749 leave a very large
uncertainty in this value.  As usual, finding the reddening of a low
latitude object is difficult.

The Williams (2005) photometry suggests NSV~11749 has been in a
quiescent state since the nova outburst 110 years ago, but no
time-series photometry is available since 1988, the last plate in
Williams' sequence.  We therefore undertook CCD photometry of
NSV~11749 to provide a clearer understanding of its nature in
quiescence, to confirm that its photometric behavior is consistent
with its spectroscopic identification as a symbiotic nova, and to seek
the orbital period as suggested by BK12.  Here, we report the results of
the first six months of photometric monitoring.

Images were acquired with the Bowling Green State University 0.5 m
$f/8$ Cassegrain telescope and Apogee AP6e CCD camera from 2012 May 16
through July 11.  The camera has a 21 $\times$ 21 arcmin field of view
with 1.2 arcsec pixels.  Images were taken in $V$ (180 s) and $I$ (120
s) and the star was visited at least twice each night, with each visit
consisting of three images per filter, dithered to prevent stars from
repeatedly landing on bad pixels.  On one night, we visited the field
ten times over an interval of 4.5 hours, and on two nights we visited
continuously over 1-2 hours to search for short term variations.
Preliminary photometry of the Bowling Green (BG) images indicated the
star was variable, but exhibited a slow brightening over the 60 day
interval with little short term variation.

We therefore initiated observations with the PROMPT $\#$5 0.4 m
telescope (P5; Reichart {\it et al.} 2005) located on Cerro Tololo in
Chile, which we used from 2012 July 24 through November 17.  We
visited the field one night each week, taking three images each in $V$
(60 s), $R$ (30 s), and $I$ (20 s).  The darker skies in Chile yielded
higher quality $V$ images than we obtained from BG, though the camera
field of view is smaller (10 $\times$ 10 arcmin).  The images from
BG and P5 were processed to remove the bias level and dark current,
and to flatten sensitivity differences across the chip.

The images were analyzed using the DAOPHOT II point-spread function
fitting photometry package (Stetson 1987).  Combined use of DAOPHOT
and ALLSTAR located all possible stars on each image. Because the
seeing and sky background varied from one image to the next, the
number of stars detected also varied. To create a more uniform object
list, the best quality images in $V$, $R$ and $I$
were combined using MONTAGE to produce master images with high
signal-to-noise. The DAOPHOT/ALLSTAR procedures were then applied to
these master images, giving a master list of stars in the field. Stars
were matched on each frame using DAOMASTER, and ALLFRAME (Stetson
1994) was run on all images using the master list from the respective
MONTAGE images to produce both time-averaged and time series
photometry for each star detected in the field.

\begin{table}[!hr]
\small
\centerline{{\bf Table 1.} Photometric Calibration.} 
\begin{center}
\begin{tabular}{ccrrrrrr}
\hline
  Date & Telescope & rms$_V$ & rms$_R$ & rms$_I$ & $N_{\rm std}$ & $N_{\rm fld}$ & $N_{SS}$ \\
\hline
 2012 Jul 10 & BG  & 0.027   &  ...    &  0.031  & 76 & 13 & 12 \\
 2012 Jul 11 & BG  & 0.043   &  ...    &  0.041  & 41 &  6 & 12 \\
 2012 Nov 17 & P5  & 0.022   &  0.021  &  0.023  & 60 &  8 &  3 \\
\hline
\end{tabular}
\end{center}
\vspace*{-0.5cm}
\end{table}

On two photometric nights in BG and one at P5, images of standard
stars (Landolt 1992) were taken over a range of airmass throughout
the night. The instrumental aperture magnitudes of these standard
stars, along with their $V-I$ color and airmass, $X$, were used to do
least-squares fits,
\begin{equation}
  m - M = c_0 + c_1 X + c_2(V-I),
\end{equation}

\noindent where $m$ is the instrumental magnitude and $M$ is the standard
magnitude. For July 11, a linear time dependent term was added.  
Table~1 shows the dates of each night, the rms scatter of each fit,
the number of standard stars observed, the number of independent
visits to standard fields, and the number of observations made of the
SS field.  We then used the ``$c_i$'' coefficients to standardize the
instrumental magnitudes of 15 uncrowded, non-variable stars in the SS
field to serve as comparison stars for differential photometry of the
variable stars.  Given the details of our calibration, we estimate the
final photometric zero-points on the comparison stars to be accurate
to 0.01-0.02 mag in $V$ and $I$ and to $\sim$0.04 mag in $R$.  The
larger value for $R$ reflects that data were taken on a single night
at high airmass.  The quality of our zero-points are demonstrated by
comparing our $V$ photometry to that in the APASS
database.\footnote{Data Release 7, 2013 by the AAVSO, see
\tt{http://www.aavso.org/apass}.}  We find a median difference of
$V_{\rm BG} - V_{\rm APASS} = -0.012 \pm 0.011$ mag for 14 stars in common,
with the uncertainties of the individual magnitudes being 3-5 times
larger in APASS than in ours.

\vspace*{-3.0cm}

\IBVSfig{12cm}{6071-f2.eps}{A color-magnitude diagram of the $10
\times 10$ arcmin P5 field around NSV~11749.  The error bars and
reddening vector are described in the text.  The red circles and
numbers mark the positions of the variable stars in Table 3; NSV~11749
is \#417.}  \IBVSfigKey{6071-f2.eps}{NSV 11749; variable stars}{other}

\vspace*{-0.5cm}

We also used these results to calibrate the time-averaged ALLFRAME
photometry from P5 and produce a color-magnitude diagram of the field,
which is shown in Figure~2.  There are 7867 stars in total, of which
547 are brighter than $V = 17$ mag.  The error bars along the right
show mean errors in magnitude and color for stars binned by $V$
magnitude.  The pattern of bluer, main sequence disk stars and redder
stars that include red giants is commonly seen in fields close to the
Galactic plane (e.g., Ortolani, Bica \& Barbuy 1993).  The reddening
vector is based on $E(B-V) = 0.67$ mag at the location of NSV~11749
(Schlegel, Finkbeiner \& Davis 1998).  There is no evidence for strong
variations in reddening across our field, either from the dust maps,
from inspection of our images, or from the the color-magnitude
diagram.


When compiling photometry using DAOMASTER, each star is labeled with a
variability index.  Stars with the highest variability index were
flagged in each of the five data sets ($V$ and $I$ from BG, and $V$,
$R$, and $I$ from P5), and these lists were compared to find stars in
common.  Through this method, we detected nine variable stars;
NSV~11749 was below our initial detection threshold, but we extracted
its photometry and found it to have low-level variations.  Equatorial
coordinates for each star were estimated from the Two-Micron All Sky
Survey images (Skrutskie {\it et al.} 2006).  These and the ($x$, $y$)
coordinates on a master image\footnote{A FITS format image
corresponding to these ($x$, $y$) coordinates is available at \hfill\break {\tt
http://physics.bgsu.edu/\~{}layden/publ.htm} along with other data products
from this research. The files are also available as 6071-d1.tar.gz from the IBVS website.} are shown in Table~2, along with a column
indicating in which fields of view the star was visible.  We searched
the SIMBAD database at the equatorial coordinates of each star (see
Table 2), and followed up named objects with the International
Variable Star Index.\footnote{The VSX is available at
\tt{http://www.aavso.org/vsx/}.}  The results are discussed below,
star by star.

\begin{table}[!hr]
\small
\centerline{{\bf Table 2.} Variable Star Coordinates.} 
\begin{center}
\begin{tabular}{rrrcccl}
\hline
ID\# &   $X_{\rm pix}$      & $Y_{\rm pix}$  &  RA (J2000)   &  Dec (J2000)  &  FOV & Name \\
\hline
417  &  485.1 & 547.1 & 19:07:42.4 & +00:02:51 & BG + P5 & NSV~11749 \\
  1  &  460.8 & 331.4 & 19:07:44.3 & +00:07:10 & BG + P5 & ASAS~190744+0007.1 \\
 26  &  325.9 & 414.7 & 19:07:55.1 & +00:05:30 & BG + P5\\
 27  &  546.4 & 381.8 & 19:07:37.5 & +00:06:09 & BG + P5 & IRAS~19050+0001\\
 62  &  485.0 & 571.2 & 19:07:42.4 & +00:02:22 & BG + P5\\
 85  &  637.9 & 832.3 & 19:07:30.2 &--00:02:51 & BG \\
132  &  885.6 & 784.6 & 19:07:10.4 &--00:01:55 & BG \\
244  &  700.9 & 640.0 & 19:07:25.1 & +00:00:59 & BG + P5\\
255  &  407.9 & 412.6 & 19:07:48.5 & +00:05:32 & BG + P5\\
419  &  800.6 & 655.5 & 19:07:17.2 & +00:00:40 & BG \\
\hline
\end{tabular}
\end{center}
\vspace*{-0.4cm}
\end{table}

\AladinChart{6071-t2}
\IBVSecomment{Aladin view of stars in Table 2}

We paired each variable with as many of the comparison stars as
possible ($N_{\rm comp}$), then calculated the differential photometry of
each pair from the ALLFRAME time-series data, and transformed the
result to the standard $VRI$ system, taking the median magnitude of
the $N_{\rm comp}$ measurements to represent the magnitude of that
variable on that image.  We adopted the standard error of the
$N_{\rm comp}$ measurements as the random uncertainty in that magnitude.
The calibrated time series photometry for each variable is available
electronically.  Figures~3--6 show the time series after multiple
observations taken on a single night were medianed; the error bar on a
given point shows the standard error of the $N_{\rm obs}$ magnitudes
measured that night.

Table~3 shows the median, maximum (max) and minimum (min) brightness
in $V$ and $I$ for each star, along with its median color.  From
Table~3 it is clear that all ten variables are extremely red, and the
color-magnitude diagram shows that they are among the reddest stars in
this 
field.  As the bluest of the ten variables, NSV~11749, with its very
late-type stellar continuum, sets a temperature upper limit on the
other variables.  Thus, they are likely to consist of, or contain, red
giant or red dwarf stars.  Unfortunately, only NSV~11749 was the
target of a ChaMPlane spectrum, so no spectral information is
available for the other variable stars.

Inspection of the light curves provided approximate periods for most
stars, and the ones with more regular periods were investigated using
the phase dispersion minimization method.  Also, for some
stars we applied the template fitting program of Layden (1998) to fit
ten standard light curve shapes 
to the data for each star to provide a best-fit amplitude
and to provide an objective means for classifying the variability type
based on light curve shape.


\begin{table}[!hr]
\small
\centerline{{\bf Table 3.} Photometric Characteristics. }
\begin{center}
\begin{tabular}{rrrrrrrccc}
\hline
 ID & $\langle V \rangle$ & $V_{\rm max}$ & $V_{\rm min}$ & $\langle I
\rangle$ & $I_{\rm max}$ & $I_{\rm min}$ & $\langle V-I \rangle$ &
Period & Type \\
\hline
417 & 15.75 & 15.61 & 16.17 & 12.76 & 12.70 & 12.84 & 2.99 & ? & Z And \\
  1 & 11.69 & 11.55 & 11.84 &  7.43 &  7.25 &  7.51 & 4.26 & 40-50 & Lb \\
 26 & 13.85 & 13.51 & 14.17 & 10.13 &  9.91 & 10.25 & 3.72  & $73 \pm 2$ & SR   \\
 27 & 15.45 & 15.00 & 17.16 &  9.21 &  9.01 & 10.31 & 6.24 & $>200$ & M \\
 62 & 14.82 & 14.48 & 15.32 & 10.69 & 10.57 & 10.97 & 4.13 & 58/116 & SRa/EW?   \\
 85 & 14.94 & 14.84 & 15.09 & 10.78 & 10.76 & 10.88 & 4.15 & ? & Lb?  \\
132 & 15.55 & 15.38 & 15.76 & 11.02 & 10.95 & 11.11 & 4.54 & ? & Lb?  \\
244 & 15.71 & 15.32 & 16.03 & 11.87 & 11.70 & 12.02 & 3.84 & $61 \pm 5$ & Lb  \\
255 & 15.75 & 15.48 & 15.94 & 12.01 & 11.92 & 12.06 & 3.74 & $47 \pm 3$ & Lb  \\
419 & 16.48 & 16.26 & 16.77 & 12.39 & 12.36 & 12.71 & 4.10 & ? & ? \\
\hline
\end{tabular}
\end{center}
\vspace*{-0.4cm}
\end{table}


In Figure~3, the symbiotic star, NSV~11749 (ID \#417), shows a gradual
increase in $V$ and $I$ over the course of the BG observations, and a
gentle decline in $VRI$ during the P5 interval.  The scatter in the BG
$V$ data is mostly observational, as the star was quite faint relative
to the background sky.  However, the slight variability seen in the P5
data seems to be correlated between $VRI$, so is probably real, with a
time scale of roughly 40 days.  The star showed no evidence of short-term
variability ($\sigma < 0.015$ mag) over the three nights of
high-cadence $I$-band observing from BG.  Flickering due to variable
accretion rates cannot be ruled out completely, however, since the
cool red giant may dominate any flux variations due to accretion onto
the hot companion.  We intend to obtain high cadence observations in $UBV$ 
to seek evidence for a variable accretion rate.

These limits on variability over the 1-5 hour time scale support the
claim of BK12 that NSV~11749 is a rare symbiotic star, rather than a
more common cataclysmic variable.  Brightness modulations due to
orbital effects should be evident if the star were a CV, which
typically have orbital periods of hours (e.g., Warner 1995).  Also,
the lack of outbursts over the 184 days of observation is unusual for
typical dwarf nova systems (Sterken \& Jaschek 1996).

The slow variation seen in Fig.~3 is consistent with the behavior of
symbiotic stars (Z Andromedae type; Sterken \& Jaschek, 1996), in
which the hot spot or accretion disk contributes the H and He emission
lines seen in Fig.~1, while our $I$ photometry is dominated by the
light of a red giant companion.  The orbital periods of SSs are
typically hundreds to thousands of days, with the very rare subclass
of symbiotic novae having periods greater than 800 days (Mikolajewska
2010).  It is not clear from the small fraction of a light cycle seen
in our photometry whether the behavior is sinusoidal, and indicative
of the orbital period of an tidally-distorted red giant, or asymmetric
and indicative of Mira-type pulsations seen in the secondaries of many
symbiotic novae (Mikolajewska 2010).  However, the colors and spectral
type of NSV~11749 indicate a star hotter than the Mira variable \#27,
so as we gather more data in the coming years, we anticipate seeing an
elliptical light curve with a period of $\sim$3 years.

Figure~4 shows the light curves of star \#1.  Despite being the
brightest star in the field and saturated on some images, the star is
clearly variable with a low amplitude ($\Delta V \sim  0.3$) mag and
irregular cycle (40-50 days between peaks).  The All Sky Automated
Survey (ASAS; Pojma\'{n}ski \& Maciejewski 2005) also detected this
star, labeled ASAS 190744+0007.1, as variable with a mean $V$ of 11.41
mag and a $V$ amplitude of 0.35 mag.  The period given by ASAS is 57.9
days, but they were unable to ascribe a variable type to the star; it
is listed as ``MISC.''  A time-magnitude plot of the ASAS data shows
no regular periodicity, and the time and amplitude scales of the
variability come in and out of coherence over months to years.  Our
photometry is consistent with the behavior seen in the ASAS
photometry.  Given the irregular behavior seen in both data sets, the
lack of variation over hours, and the extremely red color of the star,
we believe this star is a low-amplitude irregular pulsating giant
star, type ``Lb'' in the GCVS notation (Samus {\it et al.}  2012).

\IBVS2fig{7.5cm}{6071-f3.eps}{Light and color curves for NSV~11749 (ID\#417) where the $V$ and $R$ data ($\bigcirc$ and $\triangle$) have been shifted upward by 2.0 and 1.0 mag, respectively, for ease of display.  The solid squares and line ($V_C$) show photometry of the non-variable star \#127 for comparison.  The arrow indicates the transition from BG to P5 data.}{6071-f4.eps}{Light curves for stars \#1, \#26 and \#27.  Symbols are as in Fig. 3. Error bars in Figs. 3-6 are described in the text.}  
\IBVSfigKey{6071-f3.eps}{NSV 11749}{light curve}
\IBVSfigKey{6071-f4.eps}{NSV 11749; ASAS 190744+0007.1; IRAS 19050+0001}{light curve}

\IBVS2fig{7.5cm}{6071-f5.eps}{Light curves for stars \#62, \#244 and \#255.  Symbols are as in Fig. 3.}{6071-f6.eps}{Light curves for the three stars viewed only from BG: \#85, \#132 and \#419.  Symbols are as in Fig. 3.}
\IBVSfigKey{6071-f5.eps}{variable stars}{light curve}
\IBVSfigKey{6071-f6.eps}{variable stars}{light curve}

The light curves for star \#26, shown in Fig. 4, indicate a more
consistent periodicity of $73 \pm 2$ days over 2.5 light cycles, while
the amplitude varies considerably from cycle to cycle.  These and the
star's red color suggest this star is a semi-regular (SR) long period
variable.  Our continuing observations will determine the level of
periodicity and hence the sub-category SRa versus SRb.

The classification of star \#27, also shown in Fig. 4, is clearer: it
must be a Mira (M) type long period variable with a period longer
than 200 days and an amplitude $\Delta V > 2.2$ mag.  Continuing
observations will refine these values.  This very red star is 7.5
arcsec from the cataloged position of IRAS 19050+0001 and is almost
certainly a match.

Star \#62, shown in Fig. 5, has a regular periodicity superimposed on
a linear decline over the 184 day observing interval.  After fitting
and removing the linear trend, we obtained a period of $58 \pm 3$
days.  This could be interpreted as an SRa long period variable with a
long secondary period (e.g., Kiss {\it et al.} 1999), or a contact
binary (EW type) in which both components are giants and one has slow,
low-level pulsation.  Template fitting using the 58 day period
resulted in a best fit using a sine curve template with an amplitude
of 0.31 mag in $V$ and 0.14 mag in $I$, while a 116 day period yielded
an EW template with amplitudes of 0.34 and 0.14 mag, respectively.  The
rms scatter around the templates was comparable, giving us no reason
to prefer one fit over the other.  More photometric observations may
clarify these two interpretations.

Stars \#244 and \#255 have similarly red colors and irregular light
curves in terms of both period and amplitude (see Fig. 5).  We
classify them both as irregular long period variables of class Lb,
with periods around $61 \pm 5$ days and $47 \pm 3$ days, respectively.

Stars \#85, \#132, and \#419 were outside the P5 field of view, so we
have only the 57 day time series obtained at BG to interpret their
light curves (see Fig. 6).  All three stars have $V-I \approx 4$ mag,
and stars \#85 and \#132 have low amplitude variations.  We
tentatively classify these two stars as irregular long period
variables of class Lb.  Star \#419 brightens and fades in $V$ during
our observations, while it remains bright in $I$.  This deviation
might indicate an epoch of dust formation, perhaps at maximum light of
a Mira with a period much longer than 57 days.  Longer time series
data for all three of these stars is needed to clarify their behavior.

We note the similarities in the light curves of stars \#1, 26, 62,
244, and 255.  We reviewed our analysis and found no errors that could
account for this behavior.  Stars of similar brightness, color, and
location (\#417, 27, and a host of non-variable stars) behave
differently, indicating that it cannot be due to systematic properties
of the sky or CCD.  These light curve similarities must be
coincidental, and we expect to see them fall out of sync in future
photometry.


In conclusion, we obtained six months of time series photometry on the
emission line object NSV~11749 and confirmed its slow photometric
variability, consistent with the determination of BK12 that this object
is a symbiotic nova.  We are continuing to monitor this field in
$BVRI$ in order to find the orbital period of the binary.
In the process of observing NSV~11749, we confirmed the variability of
one known variable, and we detected eight new variable stars in the
surrounding field.  We classify the known variable, ASAS
190744+0007.1, as an irregular long period variable (Lb) and suspect
the new variables are all red, long period variables (L).  Our
continuing observations of these stars will refine their periods and
sub-categories within the L type.

{\bf Acknowledgements:} We thank an anonymous referee for his or her
vigilance and helpful comments which greatly improved this study.
This work partially fulfills the requirements for an undergraduate
B.Sc. degree at Bowling Green State University (M.W.).  This research
has made use of the SIMBAD database, operated at CDS, Strasbourg,
France; the International Variable Star Index (VSX) database, operated
at AAVSO, Cambridge, Massachusetts, USA; and the AAVSO Photometric
All-Sky Survey (APASS), funded by the Robert Martin Ayers Sciences
Fund.



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