Skip to main content

Web Publications


AAVSO: Alert Notices AAVSO HOME > publications > alerts

Alert Notices


          THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
                25 Birch Street, Cambridge, MA 02138 USA
                       INTERNET:  aavso@aavso.org
                Tel. 617-354-0484       Fax 617-354-0665

                  AAVSO ALERT NOTICE 274 (May 1, 2000)

1846-01D  PROBABLE NOVA IN AQUILA = CI AQUILAE??

We have been informed by the Central Bureau for Astronomical Telegrams (IAU
Circular 7409) that Kesao Takamizawa, Saku-machi, Nagano, Japan, discovered
an apparent nova photographically at magnitude 10.0 on 5-minute exposures taken
on Apr. 28.669 and 28.673 UT, using unfiltered T-Max 400 film and twin 0.10-m
f/4 patrol cameras.  Nothing appears at the location of the object down to
magnitude 13.5-15.0 on films taken by Takamizawa between 1994 May 12 and 2000
Apr 11.

Tai-ichi Kato, Kyoto University, Japan, reported that Minoru Yamamoto, Aichi,
Japan, independently discovered the object on Apr. 28.694 UT at photographic
magnitude 9.8, using T-Max 400 film (IAU Circular 7409).

H. Yamaoka, Kyushu University, Japan, (IAU Circular 7411) measured a CCD(V)
image obtained by K. Ayani and K. Shirakami using the Bisei Astronomical
Observatory 1.01-m telescope, and reported the position of the object as:

     R.A. = 18h 52m 03.55s    Decl. = -01 degree 28' 38.9" (equinox 2000.0)

This new object is extremely close to the position of CI Aql, which was
discovered as an possible nova in 1917, reaching a maximum of photographic
magnitude 11.  No additional rebrightenings of CI Aql have been observed, and
it is not clear whether the star currently in outburst is CI Aql or a
different star.  The nature of CI Aql is uncertain; see IBVS 4232 and 4338
for more information (IAU Circular 7409).

Spectroscopic observations were obtained by M. Uemura and T. Kato, Kyoto
University, Japan, who obtained low-dispersion spectra on Apr. 29.6 UT, using
the Okayama Astrophysical Observatory 1.88-m telescope, that they reported
indicate the object to be a fast nova a few weeks after maximum (IAU Circular
7409).  W. Liller, Vina del Mar, Chile, reported that CCD spectroscopy done
by him shows H-alpha 4.3 times the intensity of the neighboring continuum, as
well as the presence of [O I], He II, and H-beta, and the absence of Fe II
(IAU Circular 7411).

Magnitude estimates reported to the AAVSO include:  Apr. 28.260 UT, 9.8
photovisual, W. Liller, Vina del Mar, Chile (using hypersensitized Tech Pan
film and orange filter; IAU Circular 7411); 29.654, 9.8, S. Takahashi,
Shiga, Japan (via Kato; IAU Circular 7409); 29.708, 10.0, H. Hirosawa, Aichi,
Japan (via Kato; IAU Circular 7409); 29.731, 9.3, H. Maehara, Saitama, Japan
(via Kato; IAU Circular 7409); 29.986, 9.4, M. Reszelski, Szamotuly, Poland;
30.003, 9.3, Reszelski; 30.0451, 9.4, P. Dubovsky, Podbiel, Slovakia; 30.063,
9.4, Reszelski; 30.117, 9.6:, G. Poyner, Birmingham, England; 30.360, 8.87
CCD(broadband V), Liller (IAU Circular 7411); 30.398, 8.95 CCD(broadband V),
Liller (IAU Circular 7411); 30.980, 9.1, K. Hornoch, Lelekovice, Czech
Republic (IAU Circular 7411); 30.988, 9.7, Reszelski; May 01.044, 8.83 CCD(V),
D. Hanzl, Brno, Czech Republic (IAU Circular 7411); 01.055, 9.6, D. Overbeek,
Edenvale, South Africa; 01.083, 8.9, M. Lehky, Hradec Kralove, Czech Republic
(IAU Circular 7411); 01.0868, 9.1, Dubovsky; 01.088, 9.7, Reszelski; 01.094,
9.3, P. Schmeer, Bischmisheim, Germany; 01.122, 9.2, Schmeer; 01.132, 9.2,
Schmeer; 01.3097, 9.1, C. Scovil, Stamford, CT.

Accompanying is an AAVSO "d" scale Preliminary chart, prepared by C. Scovil,
of CI Aql and showing two other variables, V1363 Aql and V1364 Aql.  Note that
the object currently in outburst is extremely close to the position of CI Aql
and may in fact be CI Aql.  Please report your observations of 1846-01D
N Aql 00 to AAVSO Headquarters.  Please be sure to indicate which comparison
stars you used to make your observations.

Congratulations to Kesao Takamizawa and Minoru Yamamoto on their discoveries
of this probable nova!

CHARTS AVAILABLE ON AAVSO WEB AND FTP SITES

Electronic copies of the chart of CI Aql mentioned in this Alert Notice are
available through our newly-redesigned web site at the following address:

                         http://www.aavso.org

The charts may also be obtained directly from our FTP site:

             ftp.aavso.org (198.116.78.5), in /alerts/alert274

The answering machine at AAVSO Headquarters is on nights and weekends for
your convenience. Please call our charge-free number (888-802-STAR =
888-802-7827) to report your observations. We also encourage observers to
send observations by fax to 617-354-0665 or by e-mail through the Internet
to observations@aavso.org.

Many thanks for your valuable astronomical contributions and your efforts.

Good observing!

Janet A. Mattei
Director

Elizabeth O. Waagen
Senior Technical Assistant


Keywords:
AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484