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 212 (August 11, 1995)
1958+56 V1028 CYG SLOWLY FADING FROM OUTBURST
The SU UMa-type cataclysmic variable V1028 Cyg (see AAVSO Alert Notice 211) is fading
slowly from its superoutburst, as the following observations show:
Aug 1.906, 12.9, J. Pietz, Erftstadts, Germany; 1.914, 13.1, T. Vanmunster, Landen,
Belgium; 1.926, 12.9, A. Diepvens, Scheps, Belgium; 2.1438, 13.2, D. York, Abiquiu, NM;
2.1556, 13.2, York; 2.1979, 13.0, York; 2.2410, 13.0:, T. Burrows, Novato, CA; 2.891, 12.7,
Diepvens; 2.899,13.3, Pietz; 2.903,12.7, E. Broens, Mol, Belgium; 3.058,13.1, Vanmunster;
3.2396, 13.1:, W. Dillon, Missouri City, TX; 3.2542, 13.2, Burrows; 4.1507, 13.4, York;
4.2118, 13.6, Dillon; 4.2444, 13.6, Burrows; 4.876, 13.6, Pietz; 4.890, 13.0, Diepvens; 4.903,
13.7, G. Poyner, Birmingham, England; 4.970, 12.9, Broens; 5.050, 13.6, Vanmunster; 5.057,
13.5, Pietz; 5.2097, 13.6, Burrows; 5.2535, 13.6, R. Harvan, Leonardstown, MD; 5.2556,
13.6, Harvan; 5.2577, 13.5, Harvan; 5.2597, 13.5, Harvan; 5.2618, 13.6, Harvan; 5.2639,
13.5, Harvan; 5.2660, 13.7, Harvan; 5.2688, 13.6, Harvan; 5.2708, 13.6, Harvan; 5.2729,
13.6, Harvan; 5.2757, 13.6, Harvan; 5.2778, 13.5, Harvan; 5.2799, 13.6, Harvan; 5.2819,
13.6, Harvan; 5.2840, 13.6, Harvan; 5.2861, 13.6, Harvan; 5.2882, 13.6, Harvan; 5.2910,
13.5, Harvan; 5.2931, 13.5, Harvan; 5.2951, 13.6, Harvan; 5.2972, 13.6, Harvan; 5.2993,
13.5, Harvan; 5.3014, 13.6, Harvan; 5.910, 13.8, Poyner; 5.956, 13.9, Diepvens; 6.028, 13.7,
Vanmunster; 6.034, 13.6, Broens; 6.1528, 13.8, York; 6.2063, < 13.5, Dillon; 7.2333, 13.9,
Burrows; 8.0785, 13.9, J. McKenna, Upper Montclair, NJ; 8.0958, 13.7, R. Stewart,
Fairlawn, NJ; 9.2014,13.7:, Dillon; 10.2049,13.7 Dillon.
The observations by E. Broens, A. Diepvens, J. Pietz, and T. Vanmunster have been
transmitted via vsnet, which we acknowledge with thanks.
Our member, Dr. R. Zissell, Hadley, MA, has obtained 122 CCD(V) observations, on 07
August and 09 August at Williston Observatory, MA. G. Foster (AAVSO) has carried out
Fourier analysis using Date Compensated Discrete Fourier Transforms (DCDFT) and the
CLEANEST spectrum (see Foster, G. 1995, Ast. Journ. 109, 1889) on this data set. We
find modulations (superhumps) with a statistically strong period of 89.3 min. and its first
overtone of 43.3 min. in the photometric data on these two nights. Accompanying is the
light curve of R. Zissell's CCD(V) data together with the smooth fit curve using the two
frequencies above, and the periodograms of the analysis.
C. Scovil reported an error in the 2000 position of this object on the "d" and "d" "e" scale
charts distributed with AAVSO Alert Notice 212. Accompanying are and "e" scale charts
with revised values for the 2000 position of this object. Please use these charts and report
your observations to AAVSO Headquarters, indicating which comparison stars you used.
PROBABLE CHANGE IN CLASSIFICATION OF 1644-25 AF SCORPII
We have been informed by H. Duerbeck, European Southern Observatory, Chile, and by
W. Liller, Vina del Mar, Chile, that the variable star AF Sco, classified in the General
Catalogue of Variable Stars as a possible nova, is most likely a Mira variable. At
Duerbeck's request, Liller checked his nova-search photographs, and found a number of
observations to support Duerbeck's suggestion, with an approximate period of around 400
days. Liller's observations indicate that AF Sco should be at maximum in about one month,
and should be between visual magnitudes 10 and 11. Currently, AF Sco is about magnitude
12 and is brightening.
We are adding AF Sco to the AAVSO observing program. Please use the accompanying
"b" and "d" AAVSO preliminary charts prepared by C. Scovil to observe AF Sco, and report
your observations to AAVSO Headquarters. Please be sure to indicate which comparison
stars you used to observe AF Sco. Observations over the next several cycles will be
essential to defining better this star's type, period, and amplitude.
0241-00 SUPERNOVA 1995V IN NGC 1087
We have been informed by the Central Bureau for Astronomical Telegrams (IAU Circular
6197) of the visual discovery of a supernova in NGC 1087 by Robert O. Evans,
Coonabarabran, NSW, Australia, on Aug 1.8 UT, using the Australian National University
1-m telescope at Siding Spring, and being assisted by J. Jarman and T. Cragg. Evans
reported that the supernova was likely not present when he observed the galaxy with an
0.41-m reflector on July 25.
A precise position of SN 1087 for epoch 2000 is given by D. Balam, Climenhaga
Observatory (IAU Circular 6203):
R.A. = 02h 46m 26.77s Dec. = -00d 29' 55.6"
The presence of the supernova was confirmed by M. Dopita and C. Trung Hua, who used
the 2.3-m reflector to obtain an unfiltered CCD image at magnitude 15.0, 21" east and 3"
south of the galaxy center (IAU Circular 6197). S. Benetti, European Southern
Observatory, reported that preliminary reduction of a CCD spectrum (range 396-793 nm,
resolution 1 nm) taken with the Danish 1.54-m telescope at La Silla on Aug 2.40 UT
confirmed the object as a type II supernova near maximum. The spectrum showed strong
H-gamma, H-beta, and H-alpha lines with P-Cygni profiles superimposed on a blue
continuum (IAU Circular 6197). Drs. Dopita and Benetti provided us with their CCD
images, which we acknowledge with thanks.
Recent observations of SN 1087 include Aug 4.47 UT, 15.68 V, D. Balam (IAU Circular
6203); 5.166, 15.3 CCD, D. Rodriguez, Madrid, Spain; 6.156, 15.5 CCD, J. Ripero, Madrid,
Spain; 6.156, 15.5 CCD, F. Pujol, Madrid, Spain; 6.156,15.5 CCD, J. Sainz, Madrid, Spain.
Please use the accompanying "e" scale AAVSO preliminary chart prepared by C. Scovil
and the CCD(R) image by S. Benetti to observe 0241-00 SN 1087 and report your
observations to AAVSO Headquarters. Please be sure to specify which comparison stars
you used to make your estimates.
Congratulations to Bob on his latest discovery!
CHARTS AVAILABLE ON AAVSO FTP SITE
Chart links are obsolete; 11/2013 create charts using VSP at http://www.aavso.org/vsp
We have prepared electronic copies of AAVSO charts mentioned in this Alert Notice for
the following stars: SN 1995V in NGC 1087, AF Sco, V1028 Cyg. They are available from
our FTP site:
ftp.aavso.org (198.116.78.2), in /pub/alert212
The answering machine at AAVSO Headquarters is on nights and weekends for your
convenience. Please call our charge-free number (800-642-3883) 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 significant astronomical observations and efforts.
Good observing!
Janet A. Mattei
Director
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