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 252 (October 23, 1998)
1749-31 NOVA SCORPII 1998
We have been informed by William Liller, Vina del Mar, Chile, and by the
Central Bureau for Astronomical Telegrams (IAU Circular 7034) of Liller's
photographic discovery, using the PROBLICOM method, of a probable nova in
Scorpius on October 21.0266 UT at magnitude 6.9, using Tech Pan film and an
85-mm camera lens with orange filter. The nova appeared on two other films
taken by Liller on October 21.0293 and 21.0389 UT. It does not appear down
to magnitude 11.5 on photographs taken by Liller on October 17.010.
Visual confirmation was made by Albert Jones, Nelson, New Zealand, who
reported the nova at magnitude 8.4 on October 22.4306 UT, using Tycho VT
magnitudes for the comparison stars. Gordon Garradd, Loomberah, NSW,
Australia, reported the nova at unfiltered CCD magnitude 7.4 on October
22.4091 UT, and gave the following precise position of the nova:
R.A. = 17h 55m 24.99s Decl. = -31 degrees 01' 41.5" (equinox 2000)
Additional observations of N Sco 98 reported to the AAVSO include: October
22.717, 8.3, D. Overbeek, Edenvale, South Africa (SAO 209463 and SAO 209474
used as comparison stars); 22.756, 8.6, B. Monard, Pretoria, South Africa
(Hipparcos/Tycho magnitudes used to make estimate); 22.780, 8.6, J. Hers,
Sedgefield,South Africa; 23.1090, 8.5, R. Royer, Lakewood, CA; 23.725, 9.0,
Monard.
Accompanying is a CCDV image of N Sco 98 obtained by Monsignor Ronald Royer,
Lakewood, CA, on October 23.1090 UT. The field of view is 20' x 13'.
Also accompanying is an AAVSO preliminary 'c' scale chart of N Sco 98,
prepared by Charles Scovil. Please use this chart to observe 1749-31 N Sco 98,
and report your observations to AAVSO Headquarters, making sure to indicate
which comparison stars you used to make your magnitude estimates.
Congratulations to Bill on his latest discovery!
CHARTS AVAILABLE ON AAVSO WEB AND FTP SITES
Chart links obsolete, 11/2013: Create charts using VSP at http://www.aavso.org/vsp
Electronic copies of the AAVSO chart of N Sco 98 mentioned in this Alert
Notice are available through our web site at the following address:
http://www.aavso.org
All of these charts may also be obtained directly from our FTP site:
ftp.aavso.org (198.116.78.5), in /pub/alerts/alert252/
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
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