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Alert Notice 163: Supernova in NGC 2082 AND Fading of 2007+20 FG Sagittae

THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
25 Birch Street, Cambridge, MA 02138 USA
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AAVSO ALERT NOTICE 163 (October 2, 1992)

SUPERNOVA IN NGC 2082

The Central Bureau for Astronomical Telegrams (IAU Circular 5625) has informed us of the visual discovery by Robert Evans, Hazelbrook, Australia, of a supernova in NGC 2082 on Sep. 30.75 UT at approximately magnitude 14.0. The supernovs is located about 1' west of the galaxy nucleus, whose 1950 position is:

R.A.  05 41 36   Dec. -64 20

M. M. Phillips at the Cerro Tololo Interamerican Observatory reports that the spectrum obtained on Oct. 1.36 UT indicates the supernova to be of Type-II and very likely discovered at an early epoch.

Please use the enclosed charts to observe 0541-64 SN 2082, and report your observations to AAVSO Headquarters.

Our congratulations to Bob on his latest discovery!

FADING OF 2007+20 FG SAGITTAE

FG Sagittae, the central star of a planetary nebula, has been fading since late August from its average maximum magnitude of 9.2, and has reached magnitude 13.4, as observations from our observers indicate in the accompanying light curve.

FG Sge was discovered to be variable in 1894 when it began brightening from photographic magnitude 13.6. It brightened gradually, reaching about 9.2 by the mid 1960's. It was added to the AAVSO observing program in 1968, and observations indicate that it had been at about 9.2 magnitude with some small-amplitude fluctuations on the order of half a magnitude until it began to fade in late August.

Observers should beware of a star extremely close to FG Sge - its separation is only 8-10 arcseconds. Monsignor R. Royer reported that this "companion" star brightened this summer from fainter than 13th magnitude, reached approximately magnitude 12.1, and is presently at magnitude 12.5.

Please use the accompanying AAVSO 'e' scale chart of FG Sge. The "companion" star is indicated as "var?" on the chart and is located even closer to FG Sge than was possible to indicate on the chart.

Many thanks to observers who have been keeping us informed of this unprecedented fading of FG Sge. Please keep a close eye on this interesting variable and call in your observations to Headquarters. The answering machine (617-354-0484) is on nights and weekends for your convenience.

When sending in your monthly observation report, please use the following designations and names for objects in the FG Sge field:

2007+20  FG Sge
2007+20A  ST Sge
2007+20C Var? N
2007+20D  Var? E (= "companion")

 

INSERT FG SGE LIGHT CURVE

Thank you very much for your enthusiastic response to the EUVE project. The observations called in to the AAVSO are regularly transmitted to the Center for EUV Astrophysics and are very much appreciated!

Good Observing!

Janet A. Mattei
Director

files: FG Sge light curve; SN 1987A chart (use for SN 2082) with insert from AAVSO Variable Star Atlas; FG Sge 'e' scale chart

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