Brightening of an object in NGC 613 (Sculptor)

American Association of Variable Star Observers (AAVSO)
Tue, 09/20/2016 - 15:54

Victor Buso from the Asociación Santafesina de Astronomía (ASA, Rosario, Argentina) reports a brightening of an object in a Southern spiral arm of the galaxy NGC 613 in Sculptor.

The star is approximately at 01 34 14.46 -29 26 25.0 (J2000.0) and is barely visible in some DSS plates around mag. 22 or so.
In Victor's image (attached to this post) taken on September 20 at 04.34 UT, the object is around mag. 19 (unfiltered).

It can be clearly seen in this ESO image.

If there is someone able to take some images of the galaxy, observations are encouraged.

Since NGC 613 is 65 million light years away a supernova in that galaxy should be brighter, thus unless it has been caught in the very early stage, I think this might be a FUOR, an SDOR or even a nova.
It didn't look brighter in DSS red or infrared images so it doesn't seem to be a CCD response issue.

Best wishes,

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American Association of Variable Star Observers (AAVSO)
Supernova confirmed

Victor Buso took more images the following night and confirmed the object was real and had brightened more than 3 magnitudes!!
It was later confirmed by ASAS-SN.

It is currently mag. 14 and rising.

It has been publishd in the Transient Name Server as AT 2016gkg.

It will keep rising for some days althoug more slowly. If it is a type II supernova I predict it will reach 13rd magnitude.
Let's see what happens.


American Association of Variable Star Observers (AAVSO)
SN 2016gkg (AT2016gkg) - AAVSO Special Notice #421

AAVSO Special Notice #421 reports on SN 2016gkg in NGC 613 (Scl), the unusual Type-II supernova discovered by AAVSO observer Victor Buso. This object was first announced as AT2016gkg. Please see the Notice for details and observing instructions.

Many thanks, and good observing,

Elizabeth Waagen, AAVSO HQ