SN 1998ab in NGC 4704

(V and B images taken at Ouda Station, observer Daisaku Nogami)

(vsnet-alert 1642)

Dear all,

There is another SN in NGC galaxy. According to IAUC 6858, BAO SN servey have discovered SN 1998ab in NGC 4704 which locates in CVn. The position of SN is reported as: R.A. = 12h48m47s.24, Decl. = +41o55'28".3 (2000.0), which is 2" east and 12" north from the core of the host galaxy. However, the following observation and the image taken at Ouda station shows that SN locates 7-8" more eastern. Its magnitudes are also reported; Apr. 1.67UT (at discovery), 16.1 (probably CCD without filter), 4.4UT, B=16.6, V=16.4.

Spectroscopy of SN 1998ab shows that this SN resembles to the peculiar SN Ia 1991T before maximum. Si feature is weak, Fe and Ca absorptions are dominant. Note that SN 1991T was 0.5-1 mag brighter than usual(typical) SNeIa and investigated heavily.

NGC 4704 appears to be Sb galaxy almost faced-on. Estimated from its recession velocity, this galaxy is farther than Coma cluster and 8 times backward of Virgo cluster. Typical SNeIa at this distance will show about 16.5 mag at maximum, but it would be expected to become more brighter. (Of course, the distance estimate would possibly be wrong.) Further photometric observations are doubtlessly urged.

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

(vsnet-alert 1643)

> NGC 4704 appears to be Sb galaxy almost faced-on. Estimated from its

Sorry, please read "Sb" as "SBb-c".

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

V-band chart


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