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\input ibvs2.sty

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\IBVShead{4904}{2 June 2000}

\IBVStitle{CI Aquilae in 1917}


\IBVSauth{Williams, David B.}

\IBVSinsto{P.O. Box 58, Whitestown, IN 46075, USA, e-mail: dbwilyumz@aol.com}

\SIMBADobjAlias{CI Aql}{Nova Aql 1917}
\IBVSkey{CI Aql, Nova Aql 1917}

\begintext

The 1917 outburst of CI Aquilae, a possible nova, is known from a single
observation (Reinmuth 1925). The maximum of the current outburst was
much brighter than Reinmuth's estimate of approximately magnitude 11
ptg (blue). To obtain a more complete record of the 1917 event, I
examined the Harvard College Observatory patrol plates for the year
1917. The following estimates were made using Tycho B magnitudes for
nearby comparison stars.

\begin{center}
\begin{tabular}{cr}
\hline
HJD & Mag.\\
(2421000\,+) & (BT)\\
\hline 
364.749 & $<$10.5\\
366.805 &  10.0\\
368.768 &   8.6\\
369.730 &   8.6\\
374.786 &   9.6\\
379.733 &   9.9\\
393.754 &  11.3\\
397.751 &  11.5\\
403.722 &  11.7\\
\hline
\end{tabular}
\end{center}

CI Aql was invisible, fainter than 10.5 and usually less than 11.4, for all
earlier and later dates during 1917.

I am grateful to Martha Hazen, curator of astronomical photographs at HCO,
for access to the patrol plates and to Kerriann Malatesta of the AAVSO
technical staff for preparing this note for publication.

\reference

Reinmuth, K., 1925, {\it Astron.\ Nach.}, {\bf 225}, 385.

\endreferences

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