cf. vsnet-chat 1195 http://www.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-chat/msg01195.html cf. vsnet-chart 82 http://www.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-chart/msg00082.html
Dear SN watchers,
According to IAUC 6998, Australian amateur astronomer B. White has visually discovered an apparent supernova in SBb galaxy NGC 6754, which has also produced SN 1998X this March! The new object, SN 1998dq, is located at R.A. = 19h11m23s.78, Decl. = -50o38'25".5 (2000.0), which is about 19" west and 5" north from the core of the galaxy. This position is about 5-7" north from SN 1998X.
SN 1998X was 17 mag on its discovery and was of type II. On the other hand, SN 1998dq was 14.3 mag around the discovery (Aug. 23.4), and from its unusual blue (B-V about 0) color it would be on very early phase of bright supernova. From the recession velosity of the galaxy, the expected maximum of typical SNe Ia on this galaxy would be 14.9 mag, while SN 1998dq is already brighter. Further photometry and spectroscopy (which has not reported) are strongly urged.
Such an event is rare as two supernovae appears in one galaxy on the same year. Recent example is SNe 1992R and 1992ac, which are produced by MCG +10-24-007.
Hitoshi Yamaoka, Kyushu Univ., Japan
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