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Alert Notice 262: 1415-68 Nova Circini 1999 AND Fading of 1544+28A R Coronae Borealis AND Update on two recent novae (V1493 Aql, V382 Vel) and AM Herculis [DD Cir]

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 262 (August 25, 1999)

1415-68 NOVA CIRCINI 1999

We have been informed by  William Liller, Vina del Mar, Chile, and
by the Central Bureau for Astronomical Telegrams (IAU Circular 7242,
http://cfa-www.harvard.edu/iau/Headlines.html) of Liller's photographic
discovery, using the PROBLICOM method, of a nova in Circinus, on
August 23.0110 and Aug. 23.0125 UT, at photographic magnitude 7.7.
The photographs were taken on Technical Pan film with an 85-mm camera
lens and an orange filter.

The position of the nova as obtained from CCD frames taken with 0.20-m
Schmidt camera on Aug. 23.9717 UT was:

 R.A. = 14hr 23m 23.6s   Decl. = -69degrees 08' 45.1" (equinox 2000)

The magnitude measured with a broadband V filter was 7.79 at that time.

Liller further reports that nothing brighter than magnitude 11.0 appears
at this location on two photographs taken on July 15.99.  A low resolution
spectrum obtained with the Schmidt, an objective prism, and a CCD, on
Aug. 23.9874 UT shows H-alpha in emission at a level ~0.85 times brighter
than the intensity of the surrounding continuum.  The spectrum suggests
that the nova outburst occurred a day or two earlier.

Additional observations of N Cir 99 reported to the AAVSO include:
Aug. 24.3021 UT, 8.4, A. Jones, Nelson, New Zealand; 24.4222, 7.6, R.
Stubbings, Drouin, Victoria, Australia; 24.4396, 7.5, Stubbings; 24.4465,
7.6, Stubbings; 24.4500, 7.5, Stubbings; 24.4528, 7.6, Stubbings; 24.4583,
7.6, Stubbings; 24.4625, 7.6, Stubbings; 24.4681, 7.5 Stubbings; 24.4701,
7.6, Stubbings; 24.4722, 7.5, Stubbings; 24.4771, 7.6, Stubbings; 24.581,
8.1, A. Pearce, Nedlands, Australia; 24.707, 8.7, L. Monard, Pretoria,
South Africa; 24.777, 8.8, Monard; 24.790, 8.5, B. Fraser, Sunninghill,
South Africa; 24.844, 8.7, J. Hers, Sedgefield, South Africa; 25.459, 8.1,
Pearce; 25.501, 8.0, Pearce; 25.538, 8.1, Pearce; 25.937, 8.1, J. Garcia,
Buenos Aires, Argentina.

Accompanying is a CCD-V image of N Cir 99 obtained by William Liller on
Aug. 23.9717. The field measures 27' by 36'.

Also accompanying is a "c" scale AAVSO preliminary chart of N Cir 99
prepared by C. Scovil. Please use this chart to observe 1415-68 N Cir 99,
and report your observations to AAVSO Headquarters, making sure to indicate
which comparison stars you used to make your magnitude estimate.

Congratulations to Bill on his latest discovery!

FADING OF 1544+28A  R CORONAE BOREALIS

We have been informed by our observers that R Coronae Borealis, the
prototype of the R CrB stars, is fading.  R CrB, which is approximately
visual magnitude 6.0 at maximum, is reported to be at approximate magnitude
11.4 as of August 24 UT.  Observations of R CrB reported to the AAVSO since
July 15th indicate that this star began to fade in late July.

The last fading of this star occurred in August 1998 - March 1999, during
which R CrB faded to visual magnitude 8.4, brightened to magnitude 7.2, faded
once again to magnitude 9.6, and then recovered.

Fadings of R CrB are unpredictable both in duration and in the magnitude to
which the star may fade.  Please monitor R CrB closely and report your
observations of this interesting star to AAVSO Headquarters.

AAVSO "a", "b", "c", "d", and "e" scale standard charts for R CrB have
been posted on our ftp site; see below for details. Those needing paper
copies of these charts should contact AAVSO Headquarters.

UPDATE ON TWO RECENT NOVAE AND AM HERCULIS

1903+12 V1493 AQUILAE (N AQL 99)

V1493 Aql was discovered in mid-July at photographic magnitude
8.8 (see AAVSO Alert Notice 261).  Observations reported to the AAVSO
indicate that the nova had faded to approximate visual magnitude 12.8
by early August, and then began to slowly brighten. The nova is reported
to be at visual magnitude 12.0 as of August 24 UT.

AAVSO "c", "d", and "e" scale preliminary charts for V1493 Aql (N Aql 99)
have been posted on our ftp site; see below for details. Those needing paper
copies of these charts should contact AAVSO Headquarters.

1040-51 V382 VELORUM (N VEL 99)

V382 Vel was at approximate visual magnitude 3.0 at the time of its
discovery in May (see AAVSO Alert Notice 259).  AAVSO observations
indicate that since its discovery the nova has continued to slowly fade.
The nova is reported to be at visual magnitude 7.9 as of August 22 UT.

AAVSO "aa" and "b" scale preliminary charts for V382 Vel (N Vel 99) have
been posted on our ftp site; see below for details. Those needing paper
copies of these charts should contact AAVSO Headquarters.

1813+49 AM HERCULIS

AAVSO observations indicate that the magnetic variable AM Her is
currently brightening from its recent low state.  AM Her began fading
in May and reached visual magnitude 15.2 in early July.  Observations
reported to the AAVSO since July 1st show that AM Her remained at its
low state until mid-August when it began to brighten.  The variable is
reported to be at visual magnitude 13.4 as of August 25 UT.

AAVSO "b", "d", and "f" scale preliminary charts for AM Her have been
posted on our ftp site; see below for details. Those needing paper copies
of these charts should contact AAVSO Headquarters.

LIGHT CURVES

The light curves (through June 1999) of the objects mentioned in this
Alert Notice may be plotted on our web site (www.aavso.org) by clicking
on "Light Curves" and using the online light curve generator.  We are
currently processing the monthly reports of observations made in July.
Therefore, the July data can not yet be accessed with the light curve
generator.

Observations which have been reported on a nightly basis since July 1,
1999, can be viewed via our web page in the AAVSO "Quick Look" File.

CHARTS AVAILABLE ON AAVSO WEB AND FTP SITES

Chart links are obsolete; 11/2013 create charts using VSP at http://www.aavso.org/vsp

Electronic copies of the N Cir 99 chart, the CCD(V) image of N Cir 99, and
the other charts mentioned in this Alert Notice are available through our
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/alert262)

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.

If you need to change the email address this Alert Notice is sent to, or
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                 http://www.aavso.org/mailinglists.stm

Many thanks for your valuable astronomical contributions and your efforts.

Good observing!

Janet A. Mattei       Rebecca Pellock             Kerriann Malatesta
Director                 Technical Assistant         Technical Assistant

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