R. Fesen, R. Kremer, D. Patnaude, D. Milisavljevic
Although the connection of the Chinese "guest" star of 393 AD with the
Galactic supernova remnant RX J1713.7-3946 (G347.3-0.5) made by Wang et al. in
1997 is consistent with the remnant's relatively young properties and the guest
star's projected position within the `tail' of the constellation Scorpius,
there are difficulties with such an association. The brief Chinese texts
concerning the 393 AD guest star make no comment about its apparent brightness
stating only that it disappeared after 8 months. However, at the remnant's
current estimated 1 - 1.3 kpc distance and A_v ~ 3 mag, its supernova should
have been a visually bright object at maximum light (-3.5 to -5.0 mag) and
would have remained visible for over a year almost regardless of its supernova
subtype. The peak brightness ~ 0 magnitude adopted by Wang et al. and others
would require the RX J1713.7-3946 supernova to have been an unusually
subluminous supernova event. We also note problems connecting SN 393 with a
European record in which the Roman poet Claudian describes a visually brilliant
star in the heavens around 393 AD that could be readily seen even in midday.
Although several authors have suggested this account may be a reference to the
Chinese supernova of 393, Scorpius would not be visible near midday in March
when the Chinese first reported the 393 guest star. We review both the Chinese
and Roman accounts and calculate probable visual brightnesses for a range of
supernova subtypes and conclude that neither the Chinese nor the Roman
descriptions are easily reconciled with an expected RX J1713.7-3946 supernova
brightness and duration.
View original:
http://arxiv.org/abs/1112.0593
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