Skip to main content

Web Publications


		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

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

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