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\IBVShead{4603}{18 June 1998}

\IBVStitletl{Photometry of stars in the field of HP Andromedae}{ (and a new red variable)}

\IBVSauth{Brian A. Skiff}
\IBVSinsto{Lowell Observatory, 1400 West Mars Hill Road, Flagstaff\enskip
           AZ\quad 86001-4499, USA}
\vskip -1mm
\IBVSinsto{e-mail:  bas@lowell.edu}


\IBVSkey{photometry}
\SIMBADobj{HP And}
\SIMBADobj{GSC 2790-1851}
\begintext

     HP Andromedae (0\hr19\mm09\fsec07 \enskip +41\deg27\arcm41\farcs9 (2000,
USNO--A1.0) is a poorly-studied dwarf nova normally about 18\mm\, in quiescence
but reaching 10\fmm5 during outbursts.  At the request of AAVSO chartmaker
Charles Scovil, I observed several stars in the field suitable as comparisons
for visual observers while the star is bright.  The results have been
distributed via the `VSNET' list-server (Skiff 1995a,b), but are published here
as a matter of record.  Large-scale charts prepared using this sequence have
been made available on the Web by the AAVSO ({\tt ftp://ftp.aavso.org/pub/charts/and/hp\_and}).

     I measured the stars on several nights in 1992 and 1995 using the Lowell
53cm photometric telescope.  Str\"{o}mgren $y$ and $b$ filters were used
through either 19- or 29-arcsec diaphragms.  Each observation consisted of at
least three 10\sec\, integrations on `star' and two 10\sec\, integrations on
`sky', with more integrations for stars fainter than V $\sim$9\mm.  A dozen
or more primary and secondary standards were observed each night for
calibration to Johnson V and Str\"{o}mgren {\it b--y}.  Per-star residuals from
the linear fits to the standards averaged 0\fmm007 in V and 0\fmm005 in
{\it b--y}.

     Results for the stars near HP And are shown in Table 1, sorted in order
of decreasing brightness.  The stars are identified by HD, BD, or GSC number;
positions come from the ACT (Urban {\it et al}.\ 1997) or the GSC version 1.2
(STScI 1996).  The standard deviations of the mean values in V and {\it b--y}
are given on the second line of each entry.  Tycho BV photometry for the two
brightest stars is given in the notes.

     Misselt (1996) has also published BVR photometry for stars close to the
variable.  His results are particularly useful when HP And is faint.  As has
been noted by Henden \& Honeycutt (1997), Misselt's V magnitudes have a small
zero-point offset, amounting to +0.03--0.04 (Misselt too faint), similar to
what is found here for the few stars in common.

\bigskip

{\bf  A new red variable}

     While measuring stars in this field, I found that BD+40\deg51 =
IRAS 00163+4120 = GSC 2790-1851 (0\hr19\mm02\fsec6 \enskip +41\deg37\arcm41\arcs\,
[2000]) is very red, with a {\it b--y} color corresponding to B--V $\sim$2.3.
Subsequent observations show that the star is variable with a range of nearly
a full magnitude.  This is probably a semiregular variable with a period near
three months.  The IRAS identification was easy to make, but the star does not
appear in the Dearborn catalogue (Lee {\it et al.}\ 1947), so no spectral type
is available.  My five observations are collected in Table 2.



\begin{center}
{\small Table 1: Photometry of Stars in the Field of HP Andromedae}
\vskip 2mm
\begin{tabular}{lccrrcl}
\hline
Name & \multicolumn{2}{c}{RA  (2000)  Dec}& \multicolumn{1}{c}{V}& \multicolumn{1}{c}{\it b--y}& n & Remarks \\
\hline
HD 1469*      & 0 19 03.2 & +41 26 38 &  9.230 &--0.012 & 2 & A0 \\
              &           &           &   .011 &   .004 &   &  \\
BD+40\deg54*  & 0 19 31.5 & +41 37 09 & 10.270 &  0.533 & 3 & GSC 2790-1458 \\
              &           &           &   .014 &   .004 &   &  \\
BD+40\deg53   & 0 19 13.6 & +41 45 28 & 10.831 &  0.711 & 2 & GSC 2790-0356 \\
              &           &           &   .011 &   .006 &   &  \\
GSC 2790-1158 & 0 18 42.9 & +41 31 19 & 11.480 &  0.388 & 2 &  \\
              &           &           &   .004 &   .009 &   &  \\
GSC 2790-1753 & 0 19 06.4 & +41 28 05 & 11.739 &  0.641 & 2 &  \\
              &           &           &   .005 &   .009 &   &  \\
GSC 2790-1885 & 0 19 17.1 & +41 26 27 & 14.00  &  0.43  & 2 &  \\
              &           &           &   .05  &   .04  &   &  \\
\hline
\end{tabular}
\begin{tabular}{lrll}
Notes: & HD 1469 & Tycho V = 9.25$\pm$0.02,  & B$-$V = $-0.05\pm$0.02. \\
   & BD+40\deg54 & Tycho V = 10.20$\pm$0.04, & B$-$V = 1.01$\pm$0.07. \\
\end{tabular}
\vskip 8mm

{\small Table 2: Photometry of BD+40\deg51}
\vskip 2mm
\begin{tabular}{lcc}
\hline
JD 2400000+ & V & {\it b--y} \\
\hline
48800.9  & 11.670 &  1.685 \\
50004.8  & 10.947 &  1.549 \\
50010.8  & 10.967 &  1.533 \\
50044.8  & 11.228 &  1.571 \\
50095.7  & 10.801 &  1.491 \\
\hline
\end{tabular}
\end{center}
\vskip 8mm

  I would like to thank Margareta Westlund and Karl Gustav Andersson for
pointing out an identification error in my original `VSNET' post.



\references

Henden, A. A., and Honeycutt, R. K., 1997, {\it Publ.\ Astron.\ Soc.\ Pac.},
{\bf 109}, 441

Lee, O. J., Baldwin, R. J., Hamlin, D. W., Bartlett, T. J., Gore, G. D., and
Baldwin, T. J., 1947, Ann.\ Dearborn Obs., {\bf 1}, 5

Misselt, K. A., 1996, {\it Publ.\ Astron.\ Soc.\ Pac.}, {\bf 108}, 146

Skiff, B. A., 1995a,\\ {\tt http://www.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet/msg00261.html}

Skiff, B. A., 1995b,\\ {\tt http://www.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet/msg00367.html}

Space Telescope Science Institute, 1996,\\ {\tt http://www-gsss.stsci.edu/gsc/gsc12/description.html}

Urban, S. E., Corbin, T. E., and Wycoff, G. L., 1998, {\it Astron.\ J.},
{\bf 115}, 2161

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