[vsnet-alert 1734] Re: (fwd) SN1998ar confusion (Rodriguez)

[Yamaoka Hitoshi <yamaoka@rc.kyushu-u.ac.jp>]

Dear SN identifiers ;-),

Diego Rodriguez wrote:

>There seems to be some confusions about the position
>and idetification of recently appeared SN 1998ar 
>
>1 There is a foreground star of mag =15, on the 
>oposite (Northeast)the star is present in the Vickers CCD Atlas 

According to IAUC 6877 which reported the discovery of SN 1998ar, this
SN locates northeast from the center of the host. I wonder why Diego
says "oposite".... However, according to DDS image, there are some
stellar-like points around NGC 2916. Among them, the brightest one
(about 16 mag) locates 9" west and 35" north from the nucleus of the
galaxy. It can be a foreground star, or a condensation in the host. 
At the reported SN position, there is a blobby structure of the host
galaxy. Sorry I cannot access to the Vickers CCD Atlas.... (is it able
to access via network?)

Fortunately, J. Wentworth, one of the reporters of magnitude estimates
of SN 1998ar on vsnet or ISN, gives a CCD image on Apr. 24.1UT on WWW
at http://vsnet.ggw.org/asras/snimages/sn98ar1.html . It clearly shows
the stellar-like object stated above and the point-like source near to
the SN position. These two are about the same magnitudes. However, the
possibility that the point-like object at the SN position is the
merged blobs by seeing effect cannot be rejected. 

>3 Unfiltered CCD images of the same field take on 
>April 25.95 show no SN at this position (limiting mag= 17) 

Could you compare it with Dr. Wentworth's one? 

>Spectroscopic observations woul be important.

I agree. However, the spectroscopy of the object dimmer than 17 mag is
not so easy as performed by 1-m telescope or so. 

Sincerely,
Hitoshi Yamaoka, Kyushu Univ., Japan
yamaoka@rc.kyushu-u.ac.jp

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